Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies

Department Chair

John Cavenagh, PhD, PA-C


OBJECTIVE: The objective of this selective EBM review is to determine whether or not prehospital therapeutic hypothermia improves the functional and survival status of post cardiac arrest patients.

STUDY DESIGN: Review of three English language primary studies, two of which were published in 2007 and one in 2010.

DATA SOURCES: Two randomized, controlled, clinical trials and one cohort study comparing pre-hospital therapeutic hypothermia to induction of therapeutic hypothermia upon hospital admission, and to standard normothermic post cardiac arrest care. All were found using Medline, OVID, and Cochrane Systematic databases.

OUTCOMES MEASURED: An outcome measured was functional status at hospital discharge, defined by cognitive function and neurophysical outcomes. Survival status was also evaluated and based on whether patients became conscious, were discharged from the hospital alive, or whether they expired.

RESULTS: Kim and Tiainen et al demonstrated that therapeutic hypothermia may improve survival status and improve functional status respectively for patients with an initial rhythm of ventricular fibrillation when compared to patients who received standard normothermic post cardiac arrest care. Both studies, however, failed to show conclusive statistical significance supporting the benefits of therapeutic hypothermia. Bernard et al reported improved functional outcomes in patients who received cooling upon hospital admission compared to pre-hospital cooling, but similarly, results were not statistically significant. All methods used were determined to be feasible for out-of-hospital use and to decrease core body temperature. Additionally, methods were not associated with adverse outcomes such as cognitive decline or pulmonary edema.

CONCLUSIONS: The results of the three clinical trials show that there is inconclusive evidence that pre-hospital therapeutic hypothermia improves the functional and survival status of patients following cardiac arrest. Two of the three trials report an increased occurrence of favorable outcomes for patients treated with pre-hospital therapeutic hypothermia. This data supports that further studies with adequate sample sizes, improved compliance, and more rapid and adequate induction of cooling should be considered to determine if this treatment could significantly improve patient outcomes.