Beger S, Sutter J, Vadeboncoeur T, et al. - Researchers examined how patient sex, age, weight, and time in resuscitation determine chest compression release velocity (CCRV) during prehospital resuscitation from out-of-hospital cardiac arrest (OHCA). They analyzed data of 1,140 adult OHCA cases from two suburban EMS agencies in Arizona. They identified that during the first 10 min of CPR, the median duration of recorded compressions was 8.70 min. Even after adjusting for compression depth, they observed a decline in CCRV. For minutes 0–5 vs minutes 5–10, the individual-level mean CCRV was higher. Males vs females showed a greater mean CCRV. They observed a negative correlation of mean CCRV with age and a positive correlation with patient weight.