Characteristics, outcomes and global trends of respiratory support in patients hospitalized with COVID-19 pneumonia: a scoping review.

Radovanovic, Dejan; Santus, Pierachille; Coppola, Silvia; Saad, Marina; Pini, Stefano; Giuliani, Fabio; Mondoni, Michele; Chiumello, Davide A

INTRODUCTION To date, a shared international consensus on treatment of Coronavirus Disease 2019 (COVID-19) with invasive or non-invasive respiratory support is lacking. Patients' management and outcomes, especially in severe and critical cases, can vary depending on regional standard operating procedures and local guidance. EVIDENCE ACQUISITION Rapid review methodology was applied to include all the studies published on PubMed and Embase between December 15th 2019 and February 28th 2021, reporting in-hospital and respiratory support-related mortality in adult patients hospitalized with COVID-19 that underwent either continuous positive airway pressure (CPAP), non-invasive ventilation (NIV) or invasive mechanical ventilation (IMV). Only English language studies with ≥100 patients and reporting data on respiratory failure were included. Data on comorbidities, ventilatory parameters and hospital-related complications were registered. EVIDENCE SYNTHESIS Fifty-two studies (287359 patients - 57.5% males, mean age 64 years (range 24-98)) from 17 different countries were included in the final analysis. 33.3% of patients were hospitalized in intensive care units. 44.2% had hypertension, 26.1% had diabetes, and 7.1% a chronic respiratory disease. 55% of patients underwent respiratory support (36% IMV, 62% NIV and 2% CPAP). Without considering a study with the highest number of patients treated with NIV (n=96729), prevalence of NIV and CPAP use was 12.5% and 13.5% respectively. Globally, invasive and non-invasive approaches were heterogeneously applied. In-hospital mortality was 33.7%, and IMV-related mortality was 72.6% (range: 4.3%-99%). Specific mortality in patients treated with CPAP or NIV was available for 53% of studies, and was 29% (range: 7.2%-100%). The median length of hospital stay was 13 days (range: 6-63). The most frequent hospital-related complication was acute kidney injury being reported in up to 55.7% of enrolled patients. CONCLUSIONS Global employment of respiratory supports and related outcomes are very heterogeneous. The most frequent respiratory support in patients with COVID-19 pneumonia is IMV, while NIV and CPAP are less frequently and equally applied, the latter especially in Europe, while data on NIV/CPAP-related mortality is often under-reported. Integrated and comprehensive reporting is desirable and needed to construct evidence-based recommendations.