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。 |