Postoperative complications and mortality in older patients having non-cardiac surgery at three Melbourne teaching hospitals

Abstract

Objective: To determine the incidence of postoperative complications, including 30-day mortality rate, and need for intensive care unit (ICU) admission in older patients after non-cardiac surgery.

Design and setting: Prospective observational study of all patients aged 70 years or older having elective and non-elective, non-cardiac surgery, and staying at least 1 night after surgery in one of three Melbourne teaching hospitals, June to September 2004.

Main outcome measures: Postoperative complications and 30-day mortality rate.

Results: 1102 consecutive patients were audited in mid 2004; 70% had pre-existing comorbidities. The 30-day mortality rate was 6%; 19% had postoperative complications; and 20% of patients spent at least 1 night in ICU. On multivariate analysis, preoperative factors associated with 30-day mortality included age (odds ratio [OR], 1.09 per year over 70 years; 95% CI, 1.04-1.13; P < 0.001); increasing severity of systemic disease (American Society of Anesthesiologists physical status classification) (OR, 2.53; 95% CI, 1.65-3.86; P < 0.001); and albumin level < 30 g/L (OR, 2.23; 95% CI, 1.09-4.57; P = 0.03). Postoperative factors associated with 30-day mortality were unplanned ICU admission (OR, 3.95; 95% CI, 1.63-9.55; P = 0.003); sepsis (OR, 2.75; 95% CI, 1.17-6.47; P = 0.02); and acute renal impairment (OR, 2.40; 95% CI, 1.06-5.41; P = 0.04). Thoracic surgery was the only surgical specialty significantly associated with mortality (OR, 3.96; 95% CI, 1.44-9.10; P = 0.008) in the multivariate analysis.

Conclusion: Older patients having surgery had high rates of comorbidities and postoperative complications, placing considerable demands on critical care services. Patient factors were often stronger predictors of mortality than the type of surgery.