Use of a Standardized Order Set for Achieving Target Temperature in the Implementation of Therapeutic Hypothermia after Cardiac Arrest: A Feasibility Study

Abstract

Induced hypothermia (HT) after cardiac arrest improved outcomes in randomized trials. Current post-cardiac arrest treatment guidelines advocate HT; however, utilization in practice remains low. One reported barrier to adoption is clinician concern over potential technical difficulty of HT. We hypothesized that using a standardized order set, clinicians could achieve HT target temperature in routine practice with equal or better efficiency than that observed in randomized trials. After a multidisciplinary HT education program, we implemented a standardized order set for HT induction and maintenance including sedation and paralysis, intravenous cold saline infusion, and an external cooling apparatus, with a target temperature range of 33-34 degrees C. We performed a retrospective analysis of a prospectively compiled and maintained registry of cardiac arrest patients with HT attempted (intent-to-treat) over the first year of implementation. The primary outcome measures were defined a priori by extrapolating treatment arm data from the largest and most efficacious randomized trial: 1) successful achievement of target temperature for >or=85% of patients in the cohort and 2) median time from return of spontaneous circulation (ROSC) to achieving target temperature <8 hours. Clinicians attempted HT on 23 post-cardiac arrest patients (arrest location: 78% out-of-hospital, 22% in-hospital; initial rhythm: 26% ventricular fibrillation/tachycardia, 70% pulseless electrical activity or asystole) and achieved the target temperature in 22/23 (96%) cases. Median time from ROSC to target temperature was 4.4 (interquartile range 2.8-7.2) hours. Complication rates were low. Using a standardized order set, clinicians can achieve HT target temperature in routine practice.