key: cord-0980309-env1lyav authors: Ward, Patrick Alexander; Collier, Jonathan Marc; Weir, Justin; Osborn, Michael; Hanley, Brian; Smellie, William James Buchanan title: Histological findings of tracheal samples from COVID‐19 positive critically ill mechanically ventilated patients date: 2021-10-18 journal: Clin Otolaryngol DOI: 10.1111/coa.13872 sha: f0eceb6312388ed65040c06965a2c84b9594274a doc_id: 980309 cord_uid: env1lyav 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. The degree of tracheal inflammation/ulceration present in critically ill mechanically ventilated (MV) patients with coronavirus disease 2019 (COVID-19) is unknown. Routine tracheal inspection using a bronchoscope is relatively contraindicated due to the perceived risk of viral aerosolisation. However, clinically observed severe laryngo-tracheitis has been described in this patient population, 1,2 with one study reporting 47% full-thickness tracheal erosions or tracheo-oesophageal fistulae, based upon radiological and/ or bronchoscopic evaluation. 3 Tracheal inflammation is a recognised complication of prolonged MV 4 ; however, there is a rising number of case reports indicating increased incidence of pneumothorax, pneumomediastinum and subcutaneous emphysema ('barotrauma') in COVID-19 positive critically ill patients. 5 Notably, these potentially life-threatening complications appear to be more common in patients in whom severe tracheal inflammation/ulceration is present. 3 The aim of this study was to investigate the frequency and degree of tracheal inflammation/ulceration, by histological analysis of tracheal tissue samples obtained at surgical tracheostomy (ST) and at autopsy in critically ill patients with COVID-19. To our knowledge, there is currently no existing published data on tracheal histology in live COVID-19 patients. This retrospective observational cross-sectional study was con- • This is the first study to examine histology in live COVID-19 positive mechanically ventilated patients. The minor degree of tracheal inflammation/ulceration found is not consistent with more severe changes reported in previous bronchoscopic and radiological studies. Descriptive statistics were determined for all variables, using SPSS ® version 22 IBM ® , Chicago, IL, USA. A similar degree of mild/moderate tracheal inflammation was ob- Sixteen patients underwent MV and ST [median (IQR) age 54 (9.5); male gender 12/16 (75%)]. All TWs were made available for histological analysis (Table 1 ). In fifteen of the sixteen samples (15/16, 93.8%), diffuse mild/moderate inflammation (tracheitis) was observed, with neutrophils within the respiratory epithelium and active chronic inflammatory infiltrate in the submucosa ( Figure 1 ). In two of the samples, punctate micro-ulceration was also observed (2/16, 12.5%). The remaining sample (1/16, 6.25%) showed no significant acute inflammation, with only mild chronic inflammatory infiltrate, with scattered eosinophils but virtually no interstitial neutrophils. Eighteen patients underwent MV and ST; however, the TW from one patient was inadvertently discarded and therefore not available for analysis. This patient was omitted from the study, yielding sev- Five COVID-19 negative patients underwent MV and ST [median (IQR) age 57 (8); male gender 3/5 (60.0%)], with all TWs analysed (Table 1 ). All five patients underwent ST to assist with respiratory weaning (tracheal extubation was not attempted in any patients). Mild/moderate tracheitis was observed in all five samples Autopsy tracheal samples from four selected patients [median (IQR) age 70 (31.8); male gender 3/4 (75.0%)] were obtained and analysed for comparison (Table 1) A similar degree of mild/moderate tracheal inflammation was observed in the COVID-19 positive MV groups (Groups 1 and 2) , and The degree of tracheitis seen on histological analysis of TW samples from MV COVID-19 positive patients does not appear to be more severe than that found in COVID-19 negative MV patients at our in- This study was registered with Chelsea and Westminster Hospital The data that supports the findings of this study are available in the supplementary material of this article. Patrick Alexander Ward https://orcid.org/0000-0003-1925-9744 Emergency tracheal intubation in 202 patients with COVID-19 in Wuhan, China: lessons learnt and expert recommendations Multidisciplinary guidance for safe tracheostomy care during the COVID-19 pandemic: the NHS National Patient Safety Improvement Programme (NatPatSIP) Histopathology and ultrastructural findings of fatal COVID-19 infections in Washington State: a case series Additional supporting information may be found in the online version of the article at the publisher's website. How to cite this article Histological findings of tracheal samples from COVID-19 positive critically ill mechanically ventilated patients Laryngeal oedema associated with COVID-19 complicating airway management Appearance and management of COVID-19 laryngo-tracheitis: two case reports Evaluation of the incidence and potential mechanisms of tracheal complications in patients with COVID-19 Laryngeal injury and upper airway symptoms after oral endotracheal intubation with mechanical ventilation during critical care: a systematic review Pneumomediastinum following intubation in COVID-19 patients: a case series Abd El Baky MS. Serial histopathological tracheal changes from prolonged intubations The evolution of tracheal injury due to ventilatory assistance through cuffed tubes: a pathologic study