DETERMINANTS OF OUTCOME FOR PATIENTS IN THE MEDICAL INTENSIVE-CARE UNIT REQUIRING ABDOMINAL-SURGERY - A PROSPECTIVE, SINGLE-CENTER STUDY

Objective: To identify objective factors, available at the time of sur gical evaluation, associated with outcome for patients in the medical ICU undergoing abdominal surgery. Design: Single-center, prospective o bservational study. Setting: An academic tertiary care center. Patient s: The study included 1,617 consecutive patients in the medical ICU. I ntervention: Prospective patient surveillance and data collection. Mea surements: Patient demographics, severity of illness, organ system der angements, abdominal processes requiring surgery, and hospital mortali ty. Results: Sixty-seven patients in the medical ICU (4.1 percent) dev eloped an acute abdominal process potentially amenable to surgical int ervention. Eleven of these patients (16.4 percent) elected not to unde rgo surgery (mortality=100 percent). Forty-two of the 56 patients who underwent surgery survived (75.0 percent). Stepwise logistic regressio n analysis identified two independent objective predictors of mortalit y for this patient cohort (p<0.05): an organ system failure index (OSF I) >2 (adjusted odds ratio [AOR]=19.5; 95 percent confidence interval [CI], 7.4 to 51.5; p<0.001); and an APACHE II score >18 (AOR=9.4; CI=3 .1 to 28.3; p=0.03). The observed mortality following surgery was stra tified according to the presence or absence of these two factors: neit her present, 5.1 percent; APACHE II >18 present alone, 33 percent; OSF I >2 present alone, 60 percent; and both present, 88.9 percent (p<0.00 1). Surgical nonsurvivors and patients electing not to undergo surgery were similar without significant differences for demographics, severi ty of illness, or organ system derangements at the time of surgical ev aluation. Conclusions: The number of organ system derangements and the severity of illness, as assessed by APACHE II, appear to be useful di scriminators of outcome for patients in the medical ICU undergoing abd ominal surgery. These data suggest potential outcome predictors for th is selected group of patients in the ICU.