Patient(16) COVID-19(15) SARS-CoV-2(12) outcome(9) surgery(9) detect(8) hospital(8) respiratory(8) Mortality(8) pandemic(7) detection(7) Surgical Procedure(6) male(6) postoperative(6) high risk(5) polymerase chain reaction(5) reverse transcriptase(5) patients with COVID-19(5) surgical(5) Observational cohort study(5) Viral(5) Chain Reaction(5) virus(5) 95% confidence interval(5) Elective surgery(5) complications(5) clinical(5) evaluate(4) identify(4) tissue(4)