A study of more than 17,238 out-of-hospital cardiac arrest patients found that nearly all survivals were achieved within 35 minutes of performing cardiopulmonary respiration and that there was little benefit beyond that time.
"The decision regarding when to stop resuscitation efforts is one of the biggest challenges for emergency medical services personnel or clinicians," Yoshikazu Goto, MD, author of the study and director of the department of emergency and critical care medicine at Kanazawa University Hospital in Japan, said in a statement. "However, the appropriate duration of CPR is not clear. Clinicians have raised concerns that lengthy resuscitation efforts might be futile. We investigated how long CPR should be conducted to achieve maximum survival and favorable neurological outcome."
Results showed that the probability of patient survival declined with each minute of CPR, and that 99.2 percent of survivors with favorable neurological outcomes achieved return of spontaneous circulation within 35 minutes of EMS-initiated CPR.
"Our finding that the likelihood of surviving with a favorable neurological outcome declines with each minute of CPR indicates that the time from cardiac arrest to CPR is a crucial factor in determining whether a patient will return to a normal life," Dr Goto said. "This implies that we need to start CPR as soon as possible. We hope our findings give EMS personnel and clinicians the confidence that if they stop CPR after 35 minutes they have done everything they can do for a patient. This should help them know when it is appropriate to move on to the next medical emergency."