Home Critical Care A new reality check for rapid response teams

A new reality check for rapid response teams

March 2009

Published in the March 2009 issue of Today’s Hospitalist

LOUDLY CHAMPIONED BY ORGANIZATIONS like the Institute for Healthcare Improvement, rapid response teams (RRTs) are a battle-tested, proven way to save lives, right? Not so fast, according to a new study that looked at how RRTs affect hospital-wide mortality.

While RRTs have been embraced by the quality improvement community, some say that past studies on the teams’ effectiveness focused too much on reducing the number of codes and not enough on other outcomes like mortality. In addition, critics say, past studies often didn’t include patients who were transferred to the ICU after an RRT was called or account for seasonal variations in illness severity.

To address those concerns, a research team led by Paul S. Chan, MD, MSc, looked at the effect a rapid response team had in a large tertiary care hospital in Kansas City, Mo. But instead of merely looking at the total number of codes before and after an RRT was implemented, the study examined other factors, like the severity of illness by season and patient mortality rates.

The results? The study, which was published in the Dec. 3, 2008, Journal of the American Medical Association (JAMA), found that RRTs produced no statistically significant differences in either the incidence of codes or mortality.

“I am not sure what the next steps for existing RRTs should be,” says Dr. Chan, a cardiologist at St. Luke’s Mid- America Heart Institute in Kansas City. “This study raises questions about whether or not RRTs are as effective as they are promoted to be.”

Dr. Chan spoke to Today’s Hospitalist about those findings.

Why did your study come up with different conclusions than previous research?

Our study is one of the largest of RRTs in the literature, and it’s the only adult study that controls for trends that occur before the implementation of the RRT. Almost all previous studies measured code rates as the primary end point instead of mortality.

And prior studies had significant methodologic limitations. For instance, the control period in some studies was during winter months when patients are sicker, and the intervention period was during summer months when patients are less sick. This could be one reason that previous studies found that RRTs lowered mortality.

What’s really happening then with RRT patients?

If you decrease code rates outside the ICU but increase them in the ICU after a patient has had an RRT intervention and has been transferred there, you may be doing little more than rearranging chairs on the deck.

After an RRT, many patients may be transferred to the ICU where they may go on to code or have a do-not-resuscitate [DNR] order put into place. Not counting these patients as part of your end point “because only codes outside the ICU are measured “gives the impression, however illusory, that we’re making a difference when we’re really not improving survival.

Would calling more RRTs lead to better mortality results?

No, we measured undertreatment and underuse and found they didn’t substantially affect our mortality findings.

The emotional appeal of RRTs is that if we catch patients before they code, we can prevent patient deaths. That assumes we can reverse what’s going on physiologically.

But we have yet to establish whether RRTs can reverse physiological deterioration even if they are called early enough. It may be that the RRT is an intervention that has no long-term effect. Even if you prevent a cardiopulmonary arrest short-term, patients may not survive to discharge.

Did you find no benefits for adults from RRTs at all?

The interdisciplinary work across respiratory therapists, nurses and doctors probably improves satisfaction levels among medical staff. And studies have shown a high degree of satisfaction among nurses who have RRT participation.

There’s a lot of enthusiasm for RRTs because they get people talking about things that need to be solved, so they generate energy and momentum. But the idea that RRT interventions improve survival has not been consistently and reproducibly shown.

Don’t they have an effect on the use of DNRs?

We found that rates of establishing a DNR were higher after an RRT was called on a particular patient. However, you cannot exclude those patients from the analyses of mortality as that would bias results in favor of the RRT. No doubt we should engage in end-of-life discussions when appropriate, but sustaining an RRT may not be the best medium to improve these discussions with patients.

Another JAMA study in 2007 found that RRTs did improve mortality in a pediatric setting.

There may be a difference in RRT effectiveness in a pediatric setting. I’m a trained pediatrician, so I recognize the differences. For example, respiratory arrest may be more easily reversed in children. Kids have fewer comorbidities and may code from different etiologies, and fewer are made DNR. Then again, there are about four pediatric RRT studies, and that was the only one to show a difference in mortality.

Is there any harm in using RRTs?

RRTs are not causing direct harm, but they may take away from other established quality improvement programs that have known effectiveness. If hospitals are not, for instance, adequately funding disease management for heart failure, that would be a concern for me because the efficacy of these programs has been established.

Is your study enough to slow the RRT momentum?

Our study has its own limitations. It is not a randomized trial but an observational study using a before vs. after design.

To adequately assess RRT effectiveness, we would need large-scale studies in which mortality outcomes have been adequately powered. If you want to detect a 5% mortality difference with 80% statistical power, you would need six times the number of hospital admissions that we had. That’s about 150,000 admissions before and 150,000 admissions after an RRT implementation.

Until such trials are performed, there remains no consistent evidence that RRTs indeed save lives. Hospitals should weigh decisions about how best to distribute their limited quality-improvement personnel and financial resources accordingly.

Paula S. Katz is a freelance health care writer based in Vernon Hills, Ill.