Bacterial Superinfection Pneumonia in Patients Mechanically Ventilated for COVID-19 Pneumonia.

Pickens, Chiagozie O; Gao, Catherine A; Cuttica, Michael J; Smith, Sean B; Pesce, Lorenzo L; Grant, Rogan A; Kang, Mengjia; Morales-Nebreda, Luisa; Bavishi, Avni A; Arnold, Jason M; Pawlowski, Anna; Qi, Chao; Budinger, G R Scott; Singer, Benjamin D; Wunderink, Richard G

RATIONALE Current guidelines recommend patients with SARS-CoV-2 pneumonia receive empirical antibiotics for suspected bacterial superinfection based on weak evidence. Rates of ventilator-associated pneumonia (VAP) in clinical trials of patients with SARS-CoV-2 pneumonia are unexpectedly low. OBJECTIVES We conducted an observational single center study to determine the prevalence and etiology of bacterial superinfection at the time of initial intubation and the incidence and etiology of subsequent bacterial VAP in patients with severe SARS-CoV-2 pneumonia. METHODS Bronchoscopic bronchoalveolar lavage (BAL) fluid samples from all patients with SARS-CoV-2 pneumonia requiring mechanical ventilation were analyzed using quantitative cultures and a multiplex polymerase chain reaction panel. Actual antibiotic use was compared with guideline-recommended therapy. MEASUREMENTS AND MAIN RESULTS We analyzed 386 BAL samples from 179 patients with SARS-CoV-2 pneumonia requiring mechanical ventilation. Bacterial superinfection within 48 hours of intubation was detected in 21% of patients. 72 patients (44.4%) developed at least one VAP episode (VAP incidence rate 45.2/1000 ventilator days); 15 (20.8%) of initial VAPs were caused by difficult-to-treat pathogens. Clinical criteria did not distinguish between patients with or without bacterial superinfection. BAL-based management was associated with significantly reduced antibiotic use compared with guideline recommendations. CONCLUSIONS In patients with SARS-CoV-2 pneumonia requiring mechanical ventilation, bacterial superinfection at the time of intubation occurs in less than 25% of patients. Guideline-based empirical antibiotic management at the time of intubation results in antibiotic overuse. Bacterial VAP developed in 44% of patients and could not be accurately identified in the absence of microbiologic analysis of BAL fluid. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).