Mortality of Mechanically Ventilated COVID-19 Patients in Traditional versus Expanded Intensive Care Units in New York

Abstract

Rationale: During the first wave of the coronavirus disease (COVID-19) pandemic in New York City, the number of mechanically ventilated COVID-19 patients rapidly surpassed the capacity of traditional intensive care units (ICUs), resulting in health systems utilizing other areas as expanded ICUs to provide critical care. Objectives: To evaluate the mortality of patients admitted to expanded ICUs compared with those admitted to traditional ICUs. Methods: Multicenter, retrospective, cohort study of mechanically ventilated patients with COVID-19 admitted to the ICUs at 11 Northwell Health hospitals in the greater New York City area between March 1, 2020 and April 30, 2020. Primary outcome was in-hospital mortality up to 28 days after intubation of COVID-19 patients. Results: Among 1,966 mechanically ventilated patients with COVID-19, 1,198 (61%) died within 28 days after intubation, 46 (2%) were transferred to other hospitals outside of the Northwell Health system, 722 (37%) survived in the hospital until 28 days or were discharged after recovery. The risk of mortality of mechanically ventilated patients admitted to expanded ICUs was not different from those admitted to traditional ICUs (hazard ratio [HR], 1.07; 95% confidence interval [CI], 0.95-1.20; P = 0.28), while hospital occupancy for critically ill patients itself was associated with increased risk of mortality (HR, 1.28; 95% CI, 1.12-1.45; P < 0.001). Conclusions: Although increased hospital occupancy for critically ill patients itself was associated with increased mortality, the risk of 28-day in-hospital mortality of mechanically ventilated patients with COVID-19 who were admitted to expanded ICUs was not different from those admitted to traditional ICUs.

Keywords: COVID pandemic; expanded ICU; hospital occupancy for critically ill patients; mechanically ventilated COVID-19 patients; traditional ICU.

Figure 1.

Change in the number of mechanically ventilated patients during the first wave of the COVID-19 pandemic in New York City. (A) Daily change in the number of intubated patients from March 1 to April 30. The maximum number was 84 on April 3. (B) Change in the number of mechanically ventilated patients in intensive care units (ICUs) from March 1 to April 30. The black line represents the number of patients in all ICUs, the blue line represents the number of patients in traditional ICUs, and the green line represents the number of patients in expanded ICUs. In the early phase of the pandemic, intubated COVID-19 patients were admitted primarily to traditional ICUs, but as traditional ICU capacity became saturated, the usage of expanded ICUs increased. COVID-19 = coronavirus disease 2019.

Figure 2.

Flow diagram of patients. COVID-19 = coronavirus disease 2019; DNR = do-not-resuscitate; ECMO = extracorporeal membrane oxygenation; ICU = intensive care unit; NH = Northwell Health system.

Figure 3.

Survival curves of the patients admitted to traditional and expanded intensive care units (ICUs). (A) Unadjusted Kaplan-Meier survival curves and (B) adjusted survival curves of mechanically ventilated COVID-19 patients in expanded ICUs compared with those in traditional ICUs. The P value was calculated using the (A) log-rank test and (B) proportional hazard regression analysis, respectively. COVID-19 = coronavirus disease 2019.