Histological findings of tracheal samples from COVID‐19 positive critically ill mechanically ventilated patients

Abstract

Objectives This study examines the histological findings of tracheal tissue samples obtained from COVID‐19 positive mechanically ventilated patients, to assess the degree of tracheal inflammation/ulceration present. Design and participants Retrospective single‐centre observational cohort study. All patients admitted to Adult Intensive Care Unit (AICU) with COVID‐19 infection, requiring mechanical ventilation and surgical tracheostomy between 1 April and 1 May 2020, were included ( Group 1 ). Tracheal windows excised at tracheostomy underwent histological analysis. Comparison was made with: tracheal windows from COVID‐19 positive AICU ventilated patients admitted between 1 January and 1 March 2021 ( Group 2 ); tracheal windows from COVID‐19 negative AICU ventilated patients ( Group 3 ); and, tracheal autopsy samples from COVID‐19 positive patients that died without undergoing prolonged mechanical ventilation ( Group 4 ). Results G roup 1 demonstrated mild/moderate inflammation (tracheitis) in nearly all samples (15/16, 93.8%), with infrequent micro‐ulceration (2/16, 12.5%). G roup 2 demonstrated similar mild/moderate inflammation in all samples (17/17, 100%), with no ulceration. Histological findings of Groups 1 and 2 COVID‐19 positive patients were similar to Group 3 COVID‐19 negative patients, which demonstrated mild/moderate inflammation (5/5, 100%), with uncommon superficial erosion (1/5, 20%). Group 4 demonstrated mild chronic inflammation or no significant inflammation, with uncommon micro‐ulceration (1/4, 25%). Conclusions Severe tracheal inflammation was not demonstrated in mechanically ventilated COVID‐19 positive patients at the level of the second/third tracheal rings, at the stage of disease patients underwent tracheostomy. Histological findings were similar between mechanically ventilated COVID‐19 positive and negative patients. Tracheal ulceration may be a feature of early or severe COVID‐19 disease.