Evaluation of PEEand Prone Positioning in COVID-19 ARDS

Background: In face of the global spread of Corona Virus Disease (COVID)-19, best practice for mechanical ventilation in COVID-19 associated Acute Respiratory Distress Syndrome (ARDS) is intensely debated. Specifically, the rationale for high positive end-expiratory pressure (PEEP) and prone positioning in early COVID-19 ARDS has been questioned. Methods: The first 15 consecutive patients with COVID-19 associated respiratory failure transferred to a single ICU were assessed over the first 15 days of mechanical ventilation. Best PEEP was defined by maximal oxygenation, and was determined by decremental PEEP trials with monitoring of oxygenation, dead space fraction, airway pressures and trans-pulmonary pressures. In nine patients the impact of prone positioning on oxygenation was investigated. As well, the effects of invasive mechanical ventilation with PEEP and prone positioning on pulmonary opacities were determined. Findings: Patients responded to initiation of invasive high PEEP ventilation with markedly improved oxygenation, which was accompanied by reduced pulmonary opacities within 6h of mechanical ventilation. Decremental PEEP trials confirmed the need for high PEEP (17·9 ± 3·9 mbar) for optimal oxygenation in early COVID-19 ARDS, while driving pressures remained low. Prone positioning substantially increased oxygenation in COVID-19 ARDS. Interpretation: In early COVID-19 ARDS, substantial PEEP values were required for optimizing oxygenation. In our patient cohort, pulmonary opacities resolved during invasive mechanical ventilation with high PEEP suggesting recruitment of lung volume. Prone positioning improved oxygenation in early COVID-19 ARDS. Trial Registration: Currently registered in the German clinical trials register and the WHO International Clinical Trials Registry Platform, ID: DRKS00021688 Funding Statement: German Research Foundation (DFG), German Federal Ministry of Education and Research (BMBF). This study was supported by the Clinical Study Center of Berlin Institute of Health, Charite – Universitatsmedizin Berlin Declaration of Interests: All authors declare no conflict of interest. Ethics Approval Statement: The study was approved by the ethics committee of the Charite - Universitatsmedizin Berlin (EA2/066/20) and was performed according to the Declaration of Helsinki and Good Clinical Practice principles (ICH 1996). Written informed consent was obtained from all patients, or their legal representatives.