Optimal Anesthetic Techniques

The optimal anesthetic technique in the ambulatory setting would provide for excellent operating conditions, rapid "fast-track" recovery without postoperative side effects or complications, and a high degree of patient satisfaction. In addition to increasing the quality and decreasing the cost of anesthetic services, the ideal anesthetic technique would also improve operating room efficiency (e.g., turnover times) and provide for an earlier discharge home. Local anesthesia with intravenous sedation (i.e., MAC techniques), regional (peripheral) blocks, spinal anesthesia, and general anesthesia are all commonly used for ambulatory surgery. However, opinions differ regarding the "best" anesthetic technique, even for superficial surgical procedures. ^{[369] [478] [479] [480] [481] [482] [483] [484] [485] [486] [487] [488] [489]} Rather than simply generalizing about the best anesthetic technique for ambulatory surgery, it would be better to individually analyze each surgical procedure.^[490]

In the current cost-conscious environment, it is important to also examine the impact of anesthetic techniques on the perioperative process because prolonged recovery times and reduced efficiency and productivity contribute to the increased cost of surgical care.^{[431] [432]} In addition, patient satisfaction with the perioperative experience and quality of recovery is improved when the anesthetic technique chosen for the procedure is associated with a low incidence of postoperative side effects. For example, the routine use of prophylactic antiemetic drugs during general anesthesia has been found to increase patient satisfaction in "at-risk" outpatient surgical populations.^[152] Furthermore, the use of local anesthetic infiltration or peripheral nerve blocks, or both, decreases postoperative pain after ambulatory surgery procedures irrespective of the anesthetic technique.^{[491] [492] [493]}

The time required to achieve a state of home readiness (i.e., "fitness" for discharge home) is influenced by a wide variety of surgical and anesthetic factors.^{[494] [495]} However, the major contributors to a delay in discharge after ambulatory surgery are nausea, vomiting, dizziness, pain, and prolonged sympathetic or motor blockade (or both). Although the incidence of PONV can be decreased by the use of prophylactic antiemetic drugs,^[491] it remains a common side effect after general anesthesia and prolongs discharge after ambulatory surgery. ^[150] The primary factor delaying discharge after spinal anesthesia is recovery from the residual motor and sympathetic blockade, which contributes to delayed ambulation and an inability to void. These side effects can be minimized by use of the so-called minidose lidocaine-fentanyl spinal anesthetic technique.^{[487] [489]} Other concerns with spinal anesthesia include back pain, post-dural puncture headache, and transient radicular irritation.^{[496] [497]} Although MAC is associated with the lowest incidence of postoperative side effects, ^{[431] [432]} the possibility of transient nerve palsy is a concern when peripheral nerve block techniques are used.^{[498] [499] [500]} Another issue relates to the fact that many patients simply prefer to "be asleep during the operation."

Use of the modern anesthetics (e.g., propofol, sevoflurane, desflurane) in combination with antiemetic prophylaxis with nonopioid analgesic techniques can achieve recovery times that compare favorably with MAC techniques ( Table 68-11 ).^{[318] [501] [502]} These studies demonstrated that outpatients undergoing hernia repair and breast surgery were able to ambulate within 30 minutes and were discharged within 60 minutes. Avoidance of tracheal intubation by using an LMA or a facemask also facilitates a fast-track recovery. When tracheal intubation is required (e.g., laparoscopic procedures, risk factors for aspiration [e.g., diabetics, morbidly obese, esophageal dysfunction]), the use of minimally effective doses of a short-acting opioid analgesic (e.g., remifentanil) or sympatholytic (e.g., esmolol) drug, or both, can facilitate the early recovery process and allow patients to achieve earlier discharge times after ambulatory surgery.^{[119] [332] [503] [504]}

The cost savings associated with use of the newer anesthetic techniques are lost if institutional practices mandate minimum lengths of stay in the phase 1 unit (PACU) and do not permit fast-tracking of patients who emerge rapidly from anesthesia directly to the phase 2 (day-surgery ["step-down"]) unit. Claims of reduced total costs with earlier discharge are commonly based on

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The relationship between decreasing costs and bypassing the PACU ("fast-tracking") appears to be much closer because the major factor in recovery care cost relates to the peak number of patients admitted to the PACU at any given time.^[505] Fast-tracking can lead to the use of fewer nurses and a mix of less highly trained, lower-wage nursing aides and fully qualified recovery room nurses and therefore reduces "overtime" personnel costs for busy ambulatory surgery units. Shorter anesthesia times, the ability to bypass the PACU, and a decreased length of stay in the day-surgery unit will reduce total institutional costs.^[506] Studies have demonstrated that "fast-tracking" ambulatory surgery patients decreases the time to actual discharge ( Table 68-12 ).^{[507] [508]}

The combination of low cost and high patient satisfaction suggests that the highest-quality (cost/outcome) anesthetic may be achievable with a MAC technique, assuming that the surgical procedure is amenable to this anesthetic approach (e.g., superficial surgical and endoscopic procedures). However, the success of MAC techniques is dependent not only on the anesthesiologist but also on the skills of the surgeon in providing effective infiltration analgesia and gentle handling of tissues during the intraoperative period. Superficial operations can be performed under local anesthesia without any monitoring or intravenous adjuvants (so-called unmonitored local anesthesia) in situations in which the local anesthesia is able to provide complete analgesia and patients do not object to being awake and aware of events in the operating room. ^[509] In a prospective, randomized comparison of local infiltration with spinal and general anesthesia,^[510] surgeons in Sweden suggested that technical difficulties and patient pain were "more intense" during surgery under local anesthesia. This finding is consistent with an earlier report by Fairclough and colleagues.^[511] However, the researchers in Sweden concluded that "for many patients, local anesthesia can be recommended as the standard procedure for outpatient knee arthroscopy."^[510]