Immediate and long-term impact of medical emergency teams on cardiac arrest prevalence and mortality: a plea for periodic basic life-support training programs

Abstract

Objective: To evaluate whether the introduction of a program including a medical emergency team responding to widened criteria together with the institution-wide training on basic life support of all hospital staff would decrease cardiac arrest prevalence and mortality in patients at risk, in the immediate and long-term periods after the program.

Design: Before-after design.

Setting: Urban general hospital with 470 beds.

Patients: All patients admitted in the hospital between 2002 and 2006 were eligible. All patients with a medical emergency team activation were included. We compared cardiac arrest prevalence and mortality and in-hospital mortality before (2002), after (2003-2004), and long term after (2005-2006) the program implementation.

Measurements and main results: There was a significant (p = .037) decrease of 27% (95% confidence interval, 2%-46%) in cardiac arrest occurrence, 33% decrease (p = .014) in cardiac arrest mortality (95% confidence interval, 8%-52%), and a nonsignificant (p = .152) decrease of 17% (95% confidence interval, -7%-36%) in in-hospital mortality associated with the program implementation. No significant differences were found for any of the outcome variables between before and long term after periods. The main factor associated with in-hospital mortality was cardiac arrest. Factors affecting cardiac arrest were age, comorbidities, measures started before medical emergency team arrival and the intervention/program. The effect in the prevention of cardiac arrest has an adjusted relative risk, 0.646 (95% confidence interval, 0.450-0.876) and an absolute risk reduction of adjusted relative risk, 18% (95% confidence interval, 6%-29%). The program prevented one cardiac arrest for every five medical emergency team activations.

Conclusions: Widening criteria for hospital emergency calls together with an integrated training program may reduce cardiac arrest prevalence and mortality in at-risk patients. Program effectiveness was critically related to the staff education, awareness, and responsiveness to physiologic instability of the patients. Long-term effectiveness of the program may decrease in the absence of periodic and continued implementation of educational interventions.