Preoperative assessment of the risk for multiple complications after surgery

The association between preoperative patient characteristics and the number of major postoperative complications after a major operation is not well defined.

In a retrospective, single-center cohort of 50,314 adult surgical patients, we used readily available preoperative clinical data to model the number of major postoperative complications from none to ≥3. We included acute kidney injury; prolonged stay (>48 hours) in an intensive care unit; need for prolonged (>48 hours) mechanical ventilation; severe sepsis; and cardiovascular, wound, and neurologic complications. Risk probability scores generated from the multinomial logistic models were used to develop an online calculator. We stratified patients based on their risk of having ≥3 postoperative complications.

Patients older than 65 years (odds ratio 1.5, 95% confidence interval, 1.4-1.6), males (odds ratio 1.2, 95% confidence interval, 1.2-1.3), patients with a greater Charlson comorbidity index (odds ratio 3.9, 95% confidence interval, 3.6-4.2), patients requiring emergency operation (odds ratio 3.5, 95% confidence interval, 3.3.-3.7), and patients admitted on a weekend (odds ratio 1.4, 95% confidence interval, 1.3-1.5) were more likely to have ≥3 postoperative complications than they were to have none. Patients in the medium- and high-risk categories were 3.7 and 6.3 times more likely to have ≥3 postoperative complications, respectively. High-risk patients were 5.8 and 4.4 times more likely to die within 30 and 90 days of admission, respectively.

Readily available, preoperative clinical and sociodemographic factors are associated with a greater number of postoperative complications and adverse surgical outcomes. We developed an online calculator that predicts probability of developing each number of complications after a major operation.