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. TRIAL REGISTRATION: clinicaltrials.gov (NCT04922931). June 21, 2021. "Retrospectively registered".

Lung Ultrasound Abnormalities in Patients Without Pulmonary Pathology Prior to Surgery.

Background: The occurrence of lung ultrasound abnormalities in patients without lung disease remains uncertain, while patients with respiratory disease often exhibit such abnormalities. Objectives: The primary aim was to identify pathological ultrasonographic pulmonary findings and their correlation with baseline diseases and static lung compliance in patients without any pre-existing respiratory conditions. Methods: This prospective observational study enrolled a series of surgical patients with no history of pulmonary pathology (n = 104). Baseline diseases and patients' physical status classification, based on the American Society of Anesthesiologists (ASA), were documented by reviewing medical records. Prior to surgery, a lung ultrasound was performed to assess pulmonary changes. During surgery with general anesthesia, static lung compliance was measured. The Spearman correlation coefficient was employed to determine the correlation between the two variables. Results: Twenty-four patients (23.07%) exhibited 1 - 2 B-lines in certain lung fields. Seven patients (6.7%) had an ultrasound B-line score > 0 (indicating ≥ 3 B-lines). Among these patients, the average number of lung fields with ≥ 3 B-lines was 3.71 ± 2.43. Patients with systemic diseases (ASA ≥ 2) displayed a higher number of B-lines compared to ASA I patients (P-value = 0.039). Pleural irregularities were found in 10 patients (9.6%), while atelectasis and pleural effusion were observed in five (4.8%) and four (3.8%) patients, respectively. The mean lung compliance value was 56.78 ± 15.33. No correlation was observed between the total score of the B-lines and lung compliance (Spearman's correlation: rho = -0.028, P-value = 0.812). Conclusions: Patients without pulmonary pathology may exhibit ultrasound pulmonary abnormalities, which tend to increase with higher ASA scores and do not appear to have a correlation with static lung compliance.