Frequency of and associations with alterations of medical emergency team calling criteria in a teaching hospital emergency department.

Background: Medical emergency team (METs), activated by vital sign-based calling criteria respond to deteriorating patients in the hospital setting. Calling criteria may be altered where clinicians feel this is appropriate. Altered calling criteria (ACC) has not previously been evaluated in the emergency department (ED) setting.

Objectives: The objectives of this study were to (i) describe the frequency of ACC in a teaching hospital ED and the number and type of vital signs that were modified and (ii) associations between ACC in the ED and differences in the baseline patient characteristics and adverse outcomes including subsequent MET activations, unplanned intensive care unit (ICU) admissions and death within 72 h of admission.

Methods: Retrospective observational study of patients presenting to an academic, tertiary hospital ED in Melbourne, Australia between January 1st, 2019 and December 31st, 2019. The primary outcome was frequency and nature of ACC in the ED. Secondary outcomes included differences in baseline patient characteristics, frequency of MET activation, unplanned ICU admission, and mortality in the first 72 h of admission between those with and without ACC in the ED.

Results: Amongst 14 159 ED admissions, 725 (5.1%) had ACC, most frequently for increased heart or respiratory rate. ACC was associated with older age and increased comorbidity. Such patients had a higher adjusted risk of MET activation (odds ratio [OR]: 3.14, 95% confidence interval [CI]: 2.50-3.91, p = <0.001), unplanned ICU admission (OR: 1.97, 95% CI: 1.17-3.14, p = 0.016), and death (OR: 3.87, 95% CI: 2.08-6.70, p = 0.020) within 72 h.

Conclusions: ACC occurs commonly in the ED, most frequently for elevated heart and respiratory rates and is associated with worse patient outcomes. In some cases, ACC requires consultant involvement, more frequent vital sign monitoring, expeditious inpatient team review, or ICU referral.