Long term trends in medical emergency team activations and outcomes

. To analyze long-term medical emergency team (MET) operational trends including number of MET calls, trigger criteria for activation and clinical outcomes at a tertiary level, university hospital with a mature MET system.

The characteristics of 19,030 MET calls between 2000 and 2012 were analyzed in a single-centre, retrospective observational study. Rates indexed per 1000 hospital admissions for MET calls, cardiac arrests, unplanned admissions to the intensive care unit (ICU) and hospital mortality were used as performance measures of the MET. Descriptive statistics (mean±standard deviation) were applied and trends analyzed by one-way ANOVA with year 2000 set as the baseline using Dunn's correction for multiple comparisons, p<0.05.

Activations of the MET increased between 2000 and 2012 (19±3-30±4) and there were changes in reasons for activations over time. Clinical concern (worried) was the most common (22%) trigger criterion in 2000 followed by hypotension (21%) and decreased level of consciousness (17%). In 2012, hypotension was the most common trigger (32%), followed by decreased level of consciousness (19%) and clinical concern (15%). Rates of cardiorespiratory arrest (1.4±0.7-1.1±0.4) and unplanned ICU admission (5.0±1.2-5.9±1.0) did not change between 2000 and 2012. Hospital mortality decreased from 2005 onwards (15±3.4-12±2.2).

MET activity progressively increased during the study period and there was a change in pattern of specific triggering criteria. The sustained decrease in hospital mortality independent of cardiac arrest and unplanned ICU admissions rates suggests patient benefit from the MET system.