Re-arrest immediately after return of spontaneous circulation: A retrospective observational study of in-hospital cardiac arrest.

BACKGROUND

Patients who achieve return of spontaneous circulation (ROSC) after in-hospital cardiac arrest (IHCA) may re-arrest. This phenomenon has not been sufficiently investigated. The aim of this study was to examine the immediate (1-min) and short-term (20-min) risks of re-arrest in IHCA.

METHODS

We retrospectively analyzed four datasets of IHCA episodes, comprising defibrillator recordings collected between 2002 and 2022. Re-arrest was defined as the resumption of chest compressions following a period of ROSC after cardiac arrest of any duration. Parametric models were applied to calculate the immediate risk of re-arrest. In addition, we estimated the short-term risk of re-arrest within 20 min.

RESULTS

In 763 episodes of IHCA, we observed 316 re-arrests: 68% to pulseless electrical activity (PEA), 25% to ventricular fibrillation/ventricular tachycardia (VF/VT), and 7% to asystole. Most re-arrests occurred with the same rhythm as in the initial arrest. When ROSC was achieved from a non-shockable rhythm, the risk of re-arrest to a non-shockable rhythm was initially 2% per minute and decreased to 1% per minute after 9 min. The corresponding risk of re-arrest to VF/VT was constant at 2% per minute. If ROSC was obtained from a shockable rhythm, the risk of re-arrest to a shockable rhythm was initially 5% per minute, decreasing to 4% per minute after 9 min. The corresponding risk to a non-shockable rhythm was constant at 1% per minute. The risk of re-arrest within 20 min was 27%, and the overall risk of at least one re-arrest per episode was 33%.

CONCLUSIONS

The immediate risk of re-arrest was approximately 2% per minute, with the highest risk occurring as a reversion to VF/VT if ROSC was obtained from VF/VT. The risk of re-arrest within 20 min of the initial arrest was 27%, and the overall risk of at least one re-arrest per episode was 33%.