Clinical characteristics and day-90 outcomes of 4244 critically ill adults with COVID-19: a prospective cohort study

Abstract

Purpose: To describe acute respiratory distress syndrome (ARDS) severity, ventilation management, and the outcomes of ICU patients with laboratory-confirmed COVID-19 and to determine risk factors of 90-day mortality post-ICU admission.

Methods: COVID-ICU is a multi-center, prospective cohort study conducted in 138 hospitals in France, Belgium, and Switzerland. Demographic, clinical, respiratory support, adjunctive interventions, ICU length-of-stay, and survival data were collected.

Results: From February 25 to May 4, 2020, 4643 patients (median [IQR] age 63 [54-71] years and SAPS II 37 [28-50]) were admitted in ICU, with day-90 post-ICU admission status available for 4244. On ICU admission, standard oxygen therapy, high-flow oxygen, and non-invasive ventilation were applied to 29%, 19%, and 6% patients, respectively. 2635 (63%) patients were intubated during the first 24 h whereas overall 3376 (80%) received invasive mechanical ventilation (MV) at one point during their ICU stay. Median (IQR) positive end-expiratory and plateau pressures were 12 (10-14) cmH2O, and 24 (21-27) cmH2O, respectively. The mechanical power transmitted by the MV to the lung was 26.5 (18.6-34.9) J/min. Paralyzing agents and prone position were applied to 88% and 70% of patients intubated at Day-1, respectively. Pulmonary embolism and ventilator-associated pneumonia were diagnosed in 207 (9%) and 1209 (58%) of these patients. On day 90, 1298/4244 (31%) patients had died. Among patients who received invasive or non-invasive ventilation on the day of ICU admission, day-90 mortality increased with the severity of ARDS at ICU admission (30%, 34%, and 50% for mild, moderate, and severe ARDS, respectively) and decreased from 42 to 25% over the study period. Early independent predictors of 90-day mortality were older age, immunosuppression, severe obesity, diabetes, higher renal and cardiovascular SOFA score components, lower PaO2/FiO2 ratio and a shorter time between first symptoms and ICU admission.

Conclusion: Among more than 4000 critically ill patients with COVID-19 admitted to our ICUs, 90-day mortality was 31% and decreased from 42 to 25% over the study period. Mortality was higher in older, diabetic, obese and severe ARDS patients.

Keywords: Acute respiratory distress syndrome; COVID-19; Mechanical ventilation; Mortality risk factor; Outcome.

Conflict of interest statement

MS reported personal fees from Getinge, Drager, and Xenios, outside the submitted work. AD reports personal fees from Medtronic, grants, personal fees and non-financial support from Philips, personal fees from Baxter, personal fees from Hamilton, personal fees and non-financial support from Fisher & Paykel, grants from French Ministry of Health, personal fees from Getinge, grants and personal fees from Respinor, grants and non-financial support from Lungpacer, outside the submitted work. AM reported personal fees from Faron Pharmaceuticals, Air Liquid Medical Systems, Pfizer, Resmed and Draeger and grants and personal fees from Fisher and Paykel and Covidien, outside this work. MD reported personal fees from Lungpacer. AK reported personal fees from Aspen, Aguettant and MSD. No other disclosures were reported.

Figures

Fig. 1

Flowchart of patients screening and inclusion. ICU intensive care unit

Fig. 2

Kaplan–Meier survival estimates during the 90 days following ICU admission, according to A) Acute Respiratory Distress Syndrome Severity in patients on invasive mechanical ventilation or non-invasive ventilation at Day-1; B) age categories; C) ARDS severity progression within 7 days in patients with mild ARDS at Day-1*; D) ARDS severity progression within 7 days in patients with moderate ARDS at Day-1. *Only patients alive at day-7 were included in this analysis. ICU intensive care unit