(RxWiki News) Epinephrine (adrenaline) is commonly used along with CPR in resurrecting patients who suffer cardiac arrest outside a hospital. However, it does not appear to be contributing to their survival.
Out-of-hospital cardiac arrest patients who receive both adrenaline and CPR are less likely to be alive one month later, and are not as likely to retain good brain functioning.
"Immediately call 9-1-1 when a loved one experiences cardiac arrest."
Akihito Hagihara, a lead researcher from Kyushu University Hospital in Japan, sought to assess the effectiveness of the drug before hospital arrival as previous findings have not been consistent. In addition to lower survival at 30 days, he found that patients that did survive were more likely to do so with neurological disability.
During the study researchers analyzed data from 417,188 patients who suffered out-of-hospital cardiac arrest in Japan between 2005 and 2008. The patients were over the age of 18, and all had been treated by emergency medical personnel before they were transported to the hospital.
They found that patients who received intravenous adrenaline before arriving at the hospital were less likely to survive the initial month after the cardiac arrest.
Investigators also discovered that only 1.4 percent of patients that received adrenaline had good neurological outcomes despite the 5.4 percent survival rate. This meant only 25 percent of patients receiving adrenaline were left with a with a good neurological outcome.
Researchers did note that all patients receiving adrenaline before they arrived at the hospital experienced a positive spontaneous return of circulation. Additional studies that include in-hospital data will be needed, researchers said.
In an accompanying editorial, Dr. Clifton W. Callaway, of the University of Pittsburgh, said he did expect there will ever be a larger observational study of the topic, though he noted such research cannot establish causal relationships in the way randomized trials can.
“Thus, properly evaluating this traditional therapy now seems necessary and timely and should consist of a rigorously conducted and adequately powered clinical trial comparing epinephrine with placebo during cardiac arrest," he said.
"Such a trial has previously seemed unethical, and investigators who have attempted to perform this comparison have received unwarranted criticism in their communities. While awaiting results of such a definitive trial, physicians and other practitioners involved in cardiac resuscitation must consider carefully whether continued use of epinephrine is justified.”
The study was published in the March 21 issue of the Journal of the American Medical Association.