Outpatient Anesthesia

INTRODUCTION

Ambulatory anesthesia is a rapidly growing field involving three distinct entities: outpatient anesthesia (the primary focus of this chapter), office-based anesthesia (OBA), and non–operating room anesthesia (NORA) (also see Chapter 38 ). The idea of outpatient anesthesia started over 100 years ago when an ambulatory surgical center (ASC) was opened in Iowa; 50 years later, the first modern ASC was opened in Phoenix, Arizona, in 1970. Since then, indications for outpatient surgery have expanded, and outpatient anesthesia has been performed in many different types of facilities. In 2014 over half of hospital visits (inpatient or ambulatory) that included invasive, therapeutic surgeries were performed in a hospital-owned ambulatory surgery setting.

The Society for Ambulatory Anesthesia (SAMBA) was founded in 1985 to become a resource for providers who practice in settings outside of hospital-based operating rooms. SAMBA periodically issues statements regarding the practice of ambulatory anesthesia and has published an evidence-based guide to the management of ASCs. The American Society of Anesthesiologists (ASA) issued guidelines for ambulatory anesthesia and surgery in 2003; these guidelines were reaffirmed in 2018.

Ambulatory Anesthesia Settings

In ambulatory surgery a patient is anticipated to come to the facility on the day of surgery, undergo a surgery or invasive procedure, and be discharged home on the same day (or within 23 hours). Ambulatory surgery can be performed in several different types of facilities, including an outpatient office, freestanding ASC, freestanding ASC with extended stay (less than 23 hours), ASC within a hospital complex, hospital operating room, and NORA locations ( Fig. 37.1 ). The capabilities at each facility will affect patient selection and the procedures performed.

PATIENT SELECTION

Careful selection and optimization of patients are essential for safe outpatient anesthesia. In addition, the type of facility should be appropriate for the procedure and patient comorbidities. For example, a patient with multiple medical comorbidities may be better suited for care in the outpatient surgery suite within the main operating room of a hospital or a NORA location versus an office-based practice. Other patients can safely undergo their procedure in a freestanding ASC or an OBA practice setting. The preoperative evaluation and optimization process should proceed in the same manner as a patient scheduled for inpatient surgery (also see Chapter 13 ). The ASA Practice Guidelines for Postanesthetic Care recommend that a responsible individual should accompany a patient home after surgery.

SURGERIES AND PROCEDURES

The most commonly performed ambulatory surgery procedures are listed in Box 37.1 . In addition, certain procedures are performed on an ambulatory basis over 90% of the time ( Box 37.2 ). The spectrum of ambulatory surgeries has been expanding, coincident with the substantial growth in equipment, techniques, and expertise in performing minimally invasive surgeries. More recently, freestanding ASCs have embarked on performing major joint surgeries, such as knee and hip arthroplasty, as an outpatient procedure. These programs use strict patient selection criteria and an anesthetic regimen that facilitates early mobility and adequate pain control. The success of an outpatient major joint program depends on a dedicated ASC team and a protocol that spans the perioperative period starting with patient selection (ideally, a medically stable, motivated patient), surgical scheduling, preoperative nutrition, patient education, discharge planning, and postoperative pain management and physical therapy regimen.