Timing of Intubation and ICU Mortality in Covid-19 Patients: A Preplanned Retrospective Analysis of 4198 Critically Ill Patients

Abstract Background Optimal time to intubate patients with SARS-CoV-2 pneumonia is controversial. Whereas some authors recommend trying noninvasive respiratory support before intubate, others argue that delaying intubation can cause patient-self-induced lung injury and worsen the prognosis. We hypothesized that delayed intubation would increase the risk mortality in COVID-19 patients. Methods This preplanned retrospective observational study used prospectively collected data from adult patients with COVID-19 and respiratory failure admitted to 73 intensive care units between February 2020 and March 2021. Patients with limitations on life support and those with missing data were excluded.We collected demographic, laboratory, clinical variables and outcomes.Intubation was classified as 1) Very early: before or at ICU admission; 2) Early: < 24 hours after ICU admission; or 3) Late: ≥24 hours after ICU admission. We compared the early group versus those intubated late, using chi-square tests for categorical variables and the Mann-Whitney U for continuous variables. To assess the relationship between early versus late intubation and mortality, we used multivariable binary logistic regression. Statistical significance was set at p<0.05. Results We included 4198 patients [median age, 63 (54‒71) years; 70.8% male; median SOFA score, 4 (3‒7); median APACHE score, 13 (10‒18)], and median PaO 2 /FiO 2 , 131 (100‒190)]; intubation was very early in 2024 (48.2%) patients, early in 928 (22.1%), and late in 441 (10.5%). ICU mortality was 30.2% and median ICU stay was 14 (7‒28) days. Although patients in the late group were younger [62 vs. 64, respectively, p<0.05] and had less severe disease [APACHE II (13 vs. 14, respectively, p<0.05) and SOFA (3 vs. 4, respectively, p<0.05) scores], and higher PaO2/FiO 2 at admission (116 vs. 100, respectively, p<0.05), mortality was higher in the late group than in the early group (36.9% vs. 31.6%, p<0.05). Late intubation was independently associated with mortality (OR1.83; 95%CI 1.35‒2.47). Conclusions Delaying intubation beyond the first 24 hours of admission in patients with COVID-19 pneumonia increases the risk of mortality. Trial registration : The study was retrospectively registered at Clinical-Trials.gov (NCT 04948242) on the 30 th June 2021.