It is better to go for Defibrillation rather than Continuing with CPR beyond One Minute
A recent study conducted by Ottawa Hospital Research Institute (OHRI), the University of Ottawa and the Resuscitation Outcomes Consortium (ROC) has shown that extending the period of initial cardiopulmonary resuscitation (CPR) by paramedics and other emergency personnel from one to three minutes does not seem to add any benefit to the patient. Published in the New England Journal of Medicine, it is the largest randomized cardiac arrest trial in the world. The study has helped to resolves a worldwide controversy about how cardiac arrest should be dealt with in those first crucial minutes after a patient collapses, as per Dr. Ian Stiell, head of emergency medicine at Ottawa Hospital, and the Principal investigator of the study.
Of more than 350,000 people who suffer from a sudden cardiac arrest in the U.S and Canada, less than 10% survive. In a cardiac arrest, the heart suddenly stops pumping blood, and the patient collapses with no pulse. Some times, a patient suffering from a heart attack can also go into cardiac arrest. Immediate CPR can be life saving in this condition. It increases the blood flow to the brain for a short time and can help in keeping you alive. However, in one third of the patients of cardiac arrest, the heart requires to be given a shock with the help of a defibrillator for it to start pumping blood again. The other two thirds require emergency medication.
A few earlier studies had suggested continuing with the CPR for three minutes before resorting to defibrillation. But the current study has shown that prolonging the period of CPR offers no advantage to a patient in cardiac arrest. According to Stiell, as the heart stops pumping blood to the brain, the oxygen supply is snapped. By the end of three to four minutes, the oxygen deprived heart is already in a bad shape and the response to defibrillation would not be on the expected lines. CPR keeps the oxygen supply to the heart going, but the response with earlier defibrillation is better. However, CPR should be continued along with defibrillation till the time the normal rhythm of the heart is restored, unless the patient has already succumbed to the cardiac arrest.