Association between cardiopulmonary resuscitation duration and survival after out-of-hospital cardiac arrest according: a first nationwide study in France.

Objective: Determining whether to pursue or terminate resuscitation efforts remains one of the biggest challenges of cardiopulmonary resuscitation (CPR). No ideal cut-off duration has been recommended and the association between CPR duration and survival is still unclear for out-of-hospital cardiac arrest (OHCA). The aim of this study was to assess the association between CPR duration and 30-day survival after OHCA with favorable neurological outcomes according to initial rhythm.

Methods: This was an observational, retrospective analysis of the French national multicentric registry on cardiac arrest, RéAC. The primary endpoint was neurologically intact 30-day survival according to initial rhythm.

Results: 20,628 patients were included. For non-shockable rhythms, the dynamic probability of 30-day survival with a Cerebral Performance Category (CPC) of 1 or 2 was less than 1% after 25 min of CPR. CPR duration over 10 min was not associated with 30-day survival with CPC of 1 or 2 (adjusted OR: 1.67; CI 95% 0.95-2.94). For shockable rhythms, the dynamic probability of 30-day survival with a CPC score of 1 or 2, was less than 1% after 54 min of CPR. CPR duration of 21-25 min was still associated with 30-day survival and 30-day survival with a CPC of 1 or 2 (adjusted OR: 2.77; CI 95% 2.16-3.57 and adjusted OR: 1.82; CI 95% 1.06-3.13, respectively).

Conclusions: Survival decreased rapidly with increasing CPR duration, especially for non-shockable rhythms. Pursuing CPR after 25 min may be futile for patients presenting a non-shockable rhythm. On the other hand, shockable rhythms might benefit from prolonged CPR.