Long-Term Survival of Mechanically Ventilated Patients with Severe COVID-19: An Observational Cohort Study

Abstract

Background: Information is lacking regarding long-term survival and predictive factors for mortality in patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19) and undergoing invasive mechanical ventilation. We aimed to estimate 90-day and 180-day survival of patients with COVID-19 requiring invasive ventilation and to develop a predictive model for intensive care unit mortality.Methods: Retrospective, multicentre, national cohort study between March 8 and April 30, 2020 in 16 intensive care units (ICU) in Spain. Participants were consecutive adults who received invasive mechanical ventilation for COVID–19. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection detected in positive testing of a nasopharyngeal sample and confirmed by real time reverse-transcriptase polymerase chain reaction (rt-PCR). The primary outcomes were 90-day and 180-day survival after hospital admission. Secondary outcomes were length of ICU and hospital stay, and ICU and in-hospital mortality. A predictive model and a nomogram were developed to estimate the probability of ICU mortality. Results: 868 patients were included (median age, 64 years [interquartile range [IQR], 56-71 years]; 72% male). Severity at ICU admission, estimated by SAPS3, was 56 points [IQR 50-63]. Prior to intubation, 26% received some type of noninvasive respiratory support. The 90-day and 180-day survival rates were 69% (95% confidence interval [CI] 66%-72%) and 59% (95% CI 56%-62%) respectively. The predictive factors associated with ICU mortality were: age (odds ratio [OR] 1.049 [95% CI 1.032-1.066] per 1-year increase), SAPS3 (OR 1.025 [95% CI 1.008-1.041] per 1-point increase), neutrophil to lymphocyte ratio (OR 1.009 [95% CI 1.002-1.016]), a failed attempt of noninvasive positive pressure ventilation previous to orotracheal intubation(OR 2.131 [95% CI 1.279-3.550]), and use of selective digestive decontamination (OR 0.587 [95% CI 0.358-0.963]).Conclusion: The long-term survival of mechanically ventilated patients with severe COVID-19 reaches more than 50% and may help to provide individualized risk stratification and potential treatments.Trial registration: ClinicalTrials.gov Identifier: NCT04379258. Registered 10 April 2020 (retrospectively registered).