Comparison of mortality in emergency department patients with immediate versus delayed hypotension

Abstract

BackgroundHypotension in the emergency department (ED) is known to be associated with increased mortality, however, the relationship between timing of hypotension and mortality has not been investigated. The objective of the study was to compare the mortality rate of patients presenting with hypotension with those who develop hypotension while in the ED. MethodsThis was a retrospective cohort study in a large academic medical center collected from January 2018–December 2021. Patients were included if they were ≥ 18 years old and had at least one recorded systolic blood pressure (SBP) ≤ 90 in the ED. Patients were separated into medical and trauma presentations by chief compliant. The primary outcome was in-hospital mortality, which included any deaths between ED arrival and hospital discharge. Further analysis examined the association of time to the first hypotensive SBP measurement with mortality. ResultsThere were 212,085 adult patients who presented to the ED during the study period, with 4053 (1.9%) patients having at least one hypotensive blood pressure measurement. The mortality rate was 0.8% for all patients and 10.0% for patients with hypotension. There were 676 unique chief complaints, of which 86 (12.7%) were determined to be trauma related. This grouping resulted in 176,947(83.4%) patients classified as medical and 35,138(16.6%) patients as trauma. For patients presenting with medical complaints, there was not a significant difference in mortality for patients who were hypotensive on arrival and those who developed hypotension during their ED stay (RR 1.19 [95% CI:0.97–1.39]). Similarly, there was no difference for patients with trauma (RR 0.6 [95% CI: 0.31–1.24]). However, for all patients, there was a significant trend toward decreased mortality for every hour after arrival until the development of hypotension, and increased mortality with increasing number of hypotensive measurements recorded. ConclusionThis study demonstrated hypotension in the ED was associated with a very significantly increased risk of in-hospital mortality. However, there was no significant increase in mortality between those patients with hypotension on arrival those who develop hypotension while in the ED. These finding underscore the importance of careful hemodynamic monitoring for patients in the ED throughout their stay.