No Long-Term Benefit of Adrenaline in Cardiac Arrest
Administering adrenaline to patients after they suffer cardiac arrest outside of a hospital does not increase their chances of long-term survival, according to a new study.
Recommended practices dictate that most patients who suffer cardiac arrest receive adrenaline, yet, even with the drug, long-term survival rates are low - as many as 90% of people who experience cardiac arrest outside of a hospital die, even with adrenaline.
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In order to further explore the efficacy of adrenaline in these patients, researchers at St. Michael’s Hospital in Toronto, Canada, looked at data from 14 randomized, controlled trials evaluating adrenaline vs placebo and vasopressin in adults with cardiac arrest.
Standard dose adrenaline (SDA) showed improved return of spontaneous circulation (ROSC) (RR 2.80, 95%CI 1.78–4.41, p < 0.001) and survival to admission (RR 1.95, 95%CI 1.34–2.84, p < 0.001) compared to placebo. SDA showed decreased ROSC (RR 0.85, 95%CI 0.75–0.97, p = 0.02; I2 = 48%) and survival to admission (RR 0.87, 95%CI 0.76–1.00, p = 0.049; I2 = 34%) compared to high dose andrenaline.
However, there was no benefit seen with adrenaline to either neurological outcomes or survival to discharge.
"It is thought that the short-term benefit of adrenaline in improving coronary blood flow may occur at the expense of other organs," researchers wrote in an accompanying press release. "The drug can cause small blood vessels in other organs to contract, such as in the gut, liver, and kidneys, thus limiting the blood flow to these organs."
The recommended that rather than administer adrenaline, paramedics instead focus on the use of CPR and defibrillators in patients with cardiac arrest.
"The use of adrenaline has been the standard of care for so long that it's been hard to change the culture," said Dr. Lin. "We have reached a point in time where physicians and paramedics have to change the way we think."
–Michael Potts
Adrenaline does little to increase patient's survival after cardiac arrest [press release]. St. Michael’s Hospital. Toronto, Canada. April 17, 2014.
Adrenaline for out-of-hospital cardiac arrest resuscitation: A systematic review and meta-analysis of randomized controlled trials [published online ahead of print March 15, 2014. Resuscitation. DOI: http://dx.doi.org/10.1016/j.resuscitation.2014.03.008