Beyond the intensive care unit: a review of interventions aimed at anticipating and preventing in-hospital cardiopulmonary arrest.

Despite more than four decades of experience with in-hospital cardiopulmonary arrest, outcomes have remained poor. Numerous studies have documented the physiological instability leading to clinical deterioration, which often precedes cardiopulmonary arrest. These physiological changes often go unrecognized or are acted upon inadequately. This has led to the development of interventions aimed at anticipating and/or preventing cardiopulmonary arrest. In this review, we summarize the current literature regarding outcomes from in-hospital cardiopulmonary arrest, the physiological instability leading to clinical deterioration which often precedes cardiopulmonary arrest, and the various interventions to anticipate and prevent in-hospital cardiopulmonary arrest. These interventions include the use of intermediate care units, Modified Early Warning Scores (MEWS) and Medical Emergency Teams (MET). These interventions may have the potential to decrease the cardiac arrest rate and in-hospital mortality rate associated with cardiac arrest; however, controversy remains regarding some of these interventions. The use of intermediate care units may require an organized approach to identify patients who are acutely ill and would benefit from this specialized care. There is not enough evidence currently to support the benefit of Modified Early Warning Scores to prevent in-hospital cardiopulmonary arrest. Recent studies of the Medical Emergency Team have shown a significant decrease in cardiac arrest and overall mortality rates with this intervention. The Medical Emergency Team is an intervention, which requires further studies to define its role in other aspects of hospital patient care.