During a cardiac arrest, we know that early intervention by first responders and prompt transport to a hospital increase survival rates. Maintaining continuous cardiopulmonary resuscitation (CPR) also appears to be vital because interruptions could reduce the odds of survival. According to a study published recently in the American journal Circulation, a pause of as little as 20 seconds before defibrillation could have a negative impact on the patient’s chances of surviving.
In many cases of cardiac arrest, the heart continues to beat, but its rhythm is so erratic that the cardiac contractions are ineffective and the heart is no longer able to perform its work as a blood pump; this is called fibrillation. The latter can be corrected using an automated external defibrillator, a device that analyzes the victim’s heart rhythm before administering an electric shock if required. Defibrillation is associated with up to 30 percent better odds of survival if it is performed within the first few minutes.
However, there is an interruption in chest compressions just before defibrillation, for example, as patients are prepared for the application of a shock in order to “restart” their heart. The analysis published recently shows that the length of this phase of preparation has an impact on patients’ odds of survival. In cases where the pause lasted longer than 20 seconds, the odds of survival were cut by half compared to those where the pause lasted less than ten seconds. Each additional five seconds of delay before defibrillation reduced the patient’s chance of survival by 14 to 18 percent.
Over 40,000 Canadians die of cardiac arrest each year. Quick intervention on the part of loved ones or even strangers can have an impact on the patient’s prognosis, which is why it is so important that everyone master basic first-aid and resuscitation techniques.
If one day you find yourself having to perform CPR, remember the importance of avoiding pauses in the chest compressions until help arrives.