Pronation response as a predictor of COVID-19-related acute respiratory distress syndrome mortality

ABSTRACT

INTRODUCTION: Severe acute respiratory failure is a common complication of COVID-19, with refractory hypoxemia being a hallmark finding in severe illness and a common cause of mortality. With limited therapeutic strategies, management centers on good supportive care. Prone positioning has been shown to improve oxygenation and survival in patients with moderate-to-severe acute respiratory distress syndrome (ARDS) but the impact of prone positioning in COVID-19 with severe hypoxemia is unknown. This study aims to examine the response to proning as a predictor of COVID-19 related mortality. METHODS: This is a single-center, retrospective analysis of critically ill patients with COVID-19 confirmed by PCR. Patients were included if they were invasively ventilated, and if supportive care included prone positioning for management of refractory hypoxemia. Data points collected include demographics, ventilator settings, rates of mortality and progression to ECMO, ventilator-days, and time between symptom onset and intubation, hospital and ICU admission. Endpoints included response in oxygenation (PaO2FiO2) and mortality. RESULTS: Forty-nine patients were included in the analysis. The average age was 56.9, and 61% of the patients were male. Patients had an average of 19 ventilator-days (2-52), 21 ICU-days (4-54), 26 hospital-days (8-65), an ECMO rate of 27%, and a mortality rate of 55%. Of the 22 survivors, there was an average increase in PaO2FiO2 by 108, 93.1, and 93 for each of the first three pronations respectively. For the 27 nonsurvivors, there was an average increase in PaO2FiO2 by 76.1, 84.3, and 50.9 for the first three pronations. The difference in improvement in PaO2FiO2 was not statistically significant between survivors and non-survivors. There was no inflection point that could be determined that provided a high sensitivity and specificity to predict mortality or need for ECMO based on response to pronation at any of the time points. CONCLUSIONS: Proning improves PaO2FiO2 in patients with severe hypoxemia related to COVID-19. Survivors in our study had a numerically greater response to proning, but this finding was not statistically significant. The clinical significance remains unclear. Larger studies assessing the efficacy of proning in critically ill patients with COVID-19 are needed.