Since the establishment of the first ambulatory surgical centers (ASCs) in 1970, the number of these facilities and the volume of procedures physicians perform in them have increased substantially. In parallel, during this time, there has been a marked shift to the outpatient setting for many common, low-risk operations that do not require hospitalization or a postoperative stay of more than 24 hours. Since 1991, according to the Ambulatory Surgery Center Association, more surgical procedures have been performed in the outpatient than the inpatient setting in the United States, and outpatient procedures now represent more than three-quarters of all operations performed.1 Putative advantages of ASCs include more convenient scheduling, increased patient and surgeon satisfaction, and lower costs.1