Systematically lengthening the duration of resuscitation efforts for patients who have in-hospital cardiac arrests could improve survival with no adverse impact on neurological status, according to a report published Sept. 4 in The Lancet.
In a study of 64,339 patients who had in-hospital cardiac arrests at 435 U.S. hospitals over an 8-year period, this survival benefit was independent of numerous patient factors, wrote Dr. Zachary D. Goldberger of the division of cardiovascular medicine, University of Michigan, Ann Arbor, and his associates.
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Longer resuscitation attempts may lead to increased survival in hospital patients suffering from cardiac arrest.
Importantly, they wrote, neurologic status was not affected by the duration of resuscitation efforts, so patients revived after relatively long CPR attempts of 30 minutes or more were as neurologically intact as were those revived after brief attempts of less than 15 minutes.
"Our most notable result was that long resuscitation attempts might be linked to increased rates of return of spontaneous circulation and survival to discharge," they said.
At present, resuscitation guidelines do not address the issue of when to terminate such efforts, and there are not enough data available to guide practice. "Clinicians are frequently reluctant to continue efforts when return of spontaneous circulation does not occur shortly after initiation of resuscitation, in view of the overall poor prognosis for such patients," the researchers noted.
They examined the issue using information from the Get With The Guidelines-Resuscitation database, the largest registry of in-hospital cardiac arrests in the world. A total of 31,198 patients (48.5%) achieved return of spontaneous circulation, while 33,141 (51.5%) died after termination of resuscitation efforts.
Approximately 80% of patients who survived to hospital discharge had favorable neurologic status. The rate of favorable status did not differ significantly by duration of resuscitation: It was 81.2% for patients in whom resuscitation attempts lasted less than 15 minutes, 80.0% for those in whom resuscitation attempts lasted 15-30 minutes, and 78.4% for those in whom resuscitation attempts lasted longer than 30 minutes.
As expected when there is no consensus on the appropriate duration of resuscitation attempts, the investigators found wide variation among hospitals in this practice.
Overall, the median duration of resuscitation efforts was 17 minutes. When the hospitals were divided into quartiles based on this duration, those in the quartile with the shortest interval had a median duration of 16 minutes, while those in the quartile with the longest interval had a median duration of 25 minutes.
Resuscitation efforts lasted more than 50% longer at hospitals in the longest quartile compared with those in the shortest quartile.
Patients at the hospitals with longer durations of resuscitation efforts had significantly higher overall survival and significantly higher survival to hospital discharge than did those at hospitals with shorter durations of resuscitation efforts, Dr. Goldberger and his colleagues said (Lancet 2012 Sept. 4 [doi:10.1016/S0140-6736(12)60862-9]).
The study findings suggest that standardizing resuscitation procedures and identifying a minimum duration could improve patient survival. "Prolongation of resuscitation attempts by 10 or 15 minutes might have only a slight effect on resources once efforts have already begun, but could improve outcomes," the investigators noted.
"We are unable to provide a specific cutoff from these data and are hesitant to speculate," especially because this was an observational study that cannot establish cause and effect. Moreover, several variables that almost certainly affected the duration of resuscitation efforts were not addressed in this study, such as the quality of chest compressions and the availability at each hospital of percutaneous intervention.
It is even possible that the duration of resuscitation attempts is merely a marker for "more comprehensive care" with longer CPR performed at centers where resuscitation guidelines are reliably implemented, they added.
It should also be noted that this study did not address long-term outcomes in survivors of resuscitation. "The extent to which critically ill patients benefit from survival months to years after cardiac arrest should be the ultimate measure of the usefulness of resuscitation measures," Dr. Goldberger and his associates said.
The study was funded by the American Heart Association, the Robert Wood Johnson Foundation, and the National Heart, Lung, and Blood Institute. Dr. Goldberger reported no financial conflicts of interest, and one of his associates reported ties to Medtronic and United Health Care.