Capnodynamic monitoring of lung volume and blood flow in response to increased positive end-expiratory pressure in moderate to severe COVID-19 pneumonia: an observational study

Background The optimal level of positive end-expiratory pressure (PEEP) during mechanical ventilation for COVID-19 pneumonia remains debated and should ideally be guided by responses in both lung volume and perfusion. Capnodynamic monitoring allows both end-expiratory lung volume ( EELV_CO_2 ) and effective pulmonary blood flow (EPBF) to be determined at the bedside with ongoing ventilation. Methods Patients with COVID-19-related moderate to severe respiratory failure underwent capnodynamic monitoring of EELV_CO_2 and EPBF during a step increase in PEEP by 50