Survival Chances For Cardiac Arrest During CPR

Only around 25% of patients survive to hospital discharge after being admitted to the emergency department for cardiac arrest. This common catastrophic medical emergency with a high mortality rate is an important public health issue, affecting around 300,000 adults every year in America alone. Unfortunately, studies have shown that long resuscitation times are linked to lower odds of survival, but there are no specific recommendations on when to stop resuscitation. 

This study was designed to measure the effects of CPR duration, using the largest cardiac dataset in the world, utilizing data from 348,996 adults with an average age of 67 years old who experienced an in-hospital cardiac arrest.  CPR was defined as the interval between the start of compression and the first return of spontaneous circulation (ROSC) or the termination of resuscitation. The main measures of interest were survival to discharge and favorable function at discharge, defined as a brain performance score of 1 representing good cerebral performance, and 2 representing moderate cerebral disability on a 5-point scale. 

Findings show that 67% of the patients achieved ROSC with an average CPR duration of 7 minutes, and 33% did not achieve ROSC with an average CPR duration of 20 minutes after accounting for a range of potentially influential factors and pre-existing conditions. 

The findings revealed that at one minute of CPR, the probabilities of survival and a favorable functional outcome among the patients were 22% and 15% respectively. But as the duration increased the probabilities of survival and favorable functional outcome decreased to less than 1% when the duration reached 39 minutes and less than 1% for favorable functional outcome when CPR duration reached 32 minutes. 

This is an observational study, meaning that the findings should be interpreted with care. The study was also not without its limitations such as relying on the assumption that any termination of resuscitation was appropriate. It was noted that collecting time variables during CPR was difficult and they were not able to account for the severity of underlying conditions and the quality of CPR or post resuscitation care the patients received at each hospital. 

 “The findings provide resuscitation teams, patients, and their surrogates with insights into the likelihood of favorable outcomes if patients pending the first return of spontaneous circulation continue to receive further cardiopulmonary resuscitation,” the researcher concluded.