Perioperative Mortality of the COVID-19 Recovered Patient Compared to a Matched Control: A Multicenter Retrospective Cohort Study

Surgical procedures performed on patients with recent exposure to COVID-19 infection have been associated with increased mortality risk in prior studies. Accordingly, elective surgery is often delayed after infection. We aimed to compare 30-day hospital mortality and postoperative complications (acute kidney injury, pulmonary complications) of surgical patients with a prior COVID-19 infection, to a matched cohort of patients without known prior COVID-19. We hypothesized that COVID-19 exposure would be associated with an increased mortality risk.In this retrospective observational cohort study, patients presenting for elective inpatient surgery across a multicenter cohort of academic and community hospitals from April 2020 to April 2021 who had previously tested positive for COVID-19 were compared to controls who had received at least one prior COVID-19 test but without a known prior COVID-19 positive test. We matched cases based on anthropometric data, institution, and comorbidities. Further, we analyzed outcomes stratified by timing of a positive test result in relation to surgery.30-day mortality occurred in 229/4951 (4.6%) of COVID-19 exposed patients and 122/4951 (2.5%) controls. Acute kidney injury was observed in 172/1814 (9.5%) of exposed patients and 156/1814 (8.6%) controls. Pulmonary complications were observed in 237/1637 (14%) of exposed patients and 164/1637 (10%) controls. COVID-19 exposure was associated with an increased 30-day mortality risk (adjusted odds ratio 1.63, 95% CI 1.38-1.91), an increased risk of pulmonary complications (1.60, 1.36-1.88), but not associated with an increased risk of acute kidney injury (1.03, 0.87-1.22). Surgery within 2 weeks of infection was associated with a significantly increased risk of mortality and pulmonary complications, but that effect was non-significant after 2 weeks.Patients with a positive test for COVID-19 prior to elective surgery early in the pandemic have an elevated risk of perioperative mortality and pulmonary complications, but not acute kidney injury as compared to matched controls. The span of time from positive test to time of surgery affected the mortality and pulmonary risk, which subsided after 2 weeks.