The Diagnostic And Therapeutic Value Of Bronchoscopy In COVID-19 Patients On Veno-venous Extracorporeal Membrane Oxygenator (ECMO) Support: A Single Center Experience. (preprint)

ABSTRACT

Introduction: Mechanically ventilated patients COVID-19 patients on veno-venous extracorporeal membrane oxygenation (VV-ECMO) support often require bronchoscopy for pulmonary toilet. However, bronchoscopy in these patients may lead to tracheobronchial bleeding from instrumentation and vial aerosolization. The aim of this study was to assess the indications, benefits, and complications of bronchoscopy in critically ill patients with COVID-19 on VV-ECMO. Methods: This was a single center observational cohort study comprising of adults with COVID-19 infection that required mechanical ventilation and VV-ECMO from January 1, 2019 to November 1, 2021 and needed bronchoscopy. The primary outcome was improvement in patient outcome defined as either in improvement in PaO2 levels or VV-ECMO parameters 6 hours after the procedure. Secondary outcomes included microbiological data from the BAL samples. Mann-Whitney U and χ2 tests were used to compare continuous and categorical variables, respectively. Wilcoxon rank sum test for comparing correlated non-parametric continuous data. The median difference was calculated using the Hodges-Lehman estimator. Results: A total of 89 bronchoscopies were performed in 44 patients with COVID-19 on VV-ECMO. Median (IQR) PaO2 was 64 (57-75) mmHg prior to bronchoscopy, whereas it was mildly improved to 70 (58-89) mmHg, 6 hours after the procedure [Hodges-Lehman median difference (95% CI) 4.5 (2.0 – 8.0) mm Hg, p <0.01]. There was no significant difference in VV-ECMO parameters before and after the procedure. 10 patients had different microorganisms in broncheo-alveolar lavage that were not diagnosed with tracheal aspirate. No patient developed new bleeding post bronchoscopy requiring interruption of anticoagulation. No proceduralist reported testing positive for COVID-19 up to 2 weeks post bronchoscopy. Conclusions: Bronchoscopy is a feasible and relatively safe procedure in COVID-19 patients on VV-ECMO and might be beneficial in select patients to improve oxygenation and tailor antibiotic therapy. Larger studies are required to evaluate the overall impact on patient’s recovery with serial bronchoscopies.