Introduction
The rapid outbreak of coronavirus disease 2019 (COVID-19), originating from severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection, is a public health emergency of international concern. Diagnosing COVID-19, treating its complications, and predicting how the disease will progress in different patients remains a challenge. The DRAGON project (IMI 2-call 21, #101005122) is drawing on new and existing data and sample collection efforts to carry out a detailed profiling of patients. In the Dragon consortium, Florence University, Italy and Centre Hospitalier Universitarie de Liege, Belgium have focused their research on the role of interventional pulmonology (IP) and bronchoalveolar lavage (BAL) sample collection in COVID-19. This document reflects the perspective of some of the Dragon research consortium collaborators on the utility of BAL in COVID-19.
Interventional pulmonology in patients with COVID-19 is required to manage complications (atelectasis, haemoptysis, pneumothorax, pleural effusions, etc), and to guide airways management (airway secretion management, intubation or tracheostomy guide). BAL in COVID-19 has been used to obtain samples for both cytology and microbiology purposes (detecting infections, differential diagnosis with other interstitial lung disorders, etc). If the role of IP in treating COVID-19 complications and guiding airway management is well established, the role of BAL in COVID-19 diagnosis and management has been questioned. Bronchoscopy is an aerosol generating procedure, and its routinely use in COVID-19 patients has been discouraged.1 However, avoiding bronchoscopy in COVID-19 patients expose physicians to risks of misdiagnosis and suboptimal treatment. BAL is a well-established minimally invasive technique that has an important diagnostic role and has been routinely used for decades for the diagnosis of infectious, neoplastic and non-neoplastic diffuse lung diseases. BAL clinical role in the diagnosis of respiratory infection is of utmost importance.2-5 Therefore, BAL has been used in many expert centres to manage COVID-19 and in several research protocols to investigate COVID-19 pathogenetic mechanisms.
We aimed to review the current evidence supporting the role of BAL in the diagnosis of COVID-19 infection, in the detection of coexisting infections, and in the understanding of COVID-19 features and pathogenetic mechanisms.