现代麻醉学的趋势已经向亚麻醉学科发展，我国也已经成立了相应的各麻醉学组。
现从一个病例深入讨论门诊麻醉
AMBULATORY SURGERY 门诊手术麻醉
Laurence M. Hausman, MD
James N. Koppel, MD
A 38-year-old woman is scheduled for an ambulatory diagnostic pelvic laparoscopy at 3 o’clock in the afternoon. She arrives 1 hour before scheduled surgery with her 11-year-old son and appears to be extremely apprehensive. Prior medical history is significant for asymptomatic esophageal reflux, long-standing stable asthma that has been successfully treated with inhaled sympathomimetics and steroids, and juvenile-onset diabetes mellitus, currently controlled with 25 U neutral protamine Hagedorn (NPH) and 6 U regular insulin every morning and 10 U NPH and 3 U regular insulin every night.
一个38岁妇女安排下午3点做盆腔镜诊断性检查术。术前1小时和11岁的儿子一起到了，但是看起来非常不安。先前的病史显示她有明显的无症状性食管返流，哮喘经过吸入拟交感神经药物和甾体类激素治疗处于长期稳定状态，青少年型糖尿病用25U低精蛋白锌胰岛素（NPH）和每天早上6U常规胰岛素，夜里10UNPH和3U常规胰岛素控制。
QUESTIONS
1.Are there advantages to performing surgery on an ambulatory basis?
2.Which patients are considered acceptable candidates for ambulatory surgery?
3.Are there any patients who should never have surgery on an ambulatory basis?
4.Are diabetic patients suitable candidates for ambulatory surgery?
5.What types of surgical procedures are appropriate for ambulatory surgery?
6.What is the appropriate fasting time before ambulatory surgery that necessitates an anesthetic?
7.Should drugs be administered to empty the stomach or change gastric acidity or volume before the administration of an anesthetic?
8.How can patients be appropriately screened for anesthesia when ambulatory surgery is planned?
9.What preoperative laboratory studies should be obtained before surgery?
10.Should an internist evaluate each patient before ambulatory surgery?
11.Is anxiolytic premedication advisable before ambulatory surgery, and what agents are appropriate?
12.What are the reasons for last-minute cancellation or postponement of surgery?
13.What is the ideal anesthetic for ambulatory surgery?
14.Are there relative or absolute contraindications to the administration of a general anesthetic in the ambulatory setting?
15.What are the advantages and disadvantages to performing a conduction anesthetic in the ambulatory patient?
16.What are the advantages and disadvantages of selecting a nerve block technique for the ambulatory patient?
17.Describe the intravenous regional anesthetic technique (Bier block) for surgery on the extremities.
18.What sedatives can be administered to supplement a regional anesthetic?
19.What complications of nerve block anesthesia are of special concern to the ambulatory patient?
20.Should patients having ambulatory surgery be tracheally intubated?
21.What is the role of propofol in ambulatory surgery?
22.What is total intravenous anesthesia (TIVA), and what are its advantages and disadvantages?
23.What is moderate sedation, when is it employed, and what advantages does it offer?
24.When tracheal intubation is required for a short procedure, can one avoid the myalgias associated with succinylcholine?
25.Can a relative overdose of benzodiazepines be safely antagonized?
26.Do the newer volatile agents offer advantages over enflurane and isoflurane?
27.What are the etiologies of nausea and vomiting, and what measures can be taken to decrease their incidence and severity?
28.How is pain best controlled in the ambulatory patient in the postanesthesia care unit (PACU)?
29.What discharge criteria must be met before a patient may leave the ambulatory surgery center?
30. What are the causes of unexpected hospitalization following ambulatory surgery?
31.When may patients operate a motor vehicle after receiving a general anesthetic?
32.What is the role of aftercare centers for the ambulatory surgery patient?
33.Are quality assurance and continuous quality improvement possible for ambulatory
1. 在门诊手术的优点在哪里？
2. 哪些病人可以接受门诊手术？
3. 哪些病人一定不能在门诊进行手术？
4. 糖尿病人适合门诊手术吗？
5. 门诊手术包括的种类有哪些？
6. 门诊手术麻醉合适的禁食时间是多少？
7. 麻醉前是否使用药物促进胃排空，改变胃液酸度和胃液量？
8. 怎么适当拒绝对已经安排门诊手术的病人进行麻醉？
9. 术前需要知道那些实验室检查结果？
10. 每个门诊手术病人都要进行内科评估吗？
11. 门诊手术前建议给抗焦虑药吗？哪些药物合适呢？
12. 最后一次取消或推迟手术的原因？
13. 什么是门诊手术的理想麻醉？
14. 有没有门诊手术全麻的相对或绝对禁忌证？
15. 对门诊手术施行部位麻醉的优缺点？
16. 对门诊手术选择神经阻滞的优缺点？
17. 描述四肢手术的静脉区域麻醉技术。
18. 哪些镇静药可以强化区域麻醉？
19. 门诊手术进行神经阻滞麻醉需要特别关注的并发症是什么？
20. 门诊麻醉需要气管插管吗？
21. 异丙酚在门诊麻醉的地位？
22. 什么是全静脉麻醉（TIVA），优缺点是什么？
23. 什么是适度镇静，给药时机和镇静的优点是什么？
24. 短小手术何时需要气管插管，能避免司可林相关的术后肌痛吗？
25. 相对大剂量的地西泮能被安全拮抗吗？
26. 新型挥发性麻醉药相对于安氟醚和异氟醚优越吗？
27. 恶心、呕吐的病因学是什么？哪些措施可以减少发生率和降低发作程度？
28. 怎么使门诊手术病人在麻醉后恢复室（PACU）得到最好的镇痛？
29. 病人离开门诊手术中心必需达到的标准是什么？
30. 门诊手术后意外住院的病人怎么处理？
31. 全麻后的病人何时能进行机动车驾驶？
32. 门诊手术病人术后服务中心的地位是什么？
33. 门诊手术安全吗？质量能持续提高吗？
1.Are there advantages to performing surgery on an ambulatory basis?
There are multiple advantages to performing surgery on an ambulatory basis. Most obviously, the patient returns much more quickly to the familiar home environment. This is especially important for both pediatric and geriatric surgical patients. Formerly, patients might have remained hospitalized for days, rather than a few hours. A reduction in the acquisition of nosocomial infections has also been noted. This is an extremely important consideration when dealing with immunocompromised patients such as organ transplant recipients or patients who are receiving chemotherapeutic agents. Furthermore, in the ambulatory model, the incidence of medication errors related to either faulty prescribing or dispensing of drugs has decreased. In addition, overall costs are usually significantly reduced. This cost saving is due in part to a decrease in the number of laboratory tests requested and medical consultations obtained, as well as pharmaceuticals dispensed. Of course, the significant expense of both the inpatient hospitalization as well as the hospital facility fee is avoided. Other less tangible advantages include ease of scheduling procedures, without having to consider variables such as operating room block time, and an improved sense of patient privacy. This occurs because most offices are staffed by a small consistent group of personnel.
As a group, ambulatory patients tend to be more aware of the effects of the anesthetic they receive than the inpatient population. Because ambulatory patients usually undergo less intrusive surgical procedures and are less ill postoperatively, an attempt is made to resume usual preoperative activities at an earlier time. Therefore, nausea, vomiting, myalgias, headache, as well as disordered sensorium and vertigo may appear to be more significant to this group of patients. Unpleasant symptoms are spontaneously reported with greater frequency than in the inpatient group, and patients may tend to focus their attention on them. These discomforting symptoms, if present postoperatively, may be recalled in a vivid fashion if an additional surgical procedure is required. The negative recall may predispose the patient to extreme anxiety.
Only a small subgroup of patients may actually prefer hospitalization to ambulatory surgery.
1. 在门诊手术的优点在哪里？
门诊手术有很多优点。首先，病人可以尽快地回到熟悉的家庭环境。这对小儿和老年病人特别重要。以前病人需要在医院呆几天而不是几个小时。减少院内感染也得到了关注。这对免疫耐受的病人如器官移植和接受化疗的病人尤其重要。而其在门诊模式下，因开错药和发错药造成错误给药的机率也降低。另外，花费也显著降低。部分原因是降低了要求的实验室检查的数量，医疗咨询费用和给药费用。住院病人治疗费和医院相关设施费用支出也得到避免。其他的包括简化手续，不必考虑手术等待时间，保护病人隐私。因为门诊手术只是一个小的团队。
作为一个群体，门诊手术病人比住院病人更加关注麻醉效果，因为门诊病人大多进行的是创伤较小，术后并发症较少的操作，他们试图尽早恢复到术前的活动状态。因此，恶心、呕吐、肌痛、头痛及意识错乱、眩晕的发生率更加显著，他们发生不愉快症状自发报告的机率也较住院病人显著频繁，这些不适症状如果在术后发生，当在需要进行另外手术时会被回忆的栩栩如生，这些回忆可能造成病人额外的焦虑。
只有很小一部分病人选择住院来接受门诊手术，
2.Which patients are considered acceptable candidates for ambulatory surgery?
For patients to be considered acceptable candidates for ambulatory surgery, generally they should have a relatively stable medical condition. However, many centers now routinely accept American Society of Anesthesiologists (ASA) physical status III and IV patients for selected, relatively noninvasive surgical procedures or diagnostic studies. Generally, less invasive surgery is performed on patients who are less healthy, while more invasive surgery is performed only on ASA physical status I or II patients. Patients with cardiovascular disease have an increased risk of perioperative complications. Those with severe physical or mental handicaps are often excluded from consideration as candidates for ambulatory surgery. The ability to comprehend and comply with postoperative instructions is mandatory to the success of ambulatory surgery.
Ambulatory surgery is well suited for the pediatric patient population. Generally, ambulatory surgical procedures commonly performed on children are shorter in duration, less extensive, and less invasive than the majority of procedures performed on adults. Additional benefits to the pediatric group include less disruption of the child’s normal feeding schedule and decreased separation time from parents. Exposure to the unfamiliar and frightening hospital milieu can be reduced to the bare minimum. Additionally, because recovery times are short for procedures such as myringotomy and tubes, circumcision, and inguinal herniorrhaphy, early discharge from the facility is feasible.
Preoperative communication and collaboration between anesthesiologists and their surgical colleagues are essential in the case of the questionable or problem patient. The surgeon who is to perform the procedure, the patient, and the family must be agreeable to the concept of ambulatory surgery. However, reimbursement schedules created by insurance carriers will often convince the occasional skeptic, because costs associated with hospitalization for procedures that can be readily performed on an ambulatory basis will usually not be covered. Overwhelming and incontrovertible evidence of medical necessity for inpatient care must be presented to obtain authorization for postoperative hospitalization.
2. 哪些病人被认为可以接受门诊手术？
对认为可以接受门诊手术的病人，一般认为需要有相对稳定的医疗状况。事实上，很多中心常规接受ASA III-IV级的病人接受相对无创或诊断性检查。一般健康条件差的病人进行创伤小的操作，而只对ASA I – II级病人施行较大创伤的手术。伴有心血管疾病的可以增加围术期并发症。那些有身体或精神残疾的病人通常被排除在考虑之外。判断预后的综合能力是门诊手术成功的关键。
门诊手术很适合儿科病人，一般，门诊手术适于相对于成人大手术时间短，范围小，创伤少的小手术。其他的包括尽量减少对儿童的进食时间的干扰，缩短和父母分开的时间，使暴露在不熟悉的和令人惊怕的医院环境中的时间减少到最小。恢复时间短的手术如鼓膜切开与置管术，包皮环切术和腹股沟疝修补术早期离开医院都是可行的。
对一些有疑问的或有问题的病人术前麻醉医生和外科同事的交流是必要的。手术医生、病人和病人家属都必须同意进行门诊手术。事实上保险公司制定的赔偿计划要说明可能发生的意外，因为住院消费将会得到更好门诊手术的还没有消除。需要术后住院治疗的证据必须明白无误地提出来并得到批准进行术后住院治疗。
3.Are there any patients who should never have surgery on an ambulatory basis?
An exception to the list of acceptable candidates is ex-preterm infants who are less than 55–60 weeks postconceptual age. These patients may have life-threatening episodes of postoperative apnea and bradycardia as many as 12 hours and up to 48 hours after receiving a general anesthetic. Therefore, in-hospital monitoring of these patients is recommended. For similar reasons, term infants less than 44 weeks postconceptual age should also have surgery performed only on an inpatient basis. Postoperative respiratory monitoring is mandatory for at least 12–18 hours. If at all possible, any required surgery or diagnostic procedures requiring the administration of either a sedative or a general anesthetic should be postponed until the child passes this period.
3.哪些病人一定不能在门诊进行手术？
在以上可以接受门诊手术列表病人中，年龄低于55-60周的新生早产儿除外。这些病人存在全麻后12-48小时出现致命性呼吸暂停和心动过缓的危险。因此对这些对病推荐进行院内监护。相同的原因，低于44周的足月新生儿只在住院后进行手术，并且术后必须进行12-18小时的呼吸监护。如果可能任何需要给镇今年给药物或全麻的手术或诊断性检查均应推迟过这个时期。
4.Are diabetic patients suitable candidates for ambulatory surgery?
Diabetic patients may present a major challenge for the anesthesiologist when scheduled for ambulatory surgery. Because of the critical nature of glucose homeostasis, it may be advisable to handle exceptionally brittle diabetics on an inpatient basis. Preoperatively, diabetic patients must be carefully assessed for the presence of end-organ damage. Cardiovascular disease, autonomic and renal insufficiency, and gastroparesis may lead to potential problems in the perioperative period.
It is preferable to schedule surgery on the insulin-dependent diabetic as the first or second case of the day. The major concerns, of course, are to avoid the extremes of plasma glucose, both hypoglycemia and hyperglycemia, as well as acidosis. Delays in insulin administration may lead to ketoacidosis despite the fasting state. For this reason, it is recommended that patients receive insulin along with a continuous infusion of dextrose on arrival at the ambulatory surgery facility. Insulin may be administered by either the subcutaneous or intravenous route. The relative advantage, if any, of administering a continuous infusion of regular insulin versus one third to one half of the usual long-acting insulin dose subcutaneously has not been demonstrated. Another option for early-morning surgical procedures is to administer the usual long-acting insulin dose subcutaneously immediately following surgery and shift the time of all meals and future insulin injections by the same offset.
Non-insulin-dependent diabetics who are controlled by one of the available oral hypoglycemic agents must also be carefully monitored in the perioperative period by periodic fingerstick or blood glucose determinations. The half-life of some of the oral agents may be as long as 60 hours (chlorpropamide). Fortunately, patients with adult-onset, non-insulin-dependent diabetes mellitus (NIDDM) rarely develop ketoacidosis. However, this group may develop hyperosmolar, nonketotic coma when significant hyperglycemia and dehydration occur.
Before discharge, it is critical that diabetic patients be capable of eating and be relatively free of significant nausea that might lead to emesis and inability to maintain adequate caloric intake.
4.糖尿病人适合门诊手术吗？
糖尿病人安排做门诊手术对麻醉医生来说是一个重大的挑战。因为糖稳态的特性，掌握住院病人突然出现的糖尿病处理是需要的，糖尿病人终末器官的损害要被仔细评估。心血管疾病，自律性差和肾功能不全，轻度胃瘫都导致围术期潜在的问题发生。
优先安排胰岛素依赖的糖尿病人在当天的第一或第二台进行手术，主要的原因是避免高血糖，低血糖和酸中毒的发生。没有及时给胰岛素即使是在禁食状态下也会导致酮症酸中毒的发生。因为这个原因，推荐病人到达门诊手术中心后，葡萄糖和胰岛素一起给予。胰岛素皮下或静脉途径均可。持续输注普通胰岛素代替1/3-1/2长效皮下胰岛素的优点还没有得到证实。清早手术的另外一个选择是术后立即皮下给长效胰岛素，并且改变随后的所有进食和胰岛素注射的时间。
仅依靠口服一种降糖药控制血糖的非胰岛素依赖患者术前定期采用简易或实验室法监测血糖是必须的。有些口服降糖药的半衰期可达到60小时（氯磺丙脲）。幸运的是，非胰岛素依赖的糖尿病人很少发生酮症酸中毒，但血糖高时，这些病人可以有高渗性腹泻，非酮症昏迷和脱水。
离院前，糖尿病人能够进食，没有导致呕吐和不能摄入足够热量的恶心发生是非常重要的。
5.What types of surgical procedures are appropriate for ambulatory surgery?
Initially, it was believed that procedures should be limited to those that could be easily accomplished within 1–11/2 hours. This was based on the premise that recovery time would be significantly prolonged after the administration of a lengthy general anesthetic and would perhaps prevent discharge. However, it has been well demonstrated that patients may be discharged safely and on a timely basis even after long operations performed with general anesthesia.
The types of surgical procedures that may be performed on an ambulatory basis will depend on whether an ambulatory surgery facility is truly a freestanding unit (geographically detached from a hospital) or is located within a hospital, or directly contiguous to an inpatient facility. Hospital-based units often accept patients with a greater severity of baseline illness and may perform more complex surgical procedures for a number of reasons. In the event of an unexpected massive surgical hemorrhage, availability of immediate blood bank support is crucial. However, when the need for blood may be anticipated preoperatively, even freestanding ambulatory surgery centers can arrange for blood products to be available, and transfusions may be administered if the need arises. Patients may also be asked to donate one or more units of autologous blood, which may be kept available for either intraoperative or postoperative use. Procedures in which blood might be administered include extensive liposuction or reduction mammoplasty. Radiology services, as well as subspecialty consultative services and the relative ease of hospital transfer for overnight admission, allow performance of more involved and invasive procedures in hospital-based ambulatory surgical facilities.
Ideal procedures for ambulatory surgery result in relatively minor postoperative physiologic changes including fluid shifts and blood loss. Commonly performed surgeries include procedures from all surgical disciplines and subspecialties. A few examples include cataract extraction, minor breast surgery, plastic surgery, dilatation and curettage, hysteroscopy, termination of pregnancy, laparoscopy, arthroscopy, inguinal and umbilical herniorrhaphies. The common denominator of all the procedures is that they are associated with only mild-to-moderate degrees of postoperative pain, which may be readily controlled by oral analgesic agents.
In the early days of ambulatory surgery, tonsillectomy was an example of a procedure that was considered to require overnight in-hospital observation. Today, it is being performed on an ambulatory basis in many centers, although the period of postoperative observation is increased compared with that for other ambulatory surgeries. After tonsillectomy, nausea and vomiting are the most common complications causing morbidity. Early bleeding, if it occurs, usually becomes evident within the first 6 hours. Therefore, it is now considered safe to discharge individuals to home who are otherwise in good health and reside within a reasonable distance from the facility with responsible adults. It is especially important that adequate fluid repletion be accomplished before discharge because early attempts at fluid intake after tonsillectomy may be relatively unsuccessful as a result of marked pharyngeal pain.
5.门诊手术包括的种类有哪些？
可以进行的手术种类包括门诊手术设施是否是真正独立的（地理位置远离医院）或在院内，或直接和住院病人设施相连，有很多原因使院内门诊手术似可以接受比较严重疾病并能开展较复杂的手术。在意外发生大出血时，有可以立即应用的血库支持是非常重要的。实际上，何时需要用血术前应该可以预见，即使是独立的门诊手术也可以与被一些血制品可以使用，当需要时可以立即输血。也可以要求病人进行一个或多个单位的自体血储备，以备术中或术后使用。输血在大量吸脂术或乳房复位成形术也有可能用到。便捷的放射、咨询和转运到住院部过夜治疗，使得院内的门诊手术可以开展更大范围和侵入性操作。
理想的门诊手术是相对小的术后生理学变化，包括体液转移和失血。通常可以施行的手术包括各个学科和亚学科。如卡它性液体抽吸术，较小的乳腺手术，整形外科手术，刮宫术，宫腔镜检查术，终止妊娠，腹腔镜和关节镜检查术，腹股沟疝和脐疝修补术等。所有手术的通常标准是术后仅有轻到重度的疼痛，并且口服镇痛药可以很好控制的手术。
刚开展门诊手术的早期，扁桃体切除术被认为是需要住院过夜观察的例子之一。尽管术后观察的时间较其他门诊手术长，现在有很多中心开展了这种手术。扁桃体切除术后恶心、呕吐是致死的主要原因，早期有出血，通常术后6小时内较明显。因此现在认为让体格较好的病人，距离不远的和家里有负责人的父母的病人离院回家是安全的。离院前充分补液是重要的，因为咽痛早期经口流质摄入相对不安全。
6.What is the appropriate fasting time before ambulatory surgery that necessitates an anesthetic?
The prescribed preoperative fasting period for both fluids and solids for patients scheduled for ambulatory surgical procedures should be identical to that required for an inpatient who is scheduled to receive an anesthetic. The ASA have released guidelines that recommend 8 hours for solids, 6 hours for a light meal (toast and tea), 4 hours for breast milk, and 2 hours for clear liquids. Eight ounces of orange juice without pulp or coffee without milk has not been demonstrated to increase gastric volume. In fact, both resting gastric volume and acidity may be reduced, which may further decrease the incidence and potentially devastating sequelae of an intraoperative aspiration.
Other benefits result from decreasing the fasting time in preoperative patients. Patients allowed to drink clear fluids are more content while they impatiently wait for a surgical procedure that was either delayed or was scheduled for the latter hours of the day. Thirst is relieved, and hunger may be diminished. Furthermore, the ingestion of glucose-containing solutions may also prevent relative degrees of hypoglycemia noted in both healthy patients and those with limited reserves. It is important to emphasize that medications required for the maintenance of homeostasis such as blood pressure and cardiac drugs can be taken orally up to 1 hour before surgery with an ounce of water.
Fasting guidelines should not be made on a case-by-case basis but rather should be reflected in facility- or institution- wide guidelines.
6.门诊手术麻醉合适的禁食时间是多少？
术前禁食时间要靠接受麻醉的时间决定。ASA出版的指南是，推荐8小时禁固体食物，6小时禁易消化食物（土司和茶），4小时禁母乳，2小时禁清水。8盎司不带果肉的橙汁和不加牛奶的咖啡认为不增加胃容量。实际上，他们能使能增加潜在术中误吸的胃容量增加和胃酸都减少。
减少术前禁食时间的其他益处。当手术被推迟或当天晚些时候进行时，病人喝一些含有其他物质的清凉液体有助于减轻等待手术造成的不耐烦。口渴减轻，饥饿感消失。另外，含糖液体的摄入也可以阻止包括健康的和糖储备有限的病人发生低血糖的程度。需要强调的一点就是维持血压和心脏功能的药物可以在术前1小时用1盎司水口服。
接台手术不用给禁食指导，但是在设备简易的地方还是要重视或给予一个范围较宽的指南。
7.Should drugs be administered to empty the stomach or change gastric acidity or volume before the administration of an anesthetic?
Studies regarding differences in the resting gastric volume between the inpatient and ambulatory population have yielded conflicting results. Whereas some anesthesiologists administer liquid antacids before the induction of anesthesia, no evidence supports the notion that every patient must receive a soluble agent (0.3 molar sodium citrate, 30 ml). A soluble antacid is substituted for the conventional nonabsorbable antacid containing aluminum, magnesium, or calcium hydroxide to avoid the severe chemical pneumonitis that may result from aspiration of these particulate substances. Other pharmacologic agents include the H2-receptor blockers (ranitidine or famotidine), which inhibit gastric acid production and decrease gastric volume. Mental confusion has been reported after intravenous administration of cimetidine in geriatric patients. Ranitidine is more potent and specific and has a longer duration of action than cimetidine. Metoclopramide increases the tone of the lower esophageal sphincter as well as facilitating gastric emptying. However, it does not guarantee a stomach free of gastric contents. It also possesses anti-emetic properties. Metoclopramide, in conjunction with an H2-receptor blocker, may be more efficacious. However, the routine use of any of these drugs in patients without specific risk factors is not currently recommended.
Diabetes mellitus with evidence of autonomic dysfunction or gastric atony, documented hiatal hernia, a history of symptomatic gastroesophageal reflux, pregnancy, significant obesity, acute abdomen, or current opioid use or abuse are examples of diseases or conditions that appear to increase the incidence of aspiration during induction or emergence from general anesthesia or during heavy sedation. Therefore, prophylaxis in these situations is recommended. There is no advantage to administration of triple prophylaxis with H2-receptor antagonists, soluble antacids, and metoclopramide. If prophylaxis with an H2-blocker is employed, it should be given 1–2 hours preoperatively. Another effective regimen combines metoclopramide on the morning of surgery and a nonparticulate antacid immediately prior to surgery.
Despite the administration of pharmacologic agents and imposition of fasting, significant amounts of acidic gastric contents may still be present. Fortunately, aspiration of gastric material remains a relatively rare occurrence. If a patient is observed to aspirate and if symptoms of cough, wheeze, or hypoxemia while breathing room air do not develop within 2 hours, the development of significant respiratory sequelae is unlikely. Therefore, reliable and otherwise healthy ambulatory patients can probably be discharged after several hours of observation in the postanesthesia care area with the proviso that they immediately contact their physician at the onset of any symptoms.
7.麻醉前是否使用药物促进胃排空，改变胃液酸度和胃液量？
在住院病人和门诊病人不同研究得到的是相互矛盾的结果。然而，一些麻醉医生诱导前给予抗酸液体，没有证据支持每个病人必须给予易溶药物（0.3mmol柠檬酸钠,30ml）。可溶性抗酸药替代了传统的含铝、镁、氢氧化钙抗酸药，避免了这些颗粒的吸入产生严重化学性肺炎可能。其他一些药物包括H-2受体阻断剂（雷尼替丁或法莫替丁），可以抑制胃酸的分泌减少胃内容物。但是已经有报道老年病人静脉给予西咪替丁后有精神错乱的发生。雷尼替丁较西咪替丁有更强的效能，更高的特异性和更长的作用时间。胃复安促进胃排空的同时可以增加食道下端括约肌张力。但是它也不能保证胃内容物万无一失。也应给予抗呕吐药物。胃复安联合H-2受体阻断剂或许更有效。但是，当前不推荐对不存在特殊风险的每个病人常规使用。
有明确证据的胃自律性差或胃无力，明确资料显示的食道裂孔疝，胃食管返流史，怀孕，肥胖症，急腹症或当前正在使用和滥用阿片类都能增加诱导时，全麻时和深度镇静时无锡的发生率。因此推荐在这些情况下要预防发生。假如给H-2受体阻止剂，就要在术前的1-2小时给。另一个有效的措施是术晨使用胃复安联合术前立即使用非粒子类抗酸药。
尽管给予制酸药和禁食处理，一定数量的胃内酸性内容物是仍然存在的。幸运的是，误吸只是一个相对的发生率。如果病人被观察到有误吸，并且在呼吸室内空气时咳嗽、哮鸣音和低氧血症症状2小时内无进一步加重，发展为严重呼吸疾病的几率较小。因此，健康病人在麻醉后恢复室观察几个小时，并且在保证一旦发生任何症状将和他的医生立即联系后可以考虑让其出院。
8.How can patients be appropriately screened for anesthesia when ambulatory surgery is planned?
In the ideal situation, on the day before surgery a patient having an ambulatory procedure would have the opportunity to participate in a private conference with the anesthesiologist who will be caring for him or her. Rapport and trust could be established, and history and physical assessment could be conducted. Furthermore, appropriate laboratory tests could be ordered and additional consultations, if deemed necessary, could be requested. Finally, information from old medical records could be obtained.
To avoid an additional trip for the patient and family, some facilities may substitute a screening telephone interview for a personal interview, conducted by either a nurse or an anesthesiologist several days before surgery. Pertinent medical history can be elicited, general and specific instructions can be given, and reassurance offered to the patient. In this scenario, laboratory studies and additional components of the data base including an electrocardiogram (ECG) and radiographs, if necessary, are performed immediately before surgery. Previously established criteria will determine the tests that must be obtained. Of course, on the day of surgery the anesthesiologist must still review all information with the patient, conduct the appropriate examination, and obtain informed consent.
The surgeon who schedules surgery must assume a large degree of responsibility for the medical evaluation of the patient. The surgeon is often the only physician to see the patient until the day of surgery. Besides conducting a thorough history and physical examination, the surgeon may also request medical consultation when appropriate.
To aid in the screening process, surgeons may also selectively order laboratory and other examinations according to written guidelines established by the medical facility. However, a mechanism should be in place for free communication between the surgeon’s office and the facility so that appropriate action may be taken when abnormal laboratory values or other reports are received.
The anesthesiologist’s preoperative interview should be conducted in a relaxed, unhurried, and comprehensive manner both chronologically and geographically apart from the operating room. It is highly improper to conduct the preanesthesia interview and examination with the patient stripped of clothing and strapped to the operative room table. At this moment, the patient’s anxiety level may be extraordinarily high. Therefore, the patient may neglect to communicate essential information that may have an impact on either general medical care or intraoperative anesthetic management. Under these circumstances, it is truly impossible to obtain informed consent for anesthesia, which is a moral as well as a legal necessity. Additionally, with the surgeon and nurses waiting and instrumentation prepared, the pressure on the anesthesiologist to proceed with anesthesia may be intense.
The anesthesiologist should not fail to question patients firmly regarding the use of illicit drugs. In one patient population, one quarter of the subjects were found to have positive urine findings for commonly abused substances. Depending on the drug involved, modifications in patient management including cancellation of surgery might be well advised. Additionally, users of illicit drugs may have diminished capability or interest in complying with postoperative instructions.
8.怎么适当拒绝对已经安排门诊手术的病人进行麻醉？
理想的情况下，病人术前某天会有一个和他的麻醉医生会面的机会。进行沟通和建立信任，并进行病史和身体条件评估。另外还要开出一些实验室检查项目，如果认为有必要还可以对一些疑问进行咨询。最后从以往的医疗文件得到一些信息。
为了避免病人和家属的来回奔波，也可以用可视电话会面，可以由护士或麻醉医生在术前几天进行。这可以得到以前的医疗病史，也可以给出总的和特殊的指导以及一些安全承诺。这种方案下，如果觉得必要术前要可立即进行实验室检查和附加的资料库包括心电图（ECG），X光。之前的实验标准要得到。当然，手术当天麻醉医生要回顾所有的病人信息，作适当的检查，并得到病人的同意。
安排手术的医生必须对病人的医疗评估负起责任。通常直到术前一天手术医生是仅仅见过病人的唯一医生。除外完整的病史和体格检查，手术医生也担负起咨询的任务。
为了过程的完整，外科医生会按照医疗文书的指导进行一些实验室和其他的检查。实际上应该有建立一种机制，在当实验室和其他检查出现异常时，让病人和医生在医生办公室和手术室进行充分的交流。
麻醉医生术前访视应该在一个宽松的，放松的，关怀的环境中进行。病人脱光衣服在手术检查床进行麻醉访视和检查认为是非常不合适的。因此病人会忽视必要的交流，这将影响总体药物疗效和术中麻醉的管理。在这种环境中，真的不可能得到进行麻醉的同意，这在法律上也是正常的。另外，外科医生和护士的等待以及器械的准备对麻醉医生实施麻醉造成的压力也很大。
这种情况下，麻醉医生会漏问使用违禁药物的问题。病人中，有1/4会因为滥用普通药物而尿检呈阳性。依据使用的药物对病人作出适当的处理，包括建议取消手术。另外使用违禁药物的病人对术后指导的遵从度和执行的兴趣都减低。
9.What preoperative laboratory studies should be obtained before surgery?
For an ambulatory surgery unit that is affiliated with or attached to a hospital, clinical laboratory testing guidelines should be identical to those required by the related institution. It has been well established that shotgun, nonselective screening batteries of both laboratory, radiographic, and other studies yield an extraordinarily low rate of abnormal findings, few of which may have a significant impact on patient management. Patients scheduled for surgery should have preoperative testing ordered with selectivity and based only on a screening including a careful history and physical examination. In fact, indiscriminate ordering of tests can have potentially serious and deleterious consequences. To explain abnormal results, additional series of tests may be obtained. Some invasive studies have inherent dangers. Often, abnormalities are simply ignored, creating a potential medicolegal liability. Indiscriminate screening often reveals abnormalities that fail to have any relevance to either the surgery or the choice of anesthetic agent or technique. Some centers use handheld computers to obtain the patient history. Branching lines of questioning dependent on previous answers allow extensive information to be gathered. At the conclusion of the interactive interview, the computer can provide a detailed printout of significant findings in the history and recommend the preoperative testing to be obtained. Many facilities do not require any preoperative testing for superficial surgical procedures on otherwise healthy men and women below the age of 40–50 years.
9.术前需要知道那些实验室检查结果？
对于附属的或靠近医院的门诊手术室，要达到临床检查指导标准。他们建立了shotgun、一系列的实验室、放射学和其他检查异常情况漏诊的几率非常小，几乎不会影响到对病人的管理。被安排手术的病人按照择期手术的要求进行术前检查，依照规定包括一个详细的病史和体格检查。实际上，繁杂的检查会带来潜在的严重和有害后果。为了解释异常的检查结果，就需要另外一系列的检查。一些侵入性检查有潜在的危险。一般异常结果如果被简单的忽视，会有潜在的医学法理责任。繁杂的检查往往会发现不正常的结果，导致不能进行任何手术选择，麻醉药物选择和麻醉操作。一些中心用手提电脑采集病史。依赖病人回答得到的各种问题分类列表可以得到广泛的信息。交互式访问的结果，电脑会提供一份详细的有关病史和推荐术前要做检查的详细报告。一些机构对健康男性和40-50岁以下女性的表浅手术部要求进行任何检查。
10.Should an internist evaluate each patient before ambulatory surgery?
The same rules and standards regarding a complete preoperative evaluation of patients apply to surgery scheduled on either an inpatient or an ambulatory basis. Accordingly, an internist or medical subspecialist should be consulted regarding the advisability of surgery at a particular moment in time whenever the stability of a patient’s medical condition is questionable. Although it may be true that the resultant physiologic perturbations associated with some ambulatory surgery procedures may be characterized as minor, there is nothing minor about the administration of an anesthetic. A complete written history and physical examination are required as part of the medical record before the administration of anesthesia and commencement of surgery. For patients with no or stable co-existing medical conditions, the complete history and physical can be done by the surgeon. However, for patients with significant co-existing medical diseases and/or whose medical status may be questionable, there should be an evaluation completed by the internist or medical subspecialist.
10.每个门诊手术病人都要进行内科医师评估吗？
不论是住院或门诊准备手术病人都执行术前相同的规则和标准进行评估。一般无论任何时候病人的医疗状况有问题时，都要进行内科和专科医生会诊。有小手术，但是没有小麻醉。对于没有或有稳定疾病状态的，由外科医生写出完整的病史和体格检查。对明显伴有其他疾病和医疗状况不稳定时，需要由内科医生和专科医生作出完整的评估。
11.Is anxiolytic premedication advisable before ambulatory surgery, and what agents are appropriate?
Because the goal of anesthesia for ambulatory surgery is to permit early discharge to home, there was concern that the administration of short-acting anxiolytic or analgesic premedication might delay recovery from anesthesia and thereby prolong time in the postanesthesia care unit (PACU) with a resultant delay in patient discharge. However, no significant differences in recovery times can be demonstrated after short-acting premedicants have been administered. The effects of more potent and longer-acting anesthetics and the surgical procedure itself contribute in a more significant fashion to the recovery time before a patient may be discharged. However, although time to discharge, a gross measurement, may remain unaffected, tasks that require fine coordination and speedy reaction times may still be deleteriously affected.
Many patients experience anxiety in the immediate preoperative period, and pharmacologic management is quite acceptable. The administration of either diazepam, 5–10 mg orally, 1–2 hours before surgery or midazolam, 1–2 mg intravenously, after an intravenous catheter is placed before surgery can ameliorate distress if deemed desirable. The amnestic effect of intravenous midazolam is powerful, and patients may not remember having seen their surgeon. Midazolam can also be given orally, although much larger doses are required because of first-pass hepatic degradation (0.5–1 mg/kg orally). Opioid premedication may contribute to the incidence of postoperative nausea and vomiting.
Preoperative oral doses of clonidine, a centrally acting a2-adrenergic agonist have been used to provide sedation, reduce anesthetic requirements, and decrease episodes of hypertension and tachycardia during intubation and maintenance of anesthesia. Side-effects of this class of drugs may include dryness of the oral cavity, hypotension, as well as undesirable sedation extending into the postoperative period. Relaxation techniques have been taught preoperatively to patients and may aid in the reduction of anxiety level. Instruction of these techniques, however, is time-consuming and requires patient motivation, and is therefore usually reserved for selected patients with extreme phobias.
11.门诊手术前建议给抗焦虑药吗？哪些药物合适呢？
因为门诊手术麻醉的目标是早期让病人离院回家，所以关注所给的短效抗焦虑和镇痛药可能会延长麻醉恢复时间和在麻醉后恢复室（PACU）观察的时间，耽搁病人离院。而实际，没有资料证明术前给短效药物对恢复时间的影响有显著差异。长效强效麻醉药物和手术本身更能影响到病人达到离院的恢复时间。而实际，虽然对病人离院前的粗略评估可能没有影响，但是对指令性运动和快速反应时间还是有影响的。
大多病人在术前刻都存在焦虑状态，因此术前给药是被广泛接受的。如果需要术前1-2小时口服5-10mg地西泮或建立静脉通道后静脉1-2mg咪唑安定可以减轻不适。咪唑安定顺行性遗忘作用很有用，病人可以不能回忆已经见到的手术医生。咪唑安定可以口服，但是因为首过效应需要的量较大（05-1mg/kg）。预给阿片类药物可以减轻术后发生的恶心呕吐。
术前口服剂量的可乐定，一种证明有镇静作用的中枢α2受体激动剂，可以减少麻醉药量和预防插管和维持过程中高血压和心动过速的发生。这类药的副作用还有口腔干，低血压和不希望发生的术后长时间镇静。术前放松技术的指导有助于帮助病人减轻焦虑水平。实际上，这些技术的指导，需要消耗时间和需要病人的配合，因此通常只对那些有特别恐怖的病人进行。
12.What are the reasons for last-minute cancellation or postponement of surgery?
The incidence of last-minute postponement or cancellation of ambulatory procedures exceeds the cancellation rate for the inpatient population. A multiplicity of factors can be operative. Repeat physical examination by the surgeon may reveal the disappearance of pathology. Patients may forget and ingest either solid food or liquids before arrival at the medical facility. Abnormal results on tests that were not available or not previously reviewed may be discovered. Communication between the surgeon and anesthesiologist regarding laboratory abnormalities will help to reduce the incidence of last-minute cancellation of surgery, the consequences of which distress both patient and surgeon and make for inefficient use of available operating room time. Additional questioning may reveal either new symptoms or significant history that was not previously elicited. Physical findings apparent on a last-minute assessment by the anesthesiologist may preclude the safe administration of an anesthetic. Examples include an acute upper respiratory tract infection or an exacerbation of bronchospastic pulmonary disease. Finally, patients may arrive late to the facility or without a responsible escort to accompany them home.
Because the escort’s function in the postoperative period goes beyond merely ensuring a safe means of transportation home, in the absence of a designated appropriate escort, surgery should not proceed unless alternative care arrangements are made. If the patient speaks only a foreign language, the escort may serve as an interpreter throughout the perioperative period. After surgery, the escort will receive the postoperative instructions and serve as a companion to the patient during the first 24 hours following the completion of surgery. Assistance in the performance of activities of daily living will be rendered as required. Additionally, the escort will be available to summon medical assistance in the event of a medical, surgical, or anesthetic complication.
12.最后一刻取消或推迟手术的原因？
门诊病人最后一刻取消或推迟手术的机率高于住院病人。有很多原因，如外科医生再次检查发现病理学变化的消失，病人因为忘记在来到医院前有固体或流质饮食，用处不大的或之前没有发现的异常检查结果。外科医生和麻醉医生对异常检查结果的交流有助于减少最后一刻取消手术的发生，最后一刻取消手术会使外科医生及病人感觉到郁闷，并且不能充分利用手术时间。另外的问题还有新出现的症状或之前没有引出的病史，最后一刻麻醉医生作出的评估体检认为麻醉不安全，如急性上呼吸道感染或支气管肺部疾病的恶化。也可能因为迟到或没有可以负责任的护送人员陪伴而取消。
因为护送人员不仅仅是简单的在术后把病人安全的转运回家，在没有制定的护送人员时，手术不能进行，除非已经做好护理安排。如果病人只会讲外语，护送人员从术前期就可以充当翻译，术后护送人员将接受术后指导并且在术后的第一个24小时专职陪伴，护送人员还可以进行普通的医疗辅助如医疗，手术或麻醉并发症等。
13.What is the ideal anesthetic for ambulatory surgery?
No single anesthetic is ideal for every procedure performed. However, the goal of the anesthetic is to allow for patient discharge shortly after the procedure’s completion. An ideal general anesthetic agent would have a rapid onset, permit a rapid return to baseline levels of lucidity and equilibrium, and be free of deleterious cardiovascular and respiratory effects. It would provide intraoperative amnesia, analgesia, and muscle relaxation and would possess anti-nausea and anti-emetic properties. Unfortunately, such a marvelous single agent is not in existence at the present time. In an attempt to avoid some of the unpleasant side-effects associated with general anesthesia, regional anesthetic techniques including field blocks, intravenous regional block (Bier block), various approaches to the brachial plexus, ankle block, and spinal and epidural anesthesia have been offered to patients as an alternative to general anesthesia.
13.什么是门诊手术的理想麻醉？
没有一种麻醉药对所有手术都理想。这种麻醉的特点就是允许病人术后早期离开。一种理想的麻醉药将是快速起效，快速恢复到术前的清醒和平静水平，并且无有害的心血管和呼吸功能影响。它能提供术中的遗忘、镇痛、肌松，并且拥有显著的抗恶心呕吐特性。不幸的是，到现在仍然没有一种这么神奇的药物存在。为了避免全麻带来的不愉快的副作用，区域阻滞技术包括部位阻滞，静脉区域阻滞，各种入路的臂丛阻滞，踝部阻滞和硬膜外阻滞都用来替代全麻。
14.Are there relative or absolute contraindications to the administration of a general anesthetic in the ambulatory setting?
Sometimes the administration of a general anesthetic clearly should be avoided, if possible. Examples of such cases are a patient with severe, poorly controlled asthma or documented bullous emphysema. In these cases, lesser concern should be given to the possibility of a postdural puncture headache (PDPH) if more serious sequelae are likely to result during or after administration of a general anesthetic. This, however, is the exception rather than the rule, and in most instances the final choice of anesthesia should remain with the patient, guided, of course, by the anesthesiologist. Additionally, when a patient arrives for extremely minor surgery without an escort, a local anesthetic injection alone might suffice for anesthesia. This might allow the patient to return home unaccompanied. Unfortunately, it sometimes becomes necessary to supplement a local anesthetic with intravenous sedation, and under these circumstances an escort would then be mandatory.
14.有没有门诊手术给全麻药的相对或绝对禁忌证？
可能情况下，应尽量避免给予全麻药。例如有一个严重的控制较差的消除病人或一个有明确资料证明大泡型肺气肿病人，这种情况下主要不是考虑硬膜外穿刺后头疼（PDPH）的问题更需要考虑的全麻中或全麻后的管理问题。而这是个规则的例外，大部分情况下最终的选择权应该留给病人，当然要在麻醉医生的指导下。另外，当一个病人只需要做一个非常小的手术并且没有陪护人员时，局麻药注射就足够了。可以不要人陪护直接回到家里。不幸的是，有必要静脉给予镇静药来补充。这种情况下陪护人员是必须的。
15.What are the advantages and disadvantages to performing a conduction anesthetic in the ambulatory patient?
Employing regional anesthesia in the ambulatory surgery patient has a number of potential advantages. If little or no intraoperative sedation is required, little or none of the “hangover” effect will be present throughout the postoperative period. Patients who express fear about losing consciousness or the loss of control associated with a general anesthetic may prefer a regional technique. Some patients have a strong desire to remain awake to view arthroscopic surgery as it is being performed.
Spinal or epidural anesthesia, however, has potential disadvantages. There had been concern regarding the apparent increased incidence of PDPH in patients who ambulate postoperatively. However, experience has shown that the incidence of PDPH is equal among patients who are nonambulatory and ambulatory, but that the onset may be delayed in patients who remain recumbent for a longer period of time. If spinal anesthesia is chosen, the use of conventional smaller gauge needles as well as newer designs (Greene, Sprotte, Whitacre) that include modifications at the tip to be less traumatic appear to markedly reduce the incidence of PDPH. The theory behind the pencil-point Greene, the conical Sprotte, or side port Whitacre needles is that splitting rather than cutting of the dural fibers occurs, which may reduce the amount of cerebrospinal fluid (CSF) leak.
Reduction of the incidence of PDPH to approximately 1–2% or less would be an ideal goal. Technical failure rates of the various needles must also be figured into the overall equation.
Patients must always be informed regarding the potential for development of a PDPH because ambulatory patients usually expect to resume their normal activities shortly after surgery. Additional recommendations to reduce the incidence of headache include keeping the bevel edge of the conventional needle parallel to the longitudinal axis of the body and the dural fibers and avoiding multiple attempts at subarachnoid needle placement. Maintenance of adequate hydration intraoperatively and postoperatively and avoiding straining and lifting postoperatively are recommended.
Patients presenting with a persistent PDPH may require an epidural blood patch for relief. Therefore, it is especially important to follow up patients with a telephone call at 24–48 hours after surgery to inquire about the presence of any problems. Conservative treatment of a PDPH in the ambulatory patient includes traditional analgesics, fluids, and bed rest. Performance of an epidural blood patch should be considered early if the headache is perceived by the patient to be extraordinarily severe or incapacitating, or if the patient must return to work immediately, or care for children.
In an attempt to avoid the possibility of a PDPH in younger patients, an epidural anesthetic may be offered to patients if a regional technique is requested or medically indicated. Though an epidural requires greater technical expertise and may be slightly more time-consuming to perform when compared with a spinal, the insertion of a catheter allows additional incremental doses of anesthetic to be added if surgical time is unexpectedly lengthened. Additionally, the use of shorter-acting local anesthetics allows for timing the block to wear off shortly after the procedure is completed. However, the incidence of headache after unintended dural puncture with larger gauge epidural needles is significantly higher. It is interesting that the reported incidence of headache following a general anesthetic in ambulatory patients exceeds the incidence of headache after regional anesthesia, although it is usually much less incapacitating and is self-limiting. It is postulated that the cause of the headache is intraoperative and postoperative starvation and an element of dehydration.
Spinal anesthesia provided by tetracaine and bupivacaine has been associated with recovery room stays as long as 6–8 hours. This must be considered before performing a regional anesthetic, especially if the procedure is to be done later in the day. Another potential disadvantage of administering a spinal anesthetic in an ambulatory patient is the potential for persistence of autonomic blockade for 1–2 hours following restoration of motor function. This can result in the inability to urinate and the need for bladder catheterization. It appears that increasing duration of sympathetic blockade correlates with an increased incidence of urinary retention.
15.对门诊手术施行部位麻醉的优缺点？
对门诊病人施行区域阻滞有很多潜在的优点。如果术中镇静药需要非常少或根本不需要，术后将无或有很轻微的宿醉感。对全麻后失去知觉或控制担心的病人愿意选择区域阻滞技术。有一些关节镜手术病人强烈希望能保持清醒观看手书操作。
椎管内麻醉存在潜在的缺点。有担心门诊手术后PDPH发生率增加。而实际，经验显示门诊病人和非门诊病人PDPH的发生率相等，但是较长时间的卧床将会延迟PDPH的出现时间。如果选择蛛网膜下腔阻滞，使用比传统型号较小的或新型设计的（Greene, Sprotte, Whitacre）包括尖端改进可以减少创伤的穿刺针可以显著减少PDPH发生率。铅笔尖后的Greene理论，圆锥形的Sprotte针或侧面缺口的Whitacre针都可以减少脑脊液（CSF）的外漏。
PDPH的发生率可以减少大约1-2%的发生率，远没有达到理想的目标。各种针使用发生的失败率也要计算在内。
病人术前必须被告知有发生PDPH的可能，因为门诊手术病人通常希望术后短期恢复他们的正常活动，另外为减少PDPH推荐穿刺时保持针斜面平行身体长轴和硬膜外纤维走形，避免多次尝试穿入蛛网膜下腔。推荐保持术中、术后足够的体液，避免术后劳累和lifting。
有持续PDPH的病人需要进行硬膜外血斑治疗。因此在术后24-28小时电话询问存在的任何问题很重要。门诊手术病人PDPH的保守治疗包括传统的镇痛、补液和卧床休息。采用硬膜外血斑治疗应考虑到病人是否有严重的或不能忍受的头疼，或病人必须立即回到工作岗位，或需要照顾孩子。
为了避免年轻病人发生PDPH的可能，如果区域阻滞需要或有指征，可以采用硬膜外麻醉。尽管硬膜外需要一个较好的技术专家并且较腰麻花费更多的时间，置入的硬膜外导管可以追加局麻药来满足意外的手术时间延长。另外，短效局麻药的使用可以在手术结束短时间内阻滞作用消退。但是用硬膜外针穿破硬膜后术后头疼的发生率显著增加。有趣的是有报道门诊手术病人全麻后头痛的发生率超过了部位麻醉，尽管这种疼痛很少是不能忍受的和自限的。有假说认为它是因为术中和术后的饥饿和脱水造成的。
用丁卡因和布比卡因进行蛛网膜下腔麻醉需要在恢复室停留6-8小时。这在实施区域麻醉前必须要考虑到，尤其是在当天晚些时候进行的手术。另一个不利因素是运动功能恢复后自主神经阻滞还要维持1-2小时，这可能导致尿潴留而需要插尿管。表明交感神经阻滞时间的增加和尿潴留发生率的增加有关。
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16.What are the advantages and disadvantages of selecting a nerve block technique for the ambulatory patient?
There are numerous advantages to selecting a nerve block technique when the type of surgery permits. The ability to continue profound analgesia into the postoperative period provides for patient comfort, which may allow early return home from the facility. However, rapid return to presurgical levels of mental alertness and acuity can be achieved only if judicious amounts of sedative drugs are administered during both performance of the block and surgery. Patients may have a decreased incidence of nausea in the early postoperative period if smaller amounts of intravenous opioids are required or can be avoided entirely. This may also allow earlier alimentation and a speedier return to normal functioning.
There are a few disadvantages to performing nerve blocks in the ambulatory surgical patient. Preparation and performance of a block anesthetic may require more time than the induction of a general anesthetic. In some instances, the actual performance of a regional block and establishment of surgical anesthesia may take longer than the proposed operation. Brachial plexus and other nerve blocks have a known failure rate, and incomplete or inadequate anesthesia will further delay the onset of surgery. Some patients will not tolerate any sensation whatsoever and may require inordinately large amounts of sedative drugs throughout the procedure. This might easily negate some of the advantages of selecting a regional approach.
Unfortunately, patients who have not been seen by an anesthesiologist before the actual day of surgery and arrive with the expectation of receiving a general anesthetic may be unprepared to accept another technique. The surgeon’s preference will also influence the receptiveness of a patient to a regional technique. A surgeon who prefers the use of major conduction anesthesia or nerve blocks will often inform patients of the benefits and availability of these techniques during a preoperative discussion of the proposed surgery.
16.对门诊手术选择神经阻滞的优缺点？
手术允许时采用神经阻滞麻醉有很多优点。提供病人感到舒适的术后完全镇痛可以使病人早期回家。事实上，如果麻醉和手术时给予适量的镇静药病人可以很快恢复到数前的灵敏度和精细的分辨力。如果静脉给予小剂量的阿片类药物可以降低术后早期的恶心发生率，甚至完全避免。这有助于允许早期进食快速恢复正常功能。
门诊手术病人应用神经阻滞也有几个缺点。神经阻滞准备需要的时间较全麻诱导需要更多的时间。某些情况下区域麻醉和外科麻醉花费的时间较手术本身还要长。都知道臂丛和其他一些神经阻滞存在一定的失败率，阻滞不全或深度不够都进一步延迟手术开始的时间。一些病人耐量较大，整个过程需要给予较大剂量的镇静药物。这很容易成为否定选择区域麻醉的优点。
不幸的是，到手术当天还没有见过麻醉医生的病人如果是期待采用全麻会导致恨很难接受其他麻醉方法。外科医生的偏爱也影响病人接受神经阻滞。准备使用部位麻醉或神经阻滞的外科医生会在术前讨论中向病人介绍它的好处和实用性。
17.Describe the intravenous regional anesthetic technique (Bier block) for surgery on the extremities.
The intravenous regional anesthetic (Bier block) is an easily performed and extremely predictable method for providing anesthesia of the extremities. It is best reserved for procedures on the upper extremity below the elbow, although it can provide anesthesia for surgery on the distal lower extremity as well. The technique of intravenous regional block requires little technical skill other than the placement of an additional intravenous catheter in the hand or foot of the extremity to be anesthetized. The block has a rapid onset, and the success rate approaches 100% in most hands. Only minor patient discomfort occurs during performance of the block. After the arm is exsanguinated, by wrapping it in an Esmarch bandage, the tourniquet is inflated to 100 mmHg over systolic pressure, and the elastic bandage is then removed. Fifty milliliters of 0.5% preservative-free lidocaine is then injected through the previously placed intravenous catheter. Surgical anesthesia is achieved within approximately 10 minutes.
Because a significant proportion of the infused medication may enter the systemic circulation, the anesthesiologist must remain vigilant at all times for the development of subtle central nervous system changes. Frank seizures may occur if the tourniquet fails shortly after the drug is injected.
Usually, little or no intraoperative sedation or adjunctive analgesia is required. On release of the tourniquet, anesthesia rapidly dissipates. Therefore, the Bier block is recommended where postoperative surgical pain is apt to be minimal. It is ideal for procedures such as ganglion excision, trigger finger repair, removal of foreign bodies, and carpal tunnel release.
17.描述四肢手术的静脉区域麻醉技术。
静脉区域麻醉（Bier block）易于施行并且在四肢手术易于达到预期的效果。对肘关节以下的手术非常适用，同样对于下肢远端的手术效果同样好。它需要很少的技术要求，不过是在需要手术四肢远端的区域放置一个静脉针而已。它起效快，大部分手外科手术效果100%。整个过程中只有很小的不适出现。在手臂用弹力绷带驱血后，止血带打到100mmHg超过动脉血压，并且去处弹力绷带。从之前放置的静脉针注入50ml 0.5%的利多卡因，约10分钟后可以开始手术。
因为输入药物有相当的部分要进入血液循环，麻醉医生必须对中枢神经系统的改变时刻保持警惕。如果给药后止血带效果不好，可以造成惊厥。
通常不需要辅助或仅需辅助少量的镇静药，松开止血带后，麻醉作用迅速消失。因此，Bier block推荐用于术后疼痛较小的手术。用于神经节切除，扳机指修复，异物取出和腕管松解很理想。
18.What sedatives can be administered to supplement a regional anesthetic?
The best anxiolytic may be a solid relationship between the anesthesiologist and patient; however, excellent rapport may be difficult to establish within the confines of a fast-paced ambulatory surgery center. It has been shown that a preoperative visit with the anesthesiologist immediately before surgery may serve as a powerful anxiolytic itself.
In the pharmacologic realm, intravenous midazolam has proven to have excellent sedative and anxiolytic properties (Table 77.1). It is water-soluble, nonirritating to veins, painless on administration, provides superb amnesia with rapid onset, and it is therefore well accepted by patients. Diazepam can cause significant discomfort on intravenous infusion, and if patients are followed for a number of days after injection it has been shown to cause thrombophlebitis in a significant number of cases. Therefore, intravenous diazepam has been virtually eliminated from the practice of anesthesia. Compared with diazepam, midazolam’s much shorter elimination half-life of 1–4 hours provides a significantly shorter time to recovery. Midazolam is best titrated every 2 minutes in 1- to 2-mg increments, because its onset is rapid and effects may be profound. Sedation after small-to-moderate intravenous doses usually lasts approximately 20–30 minutes. The profound amnestic properties may interfere with assimilating and following instructions, and patients may become unable to cooperate during surgery. Some patients who receive the drug may become completely disoriented, uncooperative, or even combative. This may necessitate either increasing the depth of sedation, pharmacologic reversal, or conversion to a general anesthetic.
Remifentanil is an excellent addition for the patient who requires a short-acting opioid to provide analgesia either during the performance of a painful block or to provide adjunctive analgesia during an inadequate block. It can be administered by intravenous bolus or by continuous infusion. Bolus doses of 0.5 mg/kg may be administered with repeat doses titrated to desired effect. For a continuous infusion, the dose ranges from 0.02 to 0.3 µg/kg/min. Side-effects common to all drugs in the opioid class include nausea, vomiting, and the potential for significant respiratory depression. Alternatively, fentanyl administered in intravenous bolus doses of 25–50 mg can be employed to provide adjunctive analgesia. Instead of using a benzodiazepine to provide sedation, propofol can be administered by either bolus dose (10–20 mg) or continuous infusion (0.1–0.2 mg/kg/min) and titrated to the desired hypnotic effect. Inherent anti-nausea and anti-emetic properties of propofol provide a significant advantage in the ambulatory setting.
18.哪些镇静药可以强化区域麻醉？
麻醉医生和病人之间稳固的信任关系是最好的抗焦虑药；但是这样的关系很难在门诊手术中心快速建立起来。经验显示，术前一刻麻醉医生的访视本身就是一副强有力的镇静药。
从药理学来说，静脉咪唑安定证明有很好的抗焦虑特性（表77.1）。它是水溶性的，对血管无刺激，给药时无痛，起效快并且有良好遗忘作用，因此也容易被病人接受。地西泮静脉注射时有显著的不适感，如果连续几天注射，有很多病例产生了静脉血栓。因此，静脉地西泮被排除在实际麻醉应用之外。相对于地西泮，咪唑安定的消除半衰期1-4小时相对较短，使恢复时间变的较短。因为它起效较快并且效果确切，静滴给药每2分钟可增加1-2mg。但确切的遗忘作用会干扰病人进行合作并听从指导，因此术中可能变的不合作。一些用过药后的病人可能变得毫无判断力，完全不能合作，甚至好斗。这时有必要加深镇静或进行药理学拮抗，或改为全麻。
瑞芬太尼是在还存在有疼痛的神经阻滞或神经阻滞不全需要追加镇痛时病人需要给短效阿片类药物时的较好选择。可以静脉负荷量给药或持续输注，静脉负荷量0.5 mg/kg，然后重复这个剂量会达到预期效果。如果静滴时剂量范围0.02-0.3µg/kg/min。副作用和所有阿片类药物一样包括恶心、呕吐、潜在的呼吸抑制。另外的一种选择，芬太尼负荷量25-50mg也能提供附加镇痛。除去苯二氮卓类，异丙酚静脉10-20mg/次或0.1–0.2 mg/kg/min持续输入也可以达到预期的催眠效果。异丙酚本身具有的抗恶心呕吐的特性是门诊应用的很好优点。
19.What complications of nerve block anesthesia are of special concern to the ambulatory patient?
The potential for pneumothorax must be considered when performing approaches to the brachial plexus other than the more commonly practiced and inherently safer axillary approach (supraclavicular, infraclavicular, and interscalene). This complication may necessitate placement of a chest tube or prolonged observation. The occurrence of central nervous system toxicity ranging from tinnitus to frank seizures secondary to an intravascular injection during an attempted block may delay the onset of surgery but should not prevent eventual discharge from the PACU on the day of surgery. General anesthesia, rather than a repeat block, should be induced after it has been determined that the patient has fully recovered neurologically and after this has been documented on the anesthesia record.
19.门诊手术进行神经阻滞麻醉需要特别关注的并发症是什么？
当在腋前线进行臂丛麻醉时，除了实际的操作和相对安全入路的选择（锁骨上、锁骨下、肌间沟）外必须要考虑到可能会有气胸的发生。这种情况下必须胸腔置管或作留置观察。进行阻滞时误入血管会有从耳鸣到惊厥各种中枢神经系统毒性的表现，它可能会延迟手术开始的时间，但一般不会影响手术当天离开PACU的时间。反复穿刺失败的另外选择是全麻，在确认病人神经功能可以完全恢复后可以实施，但要有相应的麻醉记录。
20.Should patients having ambulatory surgery be tracheally intubated?
Whether ambulatory patients have increased gastric volumes when compared with inpatients scheduled for surgery is now questionable. In view of the small incidence of documented aspiration with subsequent major pulmonary derangements in previously healthy patients presenting for elective surgery, routine tracheal intubation of every patient is not required. Tracheal intubation should be reserved for patients with any of the known risk factors that predispose patients to esophageal reflux or increased resting gastric volume. Of course, if the surgical procedure requires that the airway must be shared with the surgeon or where an airway cannot be easily or safely maintained using an oropharyngeal or nasopharyngeal airway, tracheal intubation should be performed.
The laryngeal mask airway (LMA), approved by the Food and Drug Administration (FDA) for use in 1991, has proven its value in both the inpatient and ambulatory surgery settings. It is presently manufactured in five sizes and is appropriate for the adult patient as well as the neonate. After induction of general anesthesia, the LMA is inserted blindly into the pharynx. Deep anesthesia is necessary for placement of the device. After inflation of the cuff, formation of a low-pressure seal allows both positive pressure as well as spontaneous ventilation. After recovery of normal reflexes, and when the patient is able to respond to commands and open the mouth, the device can be gently removed from the oral pharynx.
When properly placed, the LMA can free both hands of the anesthesiologist for other tasks including proper maintenance of the anesthetic record, adjustment of monitors, and other responsibilities. The incidence of sore throat following LMA use is less than that associated with tracheal intubation. Because muscle relaxants are not required for the insertion of the instrument, postoperative myalgias associated with the administration of succinylcholine can be avoided. Additionally, ocular and oral trauma associated with conventional facemasks and oral airways may be avoided. Edentulous patients, characteristically more difficult to ventilate by facemask, can be managed well with this device. Because the LMA does not interfere with the functioning of the larynx and glottic closure, an effective cough is possible with the airway in place.
Aspiration of gastric contents has been reported in conjunction with this device. It does not guarantee airway protection. However, in the event of a difficult airway where a patient cannot be intubated and facemask ventilation proves to be inadequate, the LMA may serve as a temporizing measure. Contraindications include oral pathology, pulmonary disease marked by low compliance, inability to open the mouth adequately, and conditions that may predispose the patient to gastric reflux.
20.门诊麻醉需要气管插管吗？
是否门诊较住院手术病人胃容量有增加仍有争议。考虑到之前健康病人误吸和随后肺病的发生率较小，不要求对每个病人常规插管。但对食管返流或饱胃等存在公认风险因素的病人应该做插管准备备用。当然，如果手术需要共用气道或口咽通气道或鼻咽通气道不能保证气道安全时需要插管。
喉罩（LMA）从1991年得到美国FDA批准在临床使用以来，它的价值在住院和门诊手术病人都得到了证明。目前有从新生儿到成人适用的5种型号。全麻诱导后盲插入咽部。放置时要有较深的麻醉，充气后形成的低压封闭可以进行正压通气和自主呼吸。正常反射恢复后，病人能做指令性运动和张口时，可以轻轻的从口咽部取出。
正确放好LMA后，麻醉医生可以腾出双手进行其他工作，包括完整的麻醉记录，监护仪的调整和其他相关工作。使用LMA后咽痛的发生率低于气管插管。放置喉罩时不需要肌松，所以司可林相关的术后肌痛也可以避免。另外应用常规面罩和经口气道造成的眼、口部创伤也可以避免。无牙齿病人很难用面罩进行通气，也可以采LMA处理，因为LMA不干扰喉头和声门功能，放置后还可以进行有效的咳嗽。
有使用后发生误吸的报道。LMA应用不能提供完整的气道保护。事实上证明，对插不进管和不能行面罩通气的困难气道病人应用LMA通气是不够的，它只是一种姑息措施。禁忌症包括口腔病变，有顺应性降低的肺部疾病，开口度较小，和预计可能发生胃返流的病人。
21.What is the role of propofol in ambulatory surgery?
Propofol may be used to provide sedation during a regional anesthetic, to induce general anesthesia, and to maintain general anesthesia. It is a water-insoluble, highly protein bound, lipophilic compound that has unique pharmacokinetic characteristics that render it ideal for use with ambulatory surgery. It is rapidly redistributed, and hepatic and extrahepatic clearance (pulmonary) permit rapid recovery of cognitive function with less postoperative sedation and drowsiness compared with the traditionally employed ultra-short-acting barbiturates. Depressant effects on the central nervous system are dose-dependent and range from mild sedation to sleep and unconsciousness. Neither retrograde nor anterograde amnesia is associated with this drug. For the induction of anesthesia, propofol can be administered as a bolus dose (2–2.5 mg/kg slowly), and its effect can be maintained via a continuous intravenous infusion (0.1–0.2 mg/kg/min). Dosages are reduced for debilitated patients and for the geriatric population. For sedation during regional anesthesia, incremental doses of 10–20 mg (0.3 mg/kg) may be given, or an infusion begun. There isa known relationship between propofol (as well as other intravenous agents) serum drug levels and therapeutic effects. For propofol, the target concentration is between 3 and 6 mg/ml to provide surgical anesthesia.
When administered as the sole agent, propofol may not provide amnesia 100% of the time, and intraoperative awareness has been reported. Therefore, it is often used in conjunction with nitrous oxide, a volatile anesthetic, or midazolam. Propofol has no muscle relaxant or analgesic properties. For total intravenous anesthesia, a continuous infusion of a short-acting opioid, such as remifentanil, can be administered along with an infusion of propofol. Additional bolus doses of propofol can be infused to rapidly deepen the level of anesthesia. Another major advantage of propofol appears to be a significantly diminished incidence of postoperative nausea and vomiting. Propofol’s inherent anti-emetic properties allow earlier discharge of patients, even when emesis occurs in the PACU. When used for both induction and maintenance of anesthesia in cases lasting approximately 1 hour, faster recovery time is noted when compared with a thiopental induction followed by maintenance with isoflurane and nitrous oxide. Patients anesthetized with propofol appear to awaken with a positive mood, and they regain equilibrium including the ability to ambulate early. The requirement for pain medication in the postoperative period appears to be reduced, which may be related to an overall feeling of well-being.
Two disadvantages of propofol include the lack of analgesic properties and pain on injection. As for the former, the combination of propofol with an opioid, such as remifentanil or fentanyl, will provide required analgesia. The discomfort associated with administration can be avoided by infusion into large-bore veins as well as pretreatment with intravenous lidocaine. Injecting lidocaine, 10–25 mg intravenously, before giving propofol or drawing up the lidocaine into the syringe after first filling it with propofol will ameliorate or eliminate completely the discomfort in most patients.
Infectious hazards associated with propofol have been well documented because the base, which is composed of an emulsion of soybean oil and egg phosphatides, serves as an excellent culture medium for the growth of bacteria. It is important to draw up the drug in an aseptic fashion and shortly before it is to be administered. Additionally, it is imperative that the syringe be discarded after single patient use. Repeated use of the same syringe throughout the day for multiple patients has been associated with clusters of cases of bacterial septicemia.
21.异丙酚在门诊麻醉的地位？
异丙酚可用于区域麻醉镇静，全麻诱导和维持。非水溶性，高蛋白，高脂混合物具有的药代动力学特征使它适用于门诊手术。快速再分布，肝内和肝外（肺）同时清除可以使认知功能快速恢复，术后镇静状态和宿醉感较传统的超短效戊巴比妥类很轻。它有剂量依赖性的中枢抑制效应，应用范围包括轻度镇静到睡眠到无意识。它既没有逆行性也没有顺行性遗忘的作用。可以用2–2.5 mg/kg缓慢静推诱导，静脉0.1–0.2 mg/kg/min持续输入维持。虚弱病人和老年病人适当减量。区域麻醉镇静，可以追加10-20mg(0.3 mg/kg),或开始输注。和其他静脉全麻药一样，它有明确血药浓度和治疗效应关系。异丙酚可以手术的麻醉靶浓度是3-6 mg/ml。
单独应用，异丙酚提供全过程100%的睡眠，已经有术中知晓的报道。因此经常联合挥发性麻醉药N2O或咪唑安定联合使用。它也没有肌松和镇痛作用。全静脉麻醉时，可以采用短效类阿片类药物如瑞芬太尼与异丙酚同时输注。追加负荷剂量的异丙酚可以快速加深麻醉。另一个优点是术后恶心、呕吐发生率显著低。它内在的抗呕吐效应使病人即使在PACU发生了呕吐，也可以让病人离开。在诱导和麻醉维持1小时都使用时也较硫喷妥钠诱导，异氟醚和N2O维持显著恢复的快。异丙酚麻醉后恢复质量较高，可以和术前水平媲美。术后镇痛药需要较少，这可能和恢复质量较高有关。
无镇痛作用和注射痛是异丙酚的两个缺点。对于前者，联合使用阿片类药物如瑞芬太尼和芬太尼可以提供需要的镇痛。选择较粗的静脉和静脉预给利多卡因可以消除注射时的不适。给异丙酚前静脉利多卡因10-25mg或第一次抽异丙酚的注射器用利多卡因湿润一下都可以完全减轻或消除大多数病人的不适。
已经证明异丙酚有感染的危险，因为它本身是由大豆油和卵磷脂混合的乳剂，是细菌生长的良好培养基。无菌和使用前短暂放置都是很重要的。另外，要强制在每个病人使用后扔掉注射器。同一注射器多个病人全天使用会导致群发菌血症。
22.What is total intravenous anesthesia (TIVA), and what are its advantages and disadvantages?
TIVA is a technique in which continuous or bolus doses of intravenous infusions of anesthetic drugs are administered for induction and maintenance of anesthesia (Table 77.2). The various components of a general anesthetic—hypnosis, amnesia, analgesia, as well as muscle relaxation—can be individually provided and controlled by varying the rates of infusion, thereby influencing serum concentrations. The depth of anesthesia can be controlled in a similar manner to dialing in desired concentrations on a vaporizer.
TIVA avoids the use of all gases with the exception of oxygen, compressed air, or helium. Therefore, contamination of the operating room suite that invariably occurs when using volatile agents, despite the use of scavenger systems, may be eliminated entirely. Intravenous drugs are used to provide unconsciousness, anesthesia, and muscle relaxation, if desired. Because nonflammable gases may be employed, the technique is ideal for laser surgery. For procedures on the upper airway, TIVA is perfect for use with jet Venturi ventilation. Additionally, intravenous anesthesia does not depend on normal pulmonary function for either wash-in or washout of active agent.
The further refinement of computer-assisted infusion systems will allow the anesthesiologist to achieve therapeutic blood concentrations of various anesthetic and sedative drugs. Episodes of “light” anesthesia can be treated with bolus doses or increased rate of infusion. Additional benefits of the technique are the potential for attainment of rapid awakening at the conclusion of the surgical procedure and decreased nausea and vomiting in the postoperative period in patients who receive propofol.
Since few facilities have monitors that measure the blood concentration of the intravenous anesthetics, a potential disadvantage of the technique may include the risk of patient awareness during surgery. However, presently there are several monitors that use processed electroencephalography (EEG) data to monitor the depth of sedation, and may in fact decrease the risk of awareness during a general anesthetic. Each monitor uses a proprietary algorithm to analyze EEG data to derive a linear score of 0–100. A score of 0 usually denotes complete EEG suppression while a score of 100 usually correlates with the awake unsedated state. Each monitor has its own range of numbers that correlate with general anesthesia. These monitors have proven to be very helpful intraoperatively in the decision-making tree of the anesthesiologist.
Traditionally, when a patient became hypertensive or tachycardic intraoperatively, the anesthesiologist would usually deepen the anesthetic. However, this change in vital signs can be attributed to several causes, and has been repeatedly shown to correlate very poorly with anesthetic depth. The most common of these causes are “light” anesthesia, pain, or intrinsic hypertension. If during this period of increased heart rate and blood pressure there is a concomitant rise in the score to above the general anesthesia level, the most likely cause is “light” anesthesia. Thus, the appropriate response would be to deepen the depth of anesthesia with a bolus of propofol. If, however, the score on the monitor of anesthetic depth remains within the range for general anesthesia, the response would be to give an opioid for pain. The choice of opioid would be either an ultra-short-acting opioid, such as remifentanil, for a short-lived painful stimulus (i.e., esophagoscopy) or a longer acting opioid, such as fentanyl, for a persistent painful stimulus (i.e., an incision). However, care must be taken to utilize the information gleaned from a depth of anesthesia monitor in conjunction with all clinical data, including the procedure being done, the medical condition of the patient, the patient’s need for perfusion to the vital organs, as well as hemodynamic variables.
Monitors of anesthetic depth are particularly useful in the ambulatory setting since they have been associated with decreases in times to extubation, postoperative nausea and vomiting, and time to home readiness. Whether or not it is cost-effective to utilize this monitor on all patients has been heatedly debated in the anesthesia community.
22.什么是全静脉麻醉（TIVA），优缺点是什么？
TIVA是一种通过静脉分次或持续给药进行麻醉诱导与维持的技术（表77.2）。全麻的多种指标如-催眠、遗忘、镇痛和肌松都可以通过分别给药和改变比例影响血药浓度来实现。麻醉深度也可以像波动挥发罐刻度达到预期一样进行调节。
TIVA不使用氧气，压缩空气和氦以外的气体。尽管使用了净化系统，挥发性麻醉药或许可以完全清除，但是还是常会污染手术室。如果需要静脉麻醉药可以使意识消失，产生麻醉和肌松。因为使用的都是不可燃气体，所以对于激光手术是很理想的技术。对于上呼吸道手术采用高频通气也很完美。另外，静脉麻醉药不依赖于正常肺功能或活性吸附剂洗脱来消除。
计算机辅助输注的进一步精细可以使麻醉医生获得各种麻醉和镇静药治疗范围的血药浓度。偶发的“浅”麻醉可以通过静推负荷量药物或增加输注率解决。这项技术优点还包括可以通过总结手术进程快速清醒，使用异丙酚降低术后期的恶心、呕吐等。
只有很少的仪器能够监测到血药浓度，所以这项技术有发生术中知晓的潜在风险。事实上，现在有几种做脑电图（EEG）的仪器可以用来监测镇静程度，可以降低全麻过程中术中知晓的风险。每个仪器都可以用它自带的程序分析脑电图，并进行0-100的评分。0分代表EEG完全被抑制，100分代表清醒不佳镇静状态。已经证明对于麻醉医生术中做出决定的判断是有用的。
一般当病人术中出现高血压和心动过速的时候，麻醉医生会加深麻醉。而实际上，几种原因都可以出现这些生命体征，再三提到和麻醉深度基本无关。最常见的原因是“浅”麻醉，疼痛或本身就有高血压。如果评分高于全麻水平，而血压和心率同时升高，最可能的原因就是“浅”麻醉。合适的处理就是静推异丙酚加深麻醉。如果评分在全麻范围内，处理就是给予阿片类药物镇痛。可以选择超短效的瑞芬太尼处理短暂疼痛刺激（如，食管镜），或较长效的芬太尼处理持续的疼痛刺激（如，切口）。事实上，要综合监测的麻醉深度和所有临床资料来处理，包括手术进程，病人情况，重要脏器的灌注和血流动力学的改变。
麻醉深度监护仪在门诊手术室是很有用的，因为它和减少拔管时间，术后恶心、呕吐及回家准备的时间相关。对所有病人应用是否物有所值一直是麻醉界讨论热点。
23.What is moderate sedation, when is it employed, and what advantages does it offer?
Moderate sedation, previously known as conscious sedation, is a technique that strives to achieve a decreased level of consciousness during surgery whereby patients remain capable of independently maintaining the airway with reflexes intact, as well as responding appropriately to verbal instructions. When properly executed, moderate sedation provides anxiolysis, amnesia, and allows maximum patient comfort and safety. Moderate sedation should be considered to be a valuable accompaniment and adjunct to a properly placed local anesthetic or regional anesthetic. Because interference with short-term memory occurs, the patient experiences a markedly distorted perception of time. Therefore, the anesthesiologist can increase a patient’s tolerance and acceptance of the discomforts associated with an ongoing procedure by providing encouragement and a sense of well-being and security. The goal is to allow the patient, anesthesiologist, and surgeon to communicate throughout the operative procedure.
Moderate sedation is achieved by careful titration of intravenous agents administered by either intermittent bolus injection or continuous infusion. Since moderate sedation is part of a continuum, it is possible for moderate sedation to progress to deep sedation or even general anesthesia. Propofol, midazolam, and remifentanil have ideal pharmacokinetic properties for the provision of moderate sedation. These characteristics include a rapid onset, easy titration, and a relatively short duration of action, which allow for an early recovery from their effects. It is useful to combine a benzodiazepine with an opioid. However, one must be vigilant for the insidious or sudden onset of respiratory depression including apnea. Hypoxemia or apneic episodes have been demonstrated to be more frequent when a combination of benzodiazepines and opioids is used, as compared with either drug used alone. Therefore, supplemental oxygen should be provided via mask or nasal cannula, and respiration should be carefully monitored.
Present standards of care require monitoring of heart rate, blood pressure, respirations and oxygen saturation, as well as the capability of measuring temperature and ECG. Nasal cannulae are now available with a separate tube that can be attached to the sampling probe from a capnograph, thereby allowing for end-tidal CO2 monitoring. This is particularly useful during procedures where the anesthesiologist may be physically separated from the airway.
Though a patient may appear awake and fully recovered at the end of surgery using this technique, vigilance must be maintained throughout the postoperative period because delayed respiratory depression may occur. In the PACU, hypercarbia or even respiratory arrest may occur if the patient is left unstimulated.
23.什么是适度镇静，何时给药，优点是什么？
适度镇静，先前认为是保留意识的镇静状态，它是一种术中保留病人气道反射和对口头指令适度反应能力的同时又尽力降低意识水平的技术。正确应用这项技术，可以产生抗焦虑、遗忘，使病人最大限度的舒适、安全。适度镇静可以和局麻或部位麻醉同时使用，也可作为辅助使用。因此，麻醉医生可以通过鼓励，让病人有情况不错，很安全的感觉来增加病人手术过程的耐受和对不适的适应。目标就是整个过程中让病人、麻醉医生、外科医生可以进行交流。
精确给静脉药物可以产生适度镇静，如间断静推或持续输注。既然适度镇静只是一个连续过程中的一短时间，因此有可能进一步发展为深镇静，甚至全身麻醉。异丙酚、咪唑安定、瑞芬太尼都有产生适度镇静的药理学特性。包括快速起效，易于定量，和使病人快速恢复的相对短效。苯二氮卓类与阿片类联合应用效果较好。但是，必须考虑到存在隐匿或突发呼吸抑制的风险，包括呼吸暂停。低氧或突发的呼吸暂停在苯二氮卓类与阿片类联合应用时较单独使用高发。因此，应该用面罩，鼻导管给氧，细心监测呼吸功能。
当前的监护标准包括心率、血压、呼吸和氧饱和度，尽可能监测体温和ECG。鼻导管可以单独连接到二氧化碳分析仪上采样，行呼气末二氧化碳监测。在术中当麻醉医生远离呼吸道时这非常有用。
采用这项技术后，尽管在手术结束病人看起来清醒完全恢复了，但是整个术后期应该保持警觉状态，因为可能会有延迟呼吸抑制发生。在PACU，如果病人在没有刺激状态下常有高碳酸血症甚至呼吸间停发生。
24.When tracheal intubation is required for a short procedure, can one avoid the myalgias associated with succinylcholine?
Until the development of mivacurium, a short-acting nondepolarizing agent, patients who required tracheal intubation for surgical procedures less than 20 minutes in duration could be managed only by the administration of a bolus dose of succinylcholine to facilitate intubation followed by a continuous infusion for maintenance of neuromuscular blockade. Alternatively, after administering succinylcholine for intubation high concentrations of isoflurane could be administered to provide a satisfactory degree of muscle relaxation. Isoflurane could also be used to facilitate the action of small doses of a short-acting nondepolarizing muscle relaxant. However, the use of high concentrations of a volatile anesthetic can result in delayed awakening, an undesirable consequence in the setting of ambulatory surgery.
Disadvantages of succinylcholine include postoperative myalgias and the potential triggering of malignant hyperthermia. At times, myalgias, which occur 5 times more commonly after ambulatory surgery than in the inpatient population, may far outlast the discomforts associated with the surgical procedure itself. These muscle pains may vary in intensity from mild to incapacitating in nature and often develop on the first postoperative day.
Mivacurium, like succinylcholine, is degraded by plasma cholinesterase. In the patient with atypical pseudocholinesterase, the effective duration of action is markedly prolonged. However, it may still be possible to antagonize the drug. Ordinarily, the majority of the mivacurium is rapidly hydrolyzed to inactive metabolites. The recommended intubating dose is 0.2–0.25 mg/kg in adults. When employing the 0.25 mg/kg dose, an initial dose of 0.15 mg/ kg should be followed 30 seconds later by 0.10 mg/kg. In children, a dose of 0.2–0.3 mg/kg is often used. Satisfactory intubating conditions are usually achieved in approximately 1.5–2.5 minutes. The duration of neuromuscular blockade is 15–20 minutes in adults but only 9–11 minutes in children. Unfortunately, mivacurium is not free of side-effects. The drug may cause histamine release, which may cause cutaneous flushing and even bronchospasm and hypotension in some patients. Hypotension has not been a problem when dosage guidelines are not exceeded and the drug is administered slowly. Antagonism can be easily accomplished by conventional dosages of edrophonium or neostigmine administered in conjunction with the appropriate anticholinergic agent. Twenty minutes after a single bolus dose, it may be unnecessary to antagonize the block when the train-of-four has returned to normal and fade is not present to a tetanic stimulus.
24.短小手术何时需要气管插管，能避免司可林相关的术后肌痛吗？
在短效去极化肌松药美维松的使用前，对于少于20分钟手术气管插管只有选择司可林负荷量后持续输注来维持神经肌肉阻滞。另一个选择是司可林插管后高浓度异氟醚吸入维持肌松满意度。异氟醚可用来增强小剂量短效非去极化肌松药的作用。但，高浓度挥发性麻醉药易导致延迟清醒，这恰是门诊手术不希望出现的。
司可林的缺点包括术后肌痛和有潜在诱发恶性高热的可能。有时，门诊较住院手术病人发生率高5倍，它能较手术本身引起更长远地不适。疼痛程度可以是轻度到不能忍受不等，多在术后第一天发生。
美维松，和司可林一样，依靠血浆胆碱酯酶代谢。若病人存在假性胆碱酯酶，作用时间显著延长。这时，仍有进行对抗的可能。通常，美维松大部分快速水解为没有活性的代谢产物。成人推荐插管剂量是0.2–0.25 mg/kg。插管用0.25 mg/kg后，30秒后给初始剂量0.15 mg/ kg，以后为0.10 mg/ kg。儿童常用0.2–0.3 mg/kg。大约1.5-2.5分钟达到满意的插管条件。肌松持续时间成人15-20分钟，儿童仅有9-11分钟。当然，美维松也免不了会有副作用。它可以引起组胺释放，导致有些病人皮肤潮红，甚至支气管痉挛和低血压发生。如果给药不超过推荐剂量，并且缓慢给药，低血压不应该成为问题。常规剂量的滕喜隆或新斯的明等抗组胺药联合适量的抗胆碱药可以很好的拮抗。单次用药20分钟后，当四个成串刺激（TOF）恢复正常和强直刺激消退后，没有必要再进行拮抗。
25.Can a relative overdose of benzodiazepines be safely antagonized?
Flumazenil is an intravenously administered competitive benzodiazepine receptor antagonist at specific benzodiazepine binding sites in the central nervous system. It can be judiciously titrated to obtain the desired degree of benzodiazepine reversal as evidenced by patient arousal. Previously, two drugs were available for this purpose. Physostigmine, a nonspecific centrally acting arousal agent, appears to antagonize the central nervous system depressant effects of both volatile anesthetic agents and benzodiazepines with some success. Aminophylline also appears to be a nonspecific antagonist of benzodiazepine depression but itself has side-effects.
Within 1–2 minutes of an intravenous dose, flumazenil permits awakening of a patient who may have become oversedated by benzodiazepines. If necessary, restoration to baseline levels of lucidity and alertness may be possible. Anesthesiologists may find this new drug useful in three clinical situations. First, flumazenil may be useful in the intraoperative period when a patient becomes confused, uncooperative, or combative after benzodiazepine administration. Second, it may be infused at the conclusion of surgery, when the rapid return of consciousness was the desired objective but was not attained. Flumazenil might be useful either before or after extubation following upper airway surgery when bleeding or secretions might pose a significant problem in the patient who remains excessively somnolent. Third, either intraoperatively during moderate sedation or in the PACU, reversal of excessive midazolam sedation may allow a patient to safely tolerate the central nervous system depressant effects of other drugs that were administered concurrently.
The recommended dose of flumazenil is 0.2 mg given intravenously over 15 seconds. Its onset of action is 1–2 minutes, and its peak action is 6–10 minutes. Incremental doses may be administered every minute, up to a total of 1 mg. Some recommend administration of the full 1 mg dose as a single bolus. Because flumazenil is a specific reversal agent with selectivity for benzodiazepine-induced sedation, it does not interfere with the analgesic state afforded by previously administered opioids. Its duration of action is highly variable, ranging from 20 minutes to 3 hours. Resedation may occur, and close patient surveillance is important. Resedation might occur in someone who received excessive doses of benzodiazepines, especially those agents with longer half-lives such as diazepam or lorazepam. If recognized, resedation can be safely managed by repeat administration of flumazenil at 20 minute intervals as required. Although excessive sedation and tranquility may be antagonized, flumazenil may not sufficiently reverse all the psychomotor and cognitive impairments induced by benzodiazepines. Thus, a false sense of security may be engendered. Furthermore, flumazenil may not entirely reverse respiratory depression caused by benzodiazepines. Mild side-effects reported in association with flumazenil administration include pain at the site of injection, dizziness, headache, precipitation of nausea and vomiting, acute anxiety, and disorientation. Seizures have also been precipitated in patients who have chronically used excessive amounts of benzodiazepines for anxiety or seizure control.
Midazolam has varying effects at different dosages. With small doses, it is anxiolytic. Increasing the dose administered increases the amount of sedation encountered. With still additional midazolam, the hypnotic effects of the agent become manifest. Careful titration of flumazenil may allow partial antagonism of excessive benzodiazepine effect.
When contemplating the use of any reversal agent in the setting of ambulatory surgery, it is important to remember that the duration of action of flumazenil, as well as naloxone, is short-lived. Therefore, additional patient observation before discharge from the PACU is required whenever these agents have been administered.
25.相对大剂量的地西泮能被安全拮抗吗？
氟马西尼是一种静脉应用的，作用于苯二氮卓类受体结合位点的竞争性特异拮抗剂。在病人唤醒中证明，精细给药可达到苯二氮卓类拮抗预期水平。以前，有2种药被用来拮抗。毒扁豆碱，一种非特异性中枢唤醒药，有拮抗挥发性麻醉药和苯二氮卓类药中枢抑制效应成功的例子。氨茶碱也显示出有拮抗苯二氮卓类抑制的效应，但它本身也有自己的副作用。
氟马西尼静脉给药后，1-2分钟可以使因为使用苯二氮卓类药过度镇静的病人清醒。如果有必要，恢复到正常人清醒度和灵敏度也是有可能的。麻醉医生会在下面的三种情况下发现这种新药是有用的。第一，术中病人用过苯二氮卓类药后出现意识混乱，不合作或好斗时可以使用。第二，当手术快要结束时，想让意识快速回到预期目标，但是没能达到时；一些上呼吸道手术后嗜睡的病人，如果有出血或分泌物会造成严重后果，拔管前或拔管后都适于使用。第三，术中或PACU中适度镇静。过量咪唑安定镇静作用的逆转，可以使病人更安全的耐受由其他药物产生的中枢抑制效应。
氟马西尼静脉推荐剂量0.2mg，大于15秒给完。起效时间1-2min，作用峰时间6-10min，可以每分钟增加一次剂量，直到总量达到1mg。也有推荐单次剂量1mg。因为氟马西尼是一种高选择性特异拮抗剂，它对阿片类产生的镇痛状态没有作用。它的作用时间变化较大，从20min到3h不等。再次回到镇静状态是有可能发生的，因此近距离陪伴病人是很重要的。对一些接受大剂量苯二氮卓类药物的病人可能会重新回到镇静状态，尤其使用的是一些半衰期较长的药物如地西泮，劳拉西泮等。如果原因明确，可以间断20min重复给氟马西尼安全的对镇静状态进行管理。尽管过度镇静或安静状态可以被拮抗，但不能完全逆转所有苯二氮卓类产生的精神活动和负性损害。因此，不应有一种错误的安全观。并且氟马西尼也不能完全逆转苯二氮卓类呼吸抑制作用。氟马西尼轻微的副作用包括注射痛、眩晕、头痛、恶心呕吐，急性焦虑，和定向力障碍。已经有慢性使用大剂量苯二氮卓类药抗焦虑，抗惊厥病人产生惊厥的报道。
当认真思考门诊手术使用的每一个拮抗药时，都要记得和纳络酮一样，氟马西尼也是短效的。因此，病人离开PACU之前要进行观察，不论这种药是否还有作用。
26.Do the newer volatile agents offer advantages over older agents such as enflurane and isoflurane?
Two volatile anesthetic agents, desflurane and sevoflurane, both ethers, have been extensively tested. Desflurane is a clear nonflammable liquid that is extremely insoluble and requires a specially designed, heated vaporizer for administration. Unfortunately, the gas has a strong odor and is a powerful airway irritant. It can produce coughing, breath-holding, and laryngospasm; therefore its use as an inhalation induction agent is precluded. Its major advantage is low blood and tissue solubility, which allows for a fast emergence when compared with currently available volatile agents. Low solubility properties also allow rapid titration of anesthetic depth.
Although desflurane and isoflurane have similar muscle relaxing properties, higher levels of desflurane can be administered without concern about a delayed emergence. Studies to date have revealed that the times to ambulation and discharge with desflurane are similar to those seen with propofol, although patients anesthetized with desflurane appear to be less sedated in the early postoperative period. However, nausea and vomiting were less frequent with propofol.
Sevoflurane is nonpungent and odorless, and coughing and breath-holding are absent on rapid inhalation induction. Its solubility in blood approaches that of nitrous oxide. Fires have been reported when sevoflurane is used in the presence of desiccated soda lime. Both sevoflurane and desflurane can provide sufficient muscle relaxation to allow tracheal intubation. Both can trigger malignant hyperthermia.
26.新型挥发性麻醉药相对于安氟醚和异氟醚优越吗？
两个挥发性麻醉药，地氟醚，七氟醚，都是醚类，并进行过广泛的研究。地氟醚是一种非常难溶的不可燃液体，使用时需要特殊设计可以加热的挥发罐才行。不幸的是，它还有强烈的气味和很强的气道刺激性，它会使病人咳嗽、屏气和产生喉痉挛；因此被排除用于吸入诱导。它主要的优点就是血液和组织中溶解度低，和现在使用的挥发性麻醉药相比起效较快。溶解度低的特性也使其可以快速加深麻醉。
尽管地氟醚和异氟醚有相似的肌松效果，但高浓度的地氟醚不出现延迟清醒。研究已经有的资料发现，使用地氟醚后病人下地行走和离开的时间和用异丙酚相似，尽管术后早期镇静不如使用异丙酚。恶心、呕吐发生率使用异丙酚也较低。
七氟醚无臭，无味，快速吸入诱导无咳嗽、屏气发生。溶解度接近N2O。有与粉状钠石灰一起使用燃烧的报道。七氟醚和地氟醚都可以提供插管所需的足够的肌松，都可以引起恶性高热的发生。
27.What are the etiologies of nausea and vomiting, and what measures can be taken to decrease their incidence and severity?
Unfortunately, postoperative nausea and vomiting remain a significant problem in patients who receive either general anesthesia or intravenous sedation. They are among the most commonly reported complications associated with ambulatory surgery, and hospitalization following an ambulatory procedure is often attributable to them. Persistent and severe retching or vomiting can disrupt surgical repairs and cause increased bleeding; left untreated, they may lead to dehydration and electrolyte imbalance. From 10% to 40% of patients who have not received anti-emetic prophylaxis may be expected to experience some degree of nausea or frank vomiting. The incidence of nausea and vomiting depends on the type of surgical procedure performed, as well as the anesthetic administered. It has been demonstrated that patients undergoing laparoscopy have a 35% incidence of nausea and vomiting. This may be due to manipulation of abdominal viscera, retained intraperitoneal carbon dioxide, and the use of electrocautery. Symptoms occur regardless of whether a general anesthetic or epidural technique is employed. Arthroscopic surgical procedures are associated with a much lower incidence of symptoms than laparoscopic surgeries or ovum retrievals.
The cause of postoperative nausea and vomiting is multifactorial (Table 77.3). Obesity, sudden movement or changes in patient position, a history of motion sickness, postoperative hypotension, female gender, days 4 and 5 of the menstrual cycle, pain, opioid administration, the anesthetic technique used, and site of surgery may all contribute to the establishment and persistence of these symptoms. They are often disquieting and sometimes incapacitating. Physical measures as well as pharmacologic agents have been employed in an attempt to reduce the incidence of these distressing sequelae. Examples include the attempted removal of stomach contents by intraoperative gastric suctioning; avoidance of excessive positive pressure during mask ventilation, which may force gas into the stomach; and diminished use of opioid-based general anesthesia. These have proven to have variable effects in the reduction of nausea and vomiting, probably because the problem is strongly multifactorial in nature.
Nitrous oxide has been both implicated and exonerated in multiple studies. It is unlikely that this gas plays a major role in influencing the presence or absence of nausea in the postoperative period. However, the selection of induction agent does influence the incidence of postoperative symptomatology. Etomidate and ketamine are associated with a much higher incidence of these symptoms when compared with thiopental. General anesthesia induced and maintained with propofol is associated with the least number of episodes of nausea and emesis.
To help prevent symptoms, moving patients slowly from the operating room table to the stretcher, avoiding sudden turns during transport to the PACU, and allowing patients to wake up slowly have been applied with some measure of success. Warm blankets and repeated verbal reassurance may reduce overall anxiety by increasing feelings of well-being and a sense of security. A vigorous stir-up, sit-them-up regimen with early oral intake is likely to precipitate nausea and vomiting. The end result of significant symptomatology is an increased length of stay in the PACU. For the patient with unremitting symptoms, overnight admission for observation and further treatment with anti-emetics and intravenous fluids to prevent dehydration may be required.
Adequate hydration must be ensured during the operative period as well as maintained in the PACU. To avoid precipitating episodes of nausea or vomiting postoperatively, it is recommended to hydrate vigorously intraoperatively with at least 15–20 mL/kg of crystalloid solutions and to avoid pushing oral fluids and food. Intravenous fluid repletion allows oral fluids to be offered sparingly. Solids should be withheld until the patient expresses hunger. In addition, postponing early ambulation may help to reduce symptoms.
Prophylactic administration of dexamethasone (4–10 mg IV) at the beginning of the procedure, and metoclopramide (10 mg IV) have been advocated. Droperidol, a potent anti-emetic, has fallen into disfavor because of its association with QT prolongation and torsades de pointes. This led the FDA to issue a black-box warning regarding its use. The FDA’s recommendations have been challenged because of droperidol’s long history of efficacy and rare occurrence of adverse events. If one decides to administer droperidol, a baseline ECG should be performed, and the QT interval should be measured. Furthermore, the ECG should be monitored during its administration (Table 77.4).
Unfortunately, clinically significant side-effects have been reported with these agents. These include prolonged sedation and delayed awakening, an increase in anxiety as well as restlessness, and extrapyramidal symptoms. Acute dystonic reactions including torticollis, tics, or an oculogyric crisis can be treated with diphenhydramine, 25–50 mg, or with benztropine, 1–2 mg, intravenously or intramuscularly.
Transdermal scopolamine, proven earlier to be efficacious in the prevention of motion sickness, has been studied for the prevention of postoperative nausea and vomiting. Although effective in reducing symptoms when applied 12 hours before surgery, significant side-effects including dry mouth as well as sedation, dysphoria, and urinary retention may occur. It is often reserved for preoperative use in patients who have a strong history of motion sickness. In the pediatric age group, the incidence of visual disturbances and hallucinations after application of the patch is increased. Some clinicians have placed the patch before discharge in patients whose nausea has not completely resolved. However, the patch should be avoided in the geriatric population, pregnant or lactating patients, and in patients with glaucoma.
Ephedrine has been used in the treatment of nausea and vomiting in the PACU. Hypotension or documented postural hypotension in the postoperative period is often due to an intravascular volume deficit and should be ruled out. Treatment consists of crystalloid infusion to correct hemodynamic instability. Ephedrine has been demonstrated to be useful in patients whose symptoms are causally related to assuming the upright position. Ephedrine, 0.5 mg/kg given intramuscularly, has been used in laparoscopy patients with some success. Patients who received ephedrine also had lower sedation scores, and no differences in mean arterial blood pressure were noted. It may be indicated in otherwise healthy patients who have a history of motion sickness or in those patients who experience dizziness, nausea, or vomiting when attempting to ambulate in the postoperative period.
A popular drug in the anesthesiologist’s armamentarium against nausea and vomiting, ondansetron, is a serotonin receptor antagonist with possible central and peripheral sites of action. It does not appear to affect awakening from general anesthesia and has no extrapyramidal effects or sedative qualities. Ondansetron appears to offer improved control over both nausea and vomiting. The effective dose is 2–4 mg intravenously and has a duration of action of up to 24 hours. An oral formulation is also available. It has been demonstrated that a combination of agents, perhaps in conjunction with propofol, will prove to be most efficacious in the prophylaxis of nausea and vomiting.
Many surgical centers have abandoned the routine administration of prophylactic anti-emetics to every patient. However, anti-emetic regimens should be administered for specific surgical procedures, such as strabismus repair or laparoscopic surgery, that are associated with an extraordinarily high incidence of postoperative nausea and vomiting.
Sometimes simply relieving postoperative pain may alleviate nausea. The use of acupuncture has been reported in some studies to be effective, but its use is not widespread. A propofol-based anesthetic is associated with fewer emetic symptoms, earlier ability to tolerate oral alimentation, and shorter stays in the PACU when compared with induction with a thiobarbiturate and maintenance with isoflurane. Unfortunately, despite careful anesthetic management including propofol and even prophylactic medication, symptoms of nausea and vomiting in the postoperative period still remain a problem.
27.恶心、呕吐的病因学是什么？哪些措施可以减少发生率和降低发作程度？
恶心、呕吐是接受全麻或镇静病人术后的一个大问题，他们是门诊手术病人最常报告的并发症，也是门诊手术病人术后住院的主要原因。持续严重的干呕或呕吐可以撕裂伤口修复，导致出血；如果不加处理，会导致脱水和电解质失衡。预计会发生某种程度恶心、呕吐的病人有10-40%的病人没有被给予抗呕吐药物。已经证明腹腔镜手术病人有35%的恶心、呕吐率，原因有内脏操作，腹腔内CO2残留，和电刀的使用。相比之下，关节镜手术要较腹腔镜和睾丸复位手术低得多。
术后恶心、呕吐的原因是多样的（表77.3）。肥胖，病人位置的突然运动或改变，女性，月经期的4，5天，疼痛，阿片类的应用，所使用的麻醉技术，手术部位都和这些症状的发生和维持有关。病人对恶心、呕吐感到不安甚至不能忍受。物理治疗和药物治疗都试图减少发生率。如术中胃管吸引减少胃内容物；面罩通气时过高压力的避免，这会迫使气体进入胃内；以阿片类为主的全麻的减少等。都证明能不同程度使恶心、呕吐的发生减少，或许这个问题本身就有很多的影响因素。
很多研究表明和N2O关系不大。这种气体对术后期出现或不出现恶心不起主要的作用。实际上，诱导药物的选择影响术后这些症状的发生率。依托咪酯和氯胺酮较硫喷妥钠发生率高，全麻时用异丙酚诱导和维持术后恶心、呕吐发生率最低。
为了减少这些症状，在把病人转运到担架时要慢，避免在转运到PACU时突然转弯，允许病人缓慢苏醒都是成功的先例。使用变温毯和重复口头安全保证可以通过使病人感觉情况不错和有安全感来减少过度焦虑。鼓励早期坐起经口进食也很有效。对症状较重的最后办法就是延长在PACU的时间。对于有连续症状的病人，要进行过夜观察和进一步抗呕吐和静脉输液防脱水治疗是需要的。
和在PACU一样，术中不许保证足够的液体。为了避免术后恶心或呕吐的发生，推荐术中快速补至少15–20 mL/kg的晶体液补足禁食带来的丢失。允许口服液体补充静脉体液量。禁止固体食物，除非病人非常饥饿。推迟仍病人行走的时间也有助于减少症状。
支持术前静脉给4-10mg地塞米松和10mg胃复安。达哌啶醇是一种有效的抗呕吐药物，因为QT间期延长及尖端扭转型室性心动过速有关已经不被赞成使用。美国FDA也发出了对它使用的警告。但是因为达哌啶醇长期有效的历史和有害效应极低的发生率，美国FDA的推荐也遭到了挑战。但当决定给药时，要监测ECG基线和QT间期，另外使用过程中要监测ECG。
不幸的是，临床这些药物的副作用已经有报道。包括长时间镇静状态，延迟苏醒，坐立不安的焦虑，和锥体外系症状的发生。急性张力增加的反应包括斜颈、局部抽搐，或动眼神经危象可以用苯海拉明25-50mg或苯甲托品1-2mg静脉或肌注治疗。
以前治疗运动性眩晕的东莨菪碱经皮贴剂已经被研究用来预防术后恶心、呕吐的发生。尽管术前12h应用对减轻症状有效，但它会出现口干，烦躁，尿潴留等和镇静药同样显著的副作用。它常适用于有运动性眩晕病史的病人。这种贴剂应用后儿童视觉障碍和幻觉发生率增加。一些临床医生常对尚未完全恢复的病人离开时给予。避免对老年病人，孕妇或哺乳期妇女，及青光眼病人使用。
麻黄碱已经被用来治疗PACU发生的恶心呕吐。低血压或诊断明确的直立性低血压常是由于容量不足引起的，不包括在内。可以输注晶体液来纠正血流动力学的不稳。麻黄碱对平卧位有症状的病人有效。腹腔镜术后病人0.5 mg/kg肌注，一些病人很有效。使用麻黄碱的病人镇静评分也较低，平均动脉压变化不大。对有运动性眩晕病史或术后试图行走的发生头晕、恶心、呕吐的病人是应用指征。
麻醉医生手中流行的另一个抗恶心呕吐药是昂丹司琼，一种可能存在的中枢和外周5-羟色胺受体拮抗剂。它不影响全麻病人的清醒，椎体外系症状或镇静的质量。它显示出很好的控制恶心和呕吐。有效剂量2-4mg可以持续作用24h。口服剂型也可应用。有报道联合其他药物，或许是异丙酚可以预防绝大部分恶心呕吐的发生。
现在，很多手术中心已经不常规对每个病人使用抗呕吐药物。但对于一些特殊病人如斜视修复或腹腔镜手术病人应该给予，因为这些病人术后恶心、呕吐发生率特别高。
有时只是简单的减轻术后疼痛就可以减轻恶心。已经有一些研究报道针灸也是有效的，但是还没有得到广泛的使用。和硫喷妥类诱导，异氟醚维持比较，异丙酚为主的麻醉呕吐症状较少，可以早期难受经口进食，和在PACU时间较短。不幸的是，尽管应用了包括异丙酚和其他预防用药，术后恶心、呕吐症状仍然是一个存在的问题。
28.How is pain best controlled in the ambulatory patient in the PACU?
Management of postoperative pain in the PACU as well as after discharge is of major concern to the anesthesiologist. Adequate pain relief must be achieved before a patient may be discharged and patient comfort in the postoperative period is important. The prevention of postoperative pain appears much easier to accomplish than the treatment of pain that has been allowed to reach significant intensity. Unfortunately, the occasional inability to manage postoperative pain remains a cause of unexpected overnight hospitalization.
In procedures for which patients can be anticipated to experience significant postoperative discomfort, the addition of an opioid as part of the anesthetic is helpful. A propofol anesthetic will not provide postoperative analgesia. The intraoperative administration of long-acting local anesthetics such as bupivacaine, 0.25–0.5%, at the surgical site may provide hours of postoperative pain relief. This technique has proven to be most efficacious following inguinal and umbilical hernia repairs and minor breast surgery. The efficacy of intra-articular local anesthetics and opioids following arthroscopy of the knee joint has been shown to be of value. Other techniques such as performance of a penile block or the topical application of lidocaine jelly on the penis following circumcision have proven effective in reducing discomfort. The use of ilioinguinal and iliohypogastric nerve blocks is efficacious in adults and children following herniorrhaphy. Repeating maxillary or mandibular nerve blocks at the conclusion of oral surgery is efficacious.
In the PACU, careful titration of small intravenous doses of opioids can safely provide satisfactory analgesia. The blood levels of opioids that are required to provide analgesia are less than those that usually result in significant respiratory depression or marked oversedation. Fentanyl is the narcotic of choice in the postoperative period for treating pain. Its duration of action is modest, and intravenous doses of 25–50 mg may be repeated every 5 minutes until satisfactory pain relief has been achieved. Medicating patients with oral opioid preparations before discharge will provide a patient with a more comfortable trip home because the intravenous drugs administered in the PACU have relatively short durations of action.
The home use of patient-controlled analgesia systems permits the discharge of patients who are expected to experience pain that may not be sufficiently controlled with oral agents. Experiments with patient-controlled analgesia in the home have found this modality of pain relief to be both safe and effective. Oxycodone and codeine are suitable for amelioration of mild-to-moderate pain but are not strong enough to prevent hospitalization in a patient who experiences severe pain.
Ketorolac, a nonsteroidal anti-inflammatory agent, has been administered orally, intramuscularly, and intravenously in an attempt to prevent and relieve pain and reduce opioid requirements. The drug itself is free of opioid-related side-effects including sedation and vomiting. Some are hesitant to employ this class of drugs because of their potential for causing bleeding. Further, when administered orally, gastric irritation may be encountered. COX-2 inhibitors minimize the potential for postoperative bleeding and the risk of gastrointestinal complications and thus are becoming popular as a non-opioid adjuvant for treating postoperative pain.
29.What discharge criteria must be met before a patient may leave the ambulatory surgery center?
Most institutions divide postanesthesia care into two phases. The first phase begins when the patient first enters the recovery area. The second phase, or step-down phase, begins after stability of vital signs has been achieved and the major effects of anesthesia have dissipated. At this point, the patient can be comfortably transferred into a recliner chair, either in the same area or in another unit (Table 77.5).
Patients who have received a spinal or epidural anesthetic can only be discharged when full motor, sensory, and sympathetic function has returned. An inpatient who will remain at bed rest might be discharged from the PACU to the nursing unit while minimal residual neural blockade persists; in the case of the ambulatory patient, however, it is essential that the block has completely dissipated.
Following administration of an epidural or spinal anesthetic, the patient should demonstrate the ability to void. This provides evidence that residual sympathetic blockade has dissipated. Of course, before attempting to ambulate a patient, it is essential to ensure that all motor block has resolved.
Patients who have received an ankle block, brachial plexus block, or peripheral nerve block may be discharged despite the persistence of residual anesthesia or paresthesias. The arm or foot should be protected from harm with either a sling in the case of the arm or a bulky dressing in the case of the foot. The patient needs to be reminded that in time the block will dissipate and discomfort will appear. For this reason, instructions should be given to take the prescribed oral analgesic medication at the first sign of discomfort, because pain is most readily treated before it becomes excruciating.
Patients who have received general anesthesia may awaken either in the operating room or shortly after transfer to the PACU. Although the patient may appear to be lucid and oriented, numerous criteria must be satisfied before a patient may be considered to be ready for discharge from the facility. A restoration of vital signs within 15–20% of the preoperative baseline is ordinarily required. Patients should demonstrate an intact gag reflex and the ability to cough effectively and swallow liquids without difficulty. It is not necessary for patients to eat before discharge. Forcing patients to ingest unwanted food in the absence of hunger may simply serve to increase the incidence of postoperative nausea and vomiting. Ordinarily, the patient is asked to demonstrate the ability to tolerate a small amount of liquid. If a patient experiences mild nausea and has not been able to ingest more than a few sips without precipitating vomiting or increased nausea, it is foolish to persist. Discharge can still be considered, but written instructions must be provided regarding steps to be taken (contact facility or surgeon) if there is continued inability to tolerate fluids. It is important to ensure that a normal state of hydration has been achieved before discharge. This is especially important following surgery in the oral cavity, where postoperative pain may preclude early oral intake.
Unless the patient was previously unable to walk or the procedure performed precludes ambulation, patients should be able to walk with assistance and without experiencing dizziness. If crutches are required, it should not be assumed that the patient received preoperative instruction. Additional instruction should be offered. Hemostasis should be present at the surgical site, and control of pain should be satisfactory. The preoperative level of orientation should be achieved, although a mild degree of residual sedation is acceptable.
It is not essential for a patient to demonstrate the ability to urinate unless genitourinary, gynecologic, or other surgery has been performed in the inguinal or perineal region. The patient and the escort should be instructed of the need to contact either the ambulatory facility or the surgeon if the patient has not voided within 6 hours following discharge from the recovery area.
Postanesthesia discharge scoring systems have been proposed and developed for the purpose of assessing when home readiness is achieved in the postoperative period. Criteria such as mental status, pain intensity, ability to ambulate, and stability of vital signs are given numeric values. A total score above a particular number may indicate a high likelihood of readiness for discharge. To be practical, a scoring system must be readily understood, simple to employ, and objective. Sophisticated pen-and-paper and neuropsychological tests to assess recovery from anesthesia are reserved solely for research purposes. Actually, after stability in vital signs is achieved, the ability of a patient to walk and urinate may be the best measure of a patient’s gross recovery from an anesthetic and signal readiness for discharge. These activities indicate return of motor strength, central nervous system functioning, and restoration of sympathetic tone.
Each patient and escort should receive a set of detailed, written discharge instructions regarding activity, medications, care of dressings, and bathing restrictions. Instructions must be reviewed verbally with the patient and escort, and they must be signed by the patient or escort, if the patient is incapable. Both must be aware of the need to contact the facility in the event of untoward reactions or any difficulties that may arise such as bleeding, headache, severe pain, or unrelenting nausea or vomiting. The majority of postoperative complications occur after the patient has been discharged. Therefore, it is important to ensure comprehension of all information by the patient or designated escort (Table 77.6).
Most states have a mandatory requirement that patients who have received other than a local anesthetic be discharged in the company of a responsible adult. Current definitions of “responsible adult” vary and may be broadened to include emancipated minors or responsible older children. Theoretically, the companion should be willing and able to remain with the patient for at least the first 24 hours after surgery. This is especially important when dealing with the geriatric or debilitated patient. Problems may arise when an octogenarian patient is discharged in the company of an octogenarian spouse. Ideally, two adults should accompany pediatric patients from recovery room to home. After discharge, a child may suddenly experience nausea or vomiting, pain, fright, or disorientation. A parent who is driving a car cannot possibly attend to both responsibilities simultaneously.
A clear distinction is made between “home readiness” and “street fitness.” Home readiness signals that the time has arrived to discharge the patient from the recovery area. On the other hand, “street fitness” is attained after approximately 24 hours have elapsed, when most of the more subtle and persistent central nervous system effects of general anesthesia have dissipated. Patients must be advised not to resume normal activities immediately upon returning home.
Formal discharge criteria must be in place, and final evaluations should be conducted immediately before a patient’s discharge from the unit. All perturbations from normal, including vital signs and unusual symptoms, must be addressed.
Every attempt must be made to avoid premature discharge of the patient from the PACU. The consequences of such faulty judgments may include the necessity for emergency care elsewhere and possible readmission to another health care facility. When any element of doubt exists as to the stability or suitability of a patient for discharge, the better part of valor is to arrange for hospital admission for overnight observation.
30.What are the causes of unexpected hospitalization following ambulatory surgery?
Although a patient may be scheduled to return home after surgery, admission may be required for a host of reasons. Approximately one quarter of the unexpected admissions following surgery are anesthesia-related. The remainder result from either medical or surgical complicating factors (Table 77.7)
Most ambulatory surgical facilities experience an unexpected hospital admission rate that ranges from less than 1% to approximately 4%. Unexpected hospitalization is greater with general anesthesia compared with local or regional anesthesia. As might be anticipated, the addition of intravenous sedation to a local anesthetic increases the complication rate. Nausea and vomiting, dizziness, bronchospasm, and delayed emergence from anesthesia are common causes of anesthesia-related hospital admission.
31.When may patients operate a motor vehicle after receiving a general anesthetic?
Current recommendations are to advise patients to refrain from operating heavy machinery including driving a car for approximately 24–48 hours after the administration of either a general anesthetic or intravenous sedation. While a patient may appear to himself or herself and to others to be completely recovered, subtle psychomotor disturbances and cognitive deficiencies may persist in the postoperative period. Important decision-making, as well as activities requiring fine motor coordination, should be postponed until after the first postoperative day. Despite admonitions to the contrary, postoperative patient surveys have revealed that some patients drive their automobiles within 24 hours after surgery, and some may even drive home from the facility.
As a result of central nervous system derangements or the surgery itself, patients may experience minor slips or even major falls after discharge. Some of these events may be related to confusion or subtle alterations in mental state. Others may be due to dizziness or pain. It is hoped that anesthetic agents of the future will be free of the prolonged and potentially hazardous central nervous system dysfunction seen with currently available drugs.
32.What is the role of aftercare centers for the ambulatory surgery patient?
Following some surgical procedures, patients may experience significant postoperative pain that cannot be readily controlled with oral opioids. Additionally, although they may require some skilled nursing observation or specialized care, these may be accomplished outside the setting of an acute care hospital both at lower cost and with greater comfort for the patient and family. With this in mind, the concept of a recovery care facility was born, thus creating a new category of inpatient postsurgical care. This healthcare model integrates ambulatory surgery with overnight or extended care outside of a hospital. Examples of procedures included in the present trial include hysterectomy, cholecystectomy via laparotomy, shoulder repairs, and mastectomies. If this type of facility is unavailable, appropriate use of home care services including newer modalities of pain control may still allow a patient to avoid inpatient postoperative care.
33.Are quality assurance and continuous quality improvement possible for ambulatory surgery?
To ensure quality as well as patient satisfaction, follow-up telephone calls by an anesthesiologist should be made to all patients on the first postoperative day. Some facilities make two additional calls, one on the evening of surgery and another 1 week following surgery. Postage-paid postcards may be sent to patients requesting information on the overall experience as well as specific areas of care. Space may be allocated for the patient to note side-effects or adverse occurrences. Depending on surgeons to provide accurate feedback regarding complications is unreliable. Therefore, a mechanism for follow-up must be in place to uncover and identify patterns that may require remedial action.
28. 怎么使门诊手术病人在麻醉后恢复室（PACU）得到最好的镇痛？
PACU病人术后疼痛管理是继出院之后对麻醉医生最重要的事情。离院前必须充分减轻疼痛和病人术后期的舒适是重要的。预防术后疼痛发生较治疗疼痛达到一定的程度要容易的多。不幸的是，偶尔发生难以处理的疼痛，会导致我们不期望发生的病人不得不住院过夜留置观察。对于预测可能发生术后不适病人麻醉时，加入阿片类作为麻醉的一部分是有用的。异丙酚麻醉不能提供术后镇痛。术中手术部位给予0.25-0.5%的长效局麻药可以产生术后几个小时的疼痛减轻。在腹股沟疝和脐疝修补术，小范围乳腺手术效果都非常明显。关节镜检查后，膝关节腔内给局麻药和阿片类药物也是很有效的。其他如对包皮环切病人阴茎神经阻滞，或表面涂抹利多卡因膏剂都有助于减轻不适。髂腹股沟和髂腹下神经阻滞在成人和小儿疝修补病人都是有效的。多次上下颌神经阻滞对口腔手术病人也是有效的。
在PACU病人精确静脉给阿片类药物可以安全的达到满意的镇痛。产生镇痛的血药水平要低于引起显著呼吸抑制或过度镇静的水平。芬太尼是疼痛治疗可以选择的麻醉药。它作用时间中等，静脉25-50mg，每分钟可重复给药直道达到我们期望的减轻程度。给准备离院的病人口服阿片类镇痛药，可以使病人回家途中更舒适，因为在PACU静脉给药作用时间较短。
对认为口服镇痛药不足以有效镇痛的病人来说，家庭用自控镇痛（PCA）装置的使用也可以让病人离开医院。对病人家庭自控镇痛的研究表明它是安全、有效的。羟考酮和可待因适合改善轻中度疼痛，但对因疼痛住院的病人是不够的。
痛力克是一种非甾体类抗炎药，曾被口服，肌注和静脉给药试图预防和减轻疼痛，减少对阿片类药物的需求。它本身没有阿片类相关的恶心、呕吐等副作用。但是医生对使用这类药物很犹豫，因为它有潜在出血的危险。另外，口服时对胃有刺激。COX-2抑制剂可潜在的减少出血，和胃肠并发症的风险，因此常作为非阿片类药物治疗术后疼痛。
29. 病人离开门诊手术中心必需达到的标准是什么？
大部分机构把麻醉后监护分为两期。一期从病人进入复苏区开始。二期从病人生命体征已经稳定，主要麻醉效应已经消失开始。这时，病人可以舒适的坐进躺椅，仍在这个房间或到另一个房间（表 77.5）。
椎管内麻醉的病人只有运动，感觉和交感神经功能功能完全恢复才能离开。在PACU卧床休息的住院病人，当仅剩骶部神经阻滞时可以回到护理病房。门诊手术病人最主要的是阻滞作用完全消失。
椎管内麻醉病人应证明有排泄能力，这是骶部交感神经消失的证据。当然，准备行走的病人，运动神经完全恢复是必须的。
接受踝部阻滞，臂丛和外周神经阻滞的病人，即使麻醉作用或感觉异常持续存在也可以离开。手臂和脚或使用吊带或用较厚的包扎，要进行保护以免受伤。病人需要提醒当阻滞作用消失时会有不适。因此要给予病人指导和开出口服镇痛药在开始出现不适时使用，因为疼痛在变严重之前最好治疗。
全麻病人可以在手术室或转运到PACU不久清醒。尽管病人看起来是清醒，有正确定向力的，但让病人离开之前还有很多标准要到达满意。生命体征在术前基线范围的15-20%是基本要求的。病人要有完整的gag 反射，有效地咳嗽，无困难进食液体。没有必要让病人在离开之前进食。强迫病人感到饥饿时进食不想吃的食物只会增加术后恶心呕吐的发生。如果病人只有轻度恶心，还没有达到进食几小口不引起呕吐和恶心增加的程度，坚持让病人进食是愚蠢的做法。如果一直不能进食液体，也可以考虑让病人离开，但必须提供书面的分步骤指导（如何联系机构和外科医生）。确保离院前体液足够是重要的。尤其是口腔手术病人，因为术后疼痛导致不能早期经口进食。
除非病人术前就不能行走或手术原因，病人应该在其他设备辅助下能够行走，并且不头晕。如果需要拐杖，不要认为病人术前已接受过指导，应该给予另外的指导。手术伤口应该已经止血，疼痛控制的满意。应该回到术前的定向力水平，即使有一点轻度的镇静残余也是可以接受的。
除非是在腹股沟或会阴区进行的泌尿生殖手术，妇科或其他相关的手术，没有必要让病人证明有排尿能力。病人和护送人员要被告知，如果离开恢复区后6h仍未排泄，要通知医院或外科医生。
已经开发了麻醉后允许离开评分系统，目的是评估术后何时达到准备离开的标准。如精神状态，疼痛程度，行走能力，数字评分的生命体征的稳定性等，总评分高于某个特定值说明进行离院准备的可能性高。从实用方面讲，评分系统因该易于理解，应用简单，并且客观。精确的书面神经生理学测试已经单独用来进行麻醉恢复程度的研究评估。事实上，生命体征恢复，能够独立行走和排尿或许是对麻醉后恢复程度及可以作离院准备粗略评估的最好指标。这些活动是运动强度，中枢神经系统，交感系统恢复的表现。
每个病人和护送人员应该给予一套详细的包括活动、用药、穿衣，限制沐浴的详细指导。病人和护送人员必须口述这些指导，并签字，病人不能时，护送人员代签。两个人都必须意识到当不良反应或任何其他困难如出血，头疼，严重疼痛，严重恶心，呕吐发生时，有联系医院的需要。术后并发症大多在病人离开后发生。因此，有必要确保病人或代为签字的护送能够人员充分理解上面所有的信息（表77.6）。
大部分机构强制规定，对接受过大于一种局麻药的病人要有负责人的成人陪伴才能离开。所谓“负责人成年人”定义现在已经放宽，包括空闲的未成年人或较大的儿童。理论上讲，陪伴人员应该健康并且能在术后第一个24小时和病人呆在一起。这对老年和虚弱病人尤其重要。如果一个八旬老人被他八旬的配偶陪伴下 被允许离开，就有出事的可能。儿童出院后可能突然出现恶心呕吐，疼痛，恐惧或定向力障碍，一个正在驾车的父母可能不能同时处理好孩子。
“适合在家”与“可以上街”有明显的区别。适于在家是达到可以从恢复区离开的标准。而“可以上街”是在24h后，当大部分细微的和持续存在的全麻对中枢神经系统的影响已纪完全消失后。必须建议病人在回家后不立即进行正常活动。
病人离开前必须达到标准，并在离开前刻作最后的评估。必须排除对对正常所有状态如生命体征和异常症状的所有干扰。
必须尽最大努力避免让病人过早离开PACU。错误判断的结果就是在它处的急救和在其他医疗机构的再入院。当对病人情况的稳定性或是否离开有疑问时，最好的办法就是过夜留置观察。
30. 门诊手术后意外住院的病人怎么处理？
尽管病人术后被允许回家，但还会因为很多原因入院。其中，与术后麻醉相关的约有1/4。其他的是医疗和手术因素（表 77.7）。
大多门诊手术机构意外再入院率在低于1%到大约4%不等。全麻较局麻或部位麻醉发生率高。可以想象，局麻附加静脉镇静增加发生率。恶心、呕吐、眩晕、支气管痉挛、延迟苏醒是常见麻醉相关再入院的原因。
31. 全麻后的病人何时能进行机动车驾驶？
当前建议全麻或接受静脉镇静的病人，术后以后的24-48h不操作重型机械，包括开车。在自己或他人看来已经完全恢复的病人，轻微精神运动性障碍或定向力障碍是持续存在的，这些行为应该推迟到术后第二天。但与警告相反，术后调查发现有一些病人在术后24h驾驶车辆，甚至直接开车回家。
病人也可能因为中枢神经系统紊乱或手术本身会有脚步较轻的感觉，甚至跌到。其中的一些和意识混乱或精神状态的变化有关。还有其他原因如眩晕或疼痛。也希望未来的麻醉药不再有后续的，潜在中枢神经系统功能不全的危险。
32.门诊手术病人术后恢复中心的地位是什么？
一些手术后，病人会有口服阿片类药物不能控制的术后疼痛。所以他们需要一些技术性的护理观察或特殊护理，这可以在急救医院外获得，并对病人和家人来说更便宜，舒适。带着这种理念，恢复护理医疗机构的概念诞生了，出现了一种新的住院病人术后监护单位。这种模式整合了需要过夜观察的门诊手术病人或延伸的出院后服务。例如子宫切除术，腹腔镜胆囊切除术，shoulder repairs, 乳房切除术。如果这种形式也不能得到，可使用合适的家庭服务包括控制疼痛的新模式也能让病人免去术后的过夜住院观察。
33.门诊手术质量能持续提高吗？
为了确保病人满意的服务质量，麻醉医生应该在术后一天对所有病人电话追踪服务。有些机构还有两项另外的服务，一个是手术当天夜里和术后一周。术后访问卡应该邮寄给病人，询问整个经历。要有空白地方让病人填写副作用或不良反应。依靠外科医生提供精确并发症反馈信息是不可靠的。因此，追踪服务机制必须进行，以发现和确认需要补救措施。
《完》
