Abstract
Objective
Previous studies in non-COVID acute respiratory distress syndrome (ARDS) demonstrated that hypoxemic patients treated with high-flow nasal cannula (HFNC) and those receiving invasive mechanical ventilation (MV) have comparable biomarker profiles. We aimed to determine whether these findings apply to COVID-19 ARDS and to compare biomarker profiles between COVID-19 and non-COVID ARDS.Design
Prospective cohort study.Setting
Medical-surgical intensive care units of two tertiary hospitals.Patients
Adults with COVID-19 ARDS managed with MV or HFNC and a previously published non-COVID ARDS cohort.Intervention
None.Main variables of interest
Baseline demographics, clinical, respiratory hemodynamic, and laboratory variables were collected. Plasma concentrations of epithelial lung injury markers (receptor for advanced glycation end products [RAGE], surfactant protein D [SP-D]), endothelial injury marker (angiopoietin-2 [Ang-2]), and inflammatory cytokines (IL-6 and IL-8) were measured.Results
A total of 135 patients with COVID-19 were included (22 MV, 113 HFNC); 53 [46.9%] HFNC patients subsequently required intubation. In matched analyses, biomarker concentrations did not differ significantly between MV and HFNC groups. Within the HFNC cohort, higher RAGE concentrations were associated with HFNC failure [cutoff ≥ 3338.5 pg/mL; adjusted OR∼15 (95%CI 1.9-65.0)]. Patients with HFNC failure exhibited biomarker profiles similar to those of invasively ventilated patients. Comparison according to ARDS etiology showed higher RAGE and IL-6 concentrations in COVID-19 ARDS, whereas SP-D and Ang-2 concentrations were higher in non-COVID ARDS.Conclusions
Patients with COVID-19 acute hypoxemic respiratory failure managed with HFNC or MV exhibited broadly similar epithelial, endothelial and inflammatory biomarker profiles. These findings support further investigation into the inclusion of non-intubated patients fulfilling ARDS criteria apart from PEEP requirements within the ARDS spectrum. Differences in biomarker profiles between COVID-19 and non-COVID ARDS suggest biological heterogeneity according to ARDS etiology. Elevated RAGE concentrations were associated with HFNC failure and may reflect the prognostic relevance of epithelial injury in COVID-19 ARDS.