Unexpected ICU Transfer and Mortality in COVID-19 Related to Hospital Volume

INTRODUCTION: Coronavirus 2019 (COVID-19) illness continues to affect national and global hospital systems, with a particularly high burden to intensive care unit (ICU) beds and resources. It is critical to identify patients who initially do not require ICU resources but subsequently rapidly deteriorate. We investigated patient populations during COVID-19 at times of full or near-full (surge) and non-full (non-surge) hospital capacity to determine the effect on those who may need a higher level of care or deteriorate quickly, defined as requiring a transfer to ICU within 24 hours of admission to a non-ICU level of care, and to provide further knowledge on this high-risk group of patients. METHODS: This was a retrospective cohort study of a single health system comprising four emergency departments and three tertiary hospitals in New York, NY, across two different time periods (during surge and non-surge inpatient volume times during the COVID-19 pandemic). We queried the electronic health record for all patients admitted to a non-ICU setting with unexpected ICU transfer (UIT) within 24 hours of admission. We then made a comparison between adult patients with confirmed coronavirus 2019 and without during surge and non-surge time periods. RESULTS: During the surge period, there was a total of 86 UITs in a one-month period. Of those, 60 were COVID-19 positive patients who had a mortality rate of 63.3%, and 26 were COVID-19 negative with a 30.8 % mortality rate. During the non-surge period, there was a total of 112 UITs; of those, 24 were COVID-19 positive with a 37.5% mortality rate, and 90 were COVID-19 negative with a 11.1% mortality rate. CONCLUSION: During the surge, the mortality rate for both COVID-19 positive and COVID-19 negative patients experiencing an unexpected ICU transfer was significantly higher.