Abstract Body: Background
Pediatric out of hospital cardiac arrest (OHCA) causes substantial mortality and morbidity. Hypoxic ischemic brain injury is a major contributor. While efficacious in animal models and neonatal asphyxia, therapeutic hypothermia has unclear benefit following pediatric OHCA. Pediatric ICECAP (Influence of Cooling Duration on Efficacy in Cardiac Arrest Patients) is an ongoing multicenter, multinational, randomized, 10-arm adaptive clinical trial evaluating the impact on one-year neurobehavioral outcome of durations of hypothermic targeted temperature management (TTM) ranging from 12-96 hours or controlled normothermia arm. The maximum sample size is 900. The trial is overseen by a data and safety monitoring board (DSMB) and the United States Food and Drug Administration under an Investigational Device Exemption. A design overview is Figure 1.

Research Questions
The trial goal is to identify the duration which maximizes survival and neurological recovery – as measured by the Vineland Behavioral Adaptive Scale, Third edition (VABS-3) at one year following cardiac arrest.

Aim
We report the baseline characteristics of the first 150 participants from the run-in phase prior to the adaptive randomization phase of the trial.

Methods
Eligible participants are at least 2 days old with OHCA who have received >= 2 minutes of CPR and are intubated with a motor GCS <=5. The P-ICECAP design allocated the first 150 participants equally to 24, 48, or 72 hours durations of cooling to 33 C. These durations were chosen based on prior trials in adults, children, and neonates. We provide summary data for all three cooling durations in aggregate on the baseline characteristics.

Data
Between Summer 2022 and Summer 2024 we enrolled 150 participants. The characteristics are summarized in Figure 2 (Table).

Conclusions
In this initial phase of the first three duration arms of the PICECAP trial, the primary cause of arrest was respiratory in 44% and drowning in 18%. Although most participants have a normal baseline functional status, 49% have preexisting medical conditions. The prevalence of shockable rhythms was higher than previous trials. Only a small percentage of enrolled participants had an initial GCS motor score of 5. No safety concerns have been noted by the DSMB. The adaptive randomization of the trial is now open enrolling all 10 cooling durations.