Clinical course and outcomes of critically ill COVID-19 patients in two successive pandemic waves

Rationale The progress of COVID-19 from moderate to severe may be precipitous, while the heterogenous characteristics of the disease pose challenges to the management of these patients. Objectives To characterize the clinical course and outcomes of critically ill patients with COVID-19 during two successive waves. Methods We leveraged the multi-center SuPAR in Adult Patients With COVID-19 (SPARCOL) study and collected data from consecutive patients requiring admission to the intensive care unit from April 1 st to December 31 st , 2020. Measurements and Main Results Of 252 patients, 81 (32%) required intubation and mechanical ventilation. Of them, 17 (20.9%) were intubated during the first wave, while 64 (79%) during the second wave. The most prominent difference between the two waves was the overall survival (first wave 58.9% vs. second wave 15.6%, adjusted p-value=0.006). This difference is reflected in the prolonged hospitalization during the first wave. The mean ICU length of stay (19.1 vs. 11.7 days, p=0.022), hospital length of stay (28.5 vs. 17.1 days, p=0.012), and days on ventilator (16.7 vs. 11.5, p=0.13) were higher during the first wave. A significant difference between the two waves was the development of bradycardia. In the first wave, 2 (11.7%) patients developed sinus bradycardia only after admission to the intensive care unit, while in the second wave, 63 (98.4%) patients developed sinus bradycardia during hospitalization. Conclusions Survival of critically ill patients with COVID-19 was significantly lower during the second wave. The majority of these patients developed sinus bradycardia during hospitalization.