Giving patient's adrenaline after they suffered a cardiac arrest is not very effective, according to a recent study Counsel and Heal reported.

Researchers from St. Michael's Hospital in New Jersey found that administering adrenaline to patients after they suffered from a cardiac arrest outside of a hospital does not increase their prospects of surviving long-term.

Cardiac arrest occurs when a person's heart stops beating. Unless the heart is restarted within minutes, the person usually dies. More than 90 percent of people who experience a cardiac arrest outside of a hospital will die before reaching a hospital or soon after. Adrenaline is often given to hospital patients who suffer from a cardiac arrest. It is a treatment option that has been traditionally used on inpatients.

"The vast number of patients who have a cardiac arrest get adrenaline, which has been the drug recommended in treating cardiac arrest for decades," Dr. Steve Lin, an emergency physician and trauma team leader at St. Michael's, said in a statement. "Yet, despite advances in medical treatment, long-term survival rates of patients who suffer a cardiac outside a hospital and receive adrenaline remains low."

For the study, researchers looked at clinical trials and data involving out-of-hospital cardiac arrests that were published in medical journals up to July 2013 and found that adrenaline showed no benefit in survival to discharge from hospital or neurological outcomes.

Lin and his colleagues found that the short-term benefit of adrenaline in improving coronary blood flow may occur at the expense of other organs. 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.

While adrenaline is also given to patients who suffer cardiac arrest in hospitals, Dr. Lin looked only at studies of those outside of a hospital because the cause of cardiac arrest tends to be different between the two settings. Those outside a hospital tend to be related to heart disease and heart attacks.

 Cardiac arrests in the hospital are usually related to the reasons why a patient would be in the hospital, such as infections or respiratory diseases.

The findings were recently published in the journal Resuscitation.