Initial emergency department mechanical ventilation strategies for COVID-19 hypoxemic respiratory failure and ARDS

Abstract

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging viral pathogen that causes the novel coronavirus disease of 2019 (COVID-19) and may result in hypoxemic respiratory failure necessitating invasive mechanical ventilation in the most severe cases.

Objective: This narrative review provides evidence-based recommendations for the treatment of COVID-19 related respiratory failure requiring invasive mechanical ventilation.

Discussion: In severe cases, COVID-19 leads to hypoxemic respiratory failure that may meet criteria for acute respiratory distress syndrome (ARDS). The mainstay of treatment for ARDS includes a lung protective ventilation strategy with low tidal volumes (4-8 mL/kg predicted body weight), adequate positive end-expiratory pressure (PEEP), and maintaining a plateau pressure of < 30 cm H₂O. While further COVID-19 specific studies are needed, current management should focus on supportive care, preventing further lung injury from mechanical ventilation, and treating the underlying cause.

Conclusions: This review provides evidence-based recommendations for the treatment of COVID-19 related respiratory failure requiring invasive mechanical ventilation.

Keywords: Acute respiratory distress syndrome; COVID-19; Lung protective strategy; Mechanical ventilation; Respiratory failure; SARS-CoV-2.

Fig. 1

An example of a plateau pressure, checked after an end inspiratory pause when inspiratory flow has reached zero. The plateau pressure is 30 cm H₂O, in a volume control mode with a set 420 mL (6 mL/kg PBW) tidal volume. The driving pressure is 15 cm H₂O (plateau pressure of 30 cm H₂O - PEEP of 15 cm H₂O). The driving pressure is related to the static compliance of the respiratory system (C_RS) by C_RS = Tidal Volume/Driving Pressure. In this patient the C_RS is low at 28 mL/cm H₂O.

Fig. 2

A representation of the relationship between compliance of the respiratory system (C_RS) and PEEP. If increasing PEEP improves recruitment, by aeration of previously non-aerated lung, then compliance will improve until the lungs are overdistended and compliance worsens.

Fig. 3

A recommended initial approach to COVID-19 related hypoxemic respiratory failure in the Emergency Department. Abbreviations: HFNC (high flow nasal cannula), NIPPV (non-invasive positive pressure ventilation), PBW (predicted body weight), V_T (tidal volume), P/F (PaO₂/FiO₂ ratio), IV (intravenous)