Temporal patterns of postoperative complications.

HYPOTHESIS A variety of major complications occur after intra-abdominal operations. Knowledge of when specific complications occur during the postoperative period would be useful in their diagnosis, prevention, and management. Our aim was to determine the incidence of major complications during specific postoperative intervals. DESIGN One thousand twenty-one patients undergoing intra-abdominal operations were studied postoperatively as part of a randomized clinical trial. Thirteen defined major complications were sought at the following specific intervals: less than 1, 1 through 3, 4 through 7, and 8 through 30 days after the operation. SETTING Cooperative trial from 15 Veterans Affairs medical centers. INTERVENTIONS Intra-abdominal aortic, gastric, biliary, and colonic procedures. MAIN OUTCOME MEASUREMENTS Major postoperative complications. RESULTS Four hundred thirty-five major complications were diagnosed within 30 days of the patients' being operated on. Seventy-four (17%) occurred within 1 day, 185 (43%) between 1 and 3 days, 72 (17%) between 4 and 7 days, and 104 (24%) between 8 and 30 days. Three deaths (8%) occurred within 1 day, 3 (8%) in 1 through 3 days, 4 (11%) in 4 through 7 days, and 27 (73%) in 8 through 30 days. The greatest risk of hypotension (43%), myocardial infarction (47%), and respiratory depression (55%) was within 1 day. The highest incidence of congestive heart failure (46%), pulmonary embolus (50%), and respiratory failure (76%) occurred at 1 through 3 days. Pneumonia (38%) was most common at 4 through 7 days. Cerebrovascular accident (53%) and sepsis (71%) occurred preponderantly at 8 through 30 days. Renal failure had a bimodal distribution with maxima at 1 through 3 days (31%) and 8 through 30 days (56%). The risk of cardiac arrhythmia and gastrointestinal tract bleeding was similar throughout all intervals. CONCLUSIONS While major complications occur throughout the postoperative period, the highest incidence is 1 through 3 days after the operation. However, specific complications occur in the following distinct temporal patterns: early postoperative, several days after the operation, throughout the postoperative period, and in the late postoperative period. Knowledge of these patterns should aid clinical management.