Mechanical ventilation parameters in critically ill COVID-19 patients: a scoping review

Abstract

Background The mortality of critically ill patients with COVID-19 is high, particularly among those receiving mechanical ventilation (MV). Despite the high number of patients treated worldwide, data on respiratory mechanics are currently scarce and the optimal setting of MV remains to be defined. This scoping review aims to provide an overview of available data about respiratory mechanics, gas exchange and MV settings in patients admitted to intensive care units (ICUs) for COVID-19-associated acute respiratory failure, and to identify knowledge gaps. Main text PubMed, EMBASE, and MEDLINE databases were searched from inception to October 30, 2020 for studies providing at least one ventilatory parameter collected within 24 h from the ICU admission. The quality of the studies was independently assessed using the Newcastle–Ottawa Quality Assessment Form for Cohort Studies. A total of 26 studies were included for a total of 14,075 patients. At ICU admission, positive end expiratory pressure (PEEP) values ranged from 9 to 16.5 cm of water (cmH2O), suggesting that high levels of PEEP were commonly used for setting MV for these patients. Patients with COVID-19 are severely hypoxemic at ICU admission and show a median ratio of partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2) ranging from 102 to 198 mmHg. Static respiratory system compliance (Crs) values at ICU admission were highly heterogenous, ranging between 24 and 49 ml/cmH2O. Prone positioning and neuromuscular blocking agents were widely used, ranging from 17 to 81 and 22 to 88%, respectively; both rates were higher than previously reported in patients with “classical” acute respiratory distress syndrome (ARDS). Conclusions Available data show that, in mechanically ventilated patients with COVID-19, respiratory mechanics and MV settings within 24 h from ICU admission are heterogeneous but similar to those reported for “classical” ARDS. However, to date, complete data regarding mechanical properties of respiratory system, optimal setting of MV and the role of rescue treatments for refractory hypoxemia are still lacking in the medical literature.

COVID-19 pneumonia: pathophysiology and management

“…[ 5 ]. Consequently, the respiratory approach, in terms of applied pressures, became somewhat less aggressive, even though COVID-19 was still largely managed following the strategies employed in the classical forms of ARDS [ 52 ].…”

Ventilator-Associated Pneumonia in Patients with COVID-19: A Systematic Review and Meta-Analysis

“…Duration of IMV in patients with COVID-19 and admitted to ICU is often relatively long [ 1 ]. The clinical course of patients with the most severe form of COVID-19 in ICU may be complicated by the need for extracorporeal membrane oxygenation [ 8 ]. Other factors, such as the lung damage itself and the use of immunomodulant therapies (e.g., corticosteroids, anti-il-6 drugs) may also increase the risk of VAP in these cohorts of patients [ 9 ].…”

Incidence and Practice of Early Prone Positioning in Invasively Ventilated COVID-19 Patients—Insights from the PRoVENT-COVID Observational Study

“…Indeed, these patients often have severe hypoxemia. Additionally, consolidation may behave as focal lesions [6,7], which is another reason to apply prone positioning early after the start of invasive ventilation [8]. Last but not least, hypoxemia could also be a consequence of pulmonary embolism, for which higher PEEP is not helpful.…”