Anesthetic management in ambulatory surgery is based on the SAMBA (Society for Ambulatory Anesthesia) S.A.F.E. principles . S.A.F.E. is an acronym that stands for short-acting, fast-emergence anesthetic. General, regional, combined regional/general, and monitored anesthesia care are all compatible with rapid patient discharge. An important consideration is that the anesthetic plan be compatible with patient expectations, surgical needs, and patient-specific factors. Many patients have a preconceived notion that general anesthesia implies delayed emergence and long recovery. These same patients may not appreciate, for example, the delay in discharge that can be associated with time needed for return of motor or bladder function after neuraxial (spinal, epidural) blockade. Patients should participate in the anesthetic planning where appropriate, with their concerns specifically addressed in the preoperative discussion

General, regional, combined regional/general, monitored anesthesia care, and local anesthesia are all compatible with rapid patient discharge. However, anesthetic plan should be compatible with patient expectations. Many patients have a preconceived notion that general anesthesia implies delayed emergence and long recovery. These same patients may not appreciate, for example, the delay to discharge that can be associated with time needed for the return of motor or bladder function after neuraxial blockade.

Generally speaking, short-acting anesthetic agents are better suited to rapid recovery. Midazolam is preferable to diazepam, propofol to thiopental, and bupivacaine or lidocaine to tetracaine. The inhaled potent agents are all similar in their clinical profiles provided that depth is titrated appropriately, although desflurane, due to its low blood solubility, likely has some clinical advantage in subgroups of patients such as the morbidly obese. In this regard, a processed EEG, such as BIS or SEDLine monitors, may have some utility as a guide to titration of anesthetic depth in order to avoid overdose of agents, which may prolong emergence or recovery.

Adequate postoperative analgesia is of paramount importance. In the absence of effective regional anesthesia, hydromorphone, morphine, and fentanyl are all acceptable opioid options in the intraoperative period. One caveat is that fentanyl is short-acting and may necessitate more aggressive loading with long-acting analgesic agents in the PACU or by mouth at home. Using several analgesics that work by different mechanisms, known as multimodal analgesia may help to reduce narcotic requirements and related side-effects. Analgesia options in selected patients include low-dose ketamine, intravenous ketorolac, acetaminophen, wound infiltration by local anesthetic, or via single-shot nerve block or continuous catheter.

Postoperative nausea and vomiting (PONV) is one of the major reasons for delayed discharge or unplanned admission after elective surgery. In light of the availability of safe, efficacious, and inexpensive agents for PONV prophylaxis (see Chap. 7) there appears to be limited downside to a single dose of a 5HT-3 antagonist (e.g. ondansetron) for most patients. Multimodal PONV prophylaxis should be considered in patients at higher risk. High risk patients include those with prior history of PONV, motion sickness, females nonsmokers, and patients undergoing ear, eye, gynecologic, or abdominal surgery. A scopolamine patch, low-dose dexamethasone, 5HT-3 antagonist, and metoclopramide are likely to have fewer sedating effects than droperidol, prochlorperazine, or promethazine.

Ambulatory surgery patients and their families desire rapid discharge from the PACU to home. Facilities differ in their discharge criteria, but almost all have well-defined protocols. PACU is often divided into Phase I (immediate recovery with active, ongoing issues such as blood pressure control, pain, and hypoxia) and Phase II (imminently ready for discharge except for voiding, ambulation, or demonstration of oral intake). Some facilities will use established scoring systems like those of Aldrete to objectively manage patient flow and discharge. These scoring systems emphasize pain control and return to baseline neurologic, hemodynamic, and pulmonary function. Most facilities require patients to consume a light snack and beverage and reach reasonable pain control on oral medication prior to discharge. Some still require postoperative voiding while in many centers voiding is not a criterion, provided the patient is not at high risk of urinary retention, has access to support persons at home and can be transported to the ER in the event of a problem.

“ Fast-Tracking” after ambulatory surgery is a widely accepted practice which involves transferring patients from the operating room to the later stage recovery area (Phase II), by bypassing the early stage (Phase I). The success of fast-tracking depends upon appropriate modification of the anesthetic technique, to allow rapid emergence from anesthesia and the prevention of pain and PONV. Implementation of a fast-track program involves the use of clinical pathways that reduce hospital stay and ensure patient safety.