Tuesday, June 30, 2015

Yet another study on rapid response systems

The evidence in support of RRS is mixed. The RRS is favored in some before and after studies but not RCTs. This study, published in Resuscitation, is another before and after study but it does have some strengths compared to the older ones. From the paper:


For the period 2002–2009, we compared a teaching hospital with a mature RRS, with three similar teaching hospitals without a RRS. Two non-RRS hospitals began implementing the system in 2009 and a third in January 2010. We compared the rates of in-hospital cardiopulmonary arrest (IHCA), IHCA-related mortality, overall hospital mortality and 1-year post discharge mortality after IHCA between the RRS hospital and the non-RRS hospitals based on three separate analyses: (1) pooled analysis during 2002–2008; (2) before–after difference between 2008 and 2009; (3) after implementation in 2009.


During the 2002–2008 period, the mature RRS hospital had a greater than 50% lower IHCA rate, a 40% lower IHCA-related mortality, and 6% lower overall hospital mortality. Compared to 2008, in their first year of RRS (2009) two hospitals achieved a 22% reduction in IHCA rate, a 22% reduction in IHCA-related mortality and an 11% reduction in overall hospital mortality. During the same time, the mature RRS hospital showed no significant change in those outcomes but, in 2009, it still achieved a crude 20% lower IHCA rate, and a 14% lower overall hospital mortality rate. There was no significant difference in 1-year post-discharge mortality for survivors of IHCA over the study period.

A related editorial makes some important points. First, the rationale and plausibility for the RRS are strong. In hospital arrests are often preceded by hours or even days of deterioration, presenting opportunities for intervention. Why can't the RRS be proven in high level studies? For one thing, says the editorial writer, the RRS is not a “clean intervention.” How it's used depends on the staffing and culture of the institution. It is one thing to say your hospital has a rapid response system but quite another to use it for all it's worth. What's most important is to recognize the signs of deterioration, then “have the big discussion” or pull out all the stops early. That, of course, is nothing more than a principle of clinical vigilance we've known for decades: when you smell a rat, get aggressive early.

Bottom line? A rapid response system can be beneficial in many ways depending on the needs and resources of the institution. However, general claims that these systems save lives cannot be justified.

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