Using markedly abnormal vital signs in the emergency department to anticipate needs for intensive care unit admission

Objective: To assess the utility and relative strength of markedly abnormal vital signs thresholds (triggers) in prediction of the needs for intensive care unit (ICU) admission from the emergency department (ED). Methods: A retrospective cohort study performed in a 37 000 annual visit, urban, community teaching ED. All adult patient encounters from July 10, 2011 to July 9, 2013 were eligible for inclusion. The primary outcome was ICU admission from the ED. We collected the incidence of trigger vital signs (heart rate>130 bpm, heart rate<40 bpm, respiratory rate>30 breaths per minute, respiratory rate< breaths 8 per minute, oxygen saturation<90%, systolic blood pressure<90 mmHg) as binary variables for each patient enrolled. Univariate and multi-variable logistic regression models were created to determine the ability of the trigger vital signs to predict ICU admission. Results: Total of 68 554 patient encounters were included in the analysis. Of these, 2 355 [3.4%, 95% confidence intervals (CI) 3.3%-3.6%] patients exhibited trigger vital signs, and 1 135 (1.7%, 95% CI 1.6%-1.8%) patients were admitted to ICU. All trigger vital signs were strongly associated with admission to the ICU and demonstrated higher odds of ICU admission with HR<40 (odds ratio 5.2, with 95% CI 2.7-10.1) being the best predictor among the studied covariates. The likelihood of ICU admission increased in a linear fashion with the number of trigger vital signs exhibited. Conclusions: Trigger vital signs serve as predictors that an ED patient may need admission to the ICU and may serve as a tool to expedite disposition of these resource-intensive patients