Factors influencing unexpected disposition after orthopedic ambulatory surgery

To analyze whether patient characteristics, ambulatory facility type, anesthesia provider and technique, procedure type, and temporal factors impact the outcome of unexpected disposition after ambulatory knee and shoulder surgery.

Retrospective analysis of a national database.

Freestanding and hospital-based ambulatory surgery facilities.

Ambulatory knee and shoulder surgery cases from 1996 and 2006 were identified through the National Survey of Ambulatory Surgery. The incidence of unexpected disposition status was determined and risk factors for such outcome were analyzed.

Factors independently increasing the risk for unexpected disposition included procedures performed in hospital-based versus freestanding facilities [odds ratio (OR) 6.83 (95% confidence interval [CI] 4.34; 10.75)], shoulder versus knee procedures [OR 3.84 (CI 2.55; 5.77)], anesthesia provided by nonanesthesiology professionals and certified registered nurse-anesthetists versus anesthesiologists [OR 7.33 (CI 4.18; 12.84) and OR 1.80 (CI 1.09; 2.99), respectively]. Decreased risk for unexpected disposition was for procedures performed in 2006 versus 1996 [OR 0.15 (CI 0.10; 0.24)] and the use of anesthesia other than regional or general [OR 0.34 (CI 0.18; 0.68)].

The decreased risk for unexpected disposition associated with more recent data and with freestanding versus hospital-based facilities may represent improvements in efficiency, while the decreased odds for such disposition status associated with the use of other than general or regional anesthesia may be related to a lower invasiveness of cases. We found an increased risk of adverse disposition in cases where the anesthesia provider was a nonanesthesiology professional. No difference in this outcome was noted when an anesthesia care team provided care.