Prehospital hypoxemia, measured by pulse oximetry, predicts hospital outcomes during the New York City COVID-19 pandemic

Elizabeth A Lancet; Dario Gonzalez; Nikolaos A Alexandrou; Benjamin Zabar; Pamela H Lai; Charles B Hall; James Braun; Rachel Zeig-Owens; Douglas Isaacs; David Ben-Eli; Nathan Reisman; Bradley Kaufman; Glenn Asaeda; Michael D Weiden; Anna Nolan; Hugo Teo; Eric Wei; Shaw Natsui; Christopher Philippou; David J Prezant

doi:10.1002/emp2.12407

Prehospital hypoxemia, measured by pulse oximetry, predicts hospital outcomes during the New York City COVID-19 pandemic

J Am Coll Emerg Physicians Open. 2021 Mar 17;2(2):e12407. doi: 10.1002/emp2.12407. eCollection 2021 Apr.

Authors

Elizabeth A Lancet^{1

2}, Dario Gonzalez¹, Nikolaos A Alexandrou¹, Benjamin Zabar¹, Pamela H Lai¹, Charles B Hall², James Braun¹, Rachel Zeig-Owens^{2

3}, Douglas Isaacs¹, David Ben-Eli¹, Nathan Reisman¹, Bradley Kaufman¹, Glenn Asaeda¹, Michael D Weiden^{3

4}, Anna Nolan^{3

5}, Hugo Teo⁶, Eric Wei⁶, Shaw Natsui⁶, Christopher Philippou⁶, David J Prezant^{1

2

3

5}

Affiliations

¹ Office of Medical Affairs Fire Department of the City of New York Brooklyn New York USA.
² Department of Epidemiology and Population Health Albert Einstein College of Medicine Bronx New York USA.
³ Bureau of Health Services Fire Department of the City of New York Brooklyn New York USA.
⁴ Pulmonary, Critical Care, and Sleep Medicine Division, Department of Medicine NYU School of Medicine New York New York USA.
⁵ Pulmonary Medicine Division, Department of Medicine Montefiore Medical Center and Albert Einstein College of Medicine Bronx New York USA.
⁶ New York City Health + Hospitals New York New York USA.

Abstract

Objective: To determine if oxygen saturation (out-of-hospital SpO2), measured by New York City (NYC) 9-1-1 Emergency Medical Services (EMS), was an independent predictor of coronavirus disease 2019 (COVID-19) in-hospital mortality and length of stay, after controlling for the competing risk of death. If so, out-of-hospital SpO2 could be useful for initial triage.

Methods: A population-based longitudinal study of adult patients transported by EMS to emergency departments (ED) between March 5 and April 30, 2020 (the NYC COVID-19 peak period). Inclusion required EMS prehospital SpO2 measurement while breathing room air, transport to emergency department, and a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction test. Multivariable logistic regression modeled mortality as a function of prehospital SpO2, controlling for covariates (age, sex, race/ethnicity, and comorbidities). A competing risk model also was performed to estimate the absolute risks of out-of-hospital SpO2 on the cumulative incidence of being discharged from the hospital alive.

Results: In 1673 patients, out-of-hospital SpO2 and age were independent predictors of in-hospital mortality and length of stay, after controlling for the competing risk of death. Among patients ≥66 years old, the probability of death was 26% with an out-of-hospital SpO2 >90% versus 54% with an out-of-hospital SpO2 ≤90%. Among patients <66 years old, the probability of death was 11.5% with an out-of-hospital SpO2 >90% versus 31% with an out-of-hospital SpO2 ≤ 90%. An out-of-hospital SpO2 level ≤90% was associated with over 50% decreased likelihood of being discharged alive, regardless of age.

Conclusions: Out-of-hospital SpO2 and age predicted in-hospital mortality and length of stay: An out-of-hospital SpO2 ≤90% strongly supports a triage decision for immediate hospital admission. For out-of-hospital SpO2 >90%, the decision to admit depends on multiple factors, including age, resource availability (outpatient vs inpatient), and the potential impact of new treatments.

Abstract

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