Detection of residual pulmonary alterations with lung ultrasound and effects on postoperative pulmonary complications for patients with asymptomatic SARS-CoV-2 infection undergoing surgeries

Background: For patients with a clinical course of active SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection, there may be a higher risk of perioperative complications. Our main objective is to detect the residual pulmonary alterations in asymptomatic patients after SARS-CoV-2 infection undergoing surgery and determine their relationship with the clinical course of SARS-CoV-2 infection. The secondary aim is to investigate whether the presence of residual pulmonary alterations have any affects on the severity of postoperative pulmonary complications. Methods: After approval by the Hospital's Ethical Committee, this prospective observational study included consecutive patients (n=103) undergoing various surgical procedures and anesthetic techniques with a history of past SARS-CoV-2 infection. On the day of surgery these patients remained asymptomatic and the polymerase chain reaction (PCR) test for SARS-CoV-2 was negative. The history, physical findings, and clinical course of SARS-CoV-2 infection were recorded. Lung ultrasound was performed before surgery to evaluate the possible residual pulmonary alterations (>= 3 B-lines and pleural thickening), along with determitation of pulmonary static compliance values during surgery. Postoperative pulmonary complications were collected during hospital stay. Results: 24.27% (n=25) patients presented >= 3 B-lines, and 28% (n=29) patients presented pleural thickening. For 15 patients (21.7%) the pulmonary compliance was < 40 mL/cm H2O. Patients with pleural thickening had a higher incidence of pneumonia, acute respiratory syndrome distress, a need for vasoactive drugs and required more days of hospitalization during SARS-CoV-2 infection (p= 0.004, 0.001, 0.03, 0.00 respectively). Patients with >= 3 B-lines needed more days in an intensive care unit and vasoactive drugs during SARS-CoV2 infection (p= 0.04, 0.004 respectively). Postoperative pulmonary complications were observed in 5.8% (n=6) of the patients, and were more frequent in the presence of both, >= 3 B-lines and pleural thickening (p= 0.01). Conclusions: In asymptomatic post-COVID-19 patients, pathological findings detected by lung ultrasound before surgery are associated with the severity of the SARS-CoV2 infection and resulted in more postoperative pulmonary complications. In these patients, the incidence of postoperative pulmonary complications appears similar to that described in the surgical population before the pandemic.