The American Society of Anesthesiologists' Physical Status: Category V revisited

Study Objective: To determine the perioperative mortality and intraoperativ e morbidity according to operative procedure and postoperative period for A merican Society of Anesthesiologists' Physical Status (AA-PS) V category pa tients. Design: Retrospective chart review. Setting: University-affiliated medical center. Measurement and Main Results: The perioperative records of 111,051 consecut ive anesthetized patients, from 1990 to 1997 were retrospectively reviewed. Data were collected and analyzed to determine ASA-PS classification, perio perative mortality, intraoperative morbidity, mortality according to operat ive procedure,and mortality postoperatively for ASA-PS V patients. At the U niversity of Florida, 0.37% of our patients were ASA-PS V. Most had anesthe sia for abdominal (26.2%), cardiothoracic (27.9%), cranial (12.3%), or diag nostic procedures (11.6%). The overall mortality rate decreased in 1993-199 5 and 1995-1997, compared to 1990-1993, from 64.16 +/- 4.53 (+/- SD) to 46. 7 +/- 9.5 and 56.8 +/- 1.1, respectively. The mortality rate decreased in t he immediate postoperative period from 15.7 +/- 5.1 to 4.6 +/- 1.5 and 4.1 +/- 2.8 intraoperatively, and from 42.5 +/- 1.8% to 22.1 +/- 5.1 and 26.8 /- 1.8 within 24 hours postoperatively. The mortality rate increased from 0 +/- 0 to 7.4 +/- 3.9 and 15.5 +/- 4.9 (p < 0.05 for all), during the late postoperative period (>2 weeks, during hospitalization). Intraoperative mor bidity (untoward events) was significantly higher for ASA-PS V patients tha n for ASA-PS IV patients only in emergency cases (11.1 +/- 4.8% vs. 5.5 +/- 1.4%). Conclusions: The ASA-PS V classification is determined subjectively rather than objectively, and can be variable within its parameters, depending on t he individual interpretation of ASA classification patent population, cae s everity, surgical and anesthesia factors,and the year of the study. Even th ough immediate perioperative morality decreased in our patient population, late postoperative mortality increased during the same time period possibly demonstrating a shift in mortality time rather than ana absolute decrease in overall mortality. Although the ASA-PS V category was never intended to be a predictor of outcome, it correlates with perioperative mortality as we ll as or even better than other classifications of mortality and morbidity. The decreased mortality in the ASA-PS V patient population may be related to different factors, which are beyond the scope of this study. (C) 2000 by Elsevier Science Inc.