Effect of the COVID-19 Pandemic on Bronchoscopy Indication and Bronchial Microbiology

Background: Lockdowns and mask wearing have impacted infectious disease patterns during the COVID-19 pandemic. We investigated changes in the use of bronchoscopy and the results of routine microbiology in bronchial lavage. Methods: We included bronchoscopies from 2017-2021 at the LMU University Department of Pulmonology. In this abstract we present an initial cohort comparing bronchoscopies in 2017-2018 to the initial phase of the COVID-19 pandemic in 2020. Comparisons used chi-squared and Fischer’s exact tests in SPSS. Results: We analysed 480 bronchoscopies from before and 85 during the COVID-19 pandemic. Mean age: 62.6 y (±14.1) before vs. 55.2 y (±16.3) during the pandemic (p<0.001). Indication for bronchoscopy: secretions/atelectasis (n=122), suspected tumor (n=89) and intervention/therapy (n=80) before; suspected tumor (n=30), respiratory deterioration after lung transplant (n=19) and infection (n=7) during the pandemic. Staphylococcus aureus and Pseudomonas aeruginosa were common in both groups. Frequencies of EBV (p<0.001), CMV (p=0.003) and HHV6 (p<0.001) differed significantly. Conclusion: There were clinically relevant differences in the use of bronchoscopy before vs. during the COVID-19 pandemic: pandemic patients were younger and interventions such as bronchial stenting and recanalisation less common. Bacterial results were similar but the frequency of common viruses differed. The effect of lockdowns, mask wearing and social distancing on bronchial microbiology in patients with lung cancer or chronic lung disease will be investigated in further detail in this cohort. Clinical relevant differences may support continued mask wearing in some high-risk situations post-pandemic.