Background Neuromuscular blockers used to prevent shivering during therapeutic hypothermia in comatose patients after out-of-hospital cardiac arrest are associated with adverse events. Objective To assess the influence of a nurse-implemented protocol on use of neuromuscular blockers in patients treated with 24-hour therapeutic hypothermia after out-of-hospital cardiac arrest. Methods A before and after study was done in a 24-bed cardiac arrest center. During the before period, paralysis was maintained by continuous infusion of vecuronium during therapeutic hypothermia. During the after period, a nurse-implemented protocol was used to strictly control use of neuromuscular blockers. The primary outcome measure was duration of infusion of neuromuscular blockers; secondary end points included rates of ventilator-associated pneumonia and intensive care unit mortality. Results Among the 22 patients in the before group and the 23 patients in the after group, most were men (78%) with a median age of 66 years. Baseline characteristics were similar between the 2 groups. Median duration of sedation was 36 hours, shorter in the after group (34 hours) than in the before group (38 hours; P = .02). Median duration of infusion of neuromuscular blockers was significantly shorter in the after group (6 hours) than in the before group (33 hours; P < .001). Ventilator-associated pneumonia occurred more frequently in the before group (45%) than in the after group (13%; P = .02). Overall intensive care unit mortality rate was 58%, similar in both groups ( P = .44). Conclusion Use of a nurse-implemented protocol to reduce use of neuromuscular blockers is feasible.