COVID-19 Ventilator Management Strategies: What We Have Learned and Future Management Options?

RATIONAL: Coronaviruses are RNA viruses that primarily affect the respiratory system. Patients with Coronavirus Disease-19 (COVID-19) pneumonia and respiratory distress often require hospitalization, ICU admission, intubation and/or non-invasive ventilation, and circulatory support. Some experts suggest that the pathophysiology of traditional ARDS and that of the lung disease associated with COVID-19 are different. It is proposed that the severe hypoxemia in COVID-19 patients is the result of hypoxia-induced vasoconstriction and a large burden of microthrombi which result in intrapulmonary shunting. Therefore, COVID-related ARDS-like patterns of disease may not respond to World Health Organization (WHO) recommendations for early intubation and ARDS Network (ARDSNet) recommendations for FiO2-titrated Positive End-Expiratory Pressure (PEEP) administration and ventilator support. Given the distinct pathophysiology of COVID-19-related ARDS, higher PEEP may indicate mechanical over-inflation of the alveoli resulting in volume trauma in addition to compromising preload and decreasing cardiac output, worsening the pulmonary hypoperfusion. The aim of this study was to examine the rate of death associated with initial and subsequent (48-hour) PEEP settings of 10cmH2O and higher in COVID-19 patients. We hypothesized that higher PEEP settings may lead to increased mortality. METHODS: We conducted a retrospective chart review of patients who presented or were transferred to our facility with COVID-19 and were subsequently intubated from March 1st until April 30th, 2020. Charts were reviewed for initial and 48-hour PEEP settings. Mortality, SARS CoV2 results, clinical data and demographics were also recorded. RESULTS: A total of 74 patients were included in the review. Of these, 53 patients had initial PEEP setting of >10cmH2O and 46 patients had PEEP settings >10cmH2O 48 hours after intubation. Thirty-seven patients had PEEP settings >10cmH2O both initially and 48 hours later. Thirty-seven patients who had an initial PEEP setting of >10 cmH220 died, (70%). Forty patients who had PEEP settings >10cmH2O at 48hrs died (87%). Twenty-seven patients who had both a PEEP setting >10 cmH2O initially and at 48 hours died (73%). CONCLUSIONS: There appears to be an association in COVID-19 patients between high mortality rates and high PEEP settings. The marked association is strong enough, in our view, to suggest that conventional ventilator settings recommended by ARDSNet may not apply to patients experiencing COVID-19-associated ARDS and in fact, may be leading to worse patient outcomes.