Inducing hypothermia to decrease neurological deficit: literature review.

Abstract

AIM: This paper reports a literature review to examine the effectiveness of inducing hypothermia to decrease neurological deficit after out-of-hospital cardiac arrest. BACKGROUND: After cardiac arrest, severe neurological impairment is a major problem. Outcome after anoxic brain injury following cardiac arrest varies from normal function to brain death. However, a large proportion of these patients are left with severe disability and completely dependent on others for basic needs. Since the 1950s, several studies have shown how hypothermia can be neuroprotective. Recently, these studies have been taken to human trials in populations experiencing out-of-hospital cardiac arrest. METHODS: A literature search was conducted using the Ovid and MDConsult databases for the years 1966-2004 and the keywords included hypothermia, therapeutic hypothermia, and cardiac arrest. Only English language papers were retrieved. Six human trials were found. RESULTS: All six studies showed improved neurological outcomes and four of these showed a decrease in mortality. Minimal complications exist from inducing mild hypothermia after cardiac arrest, and include decreased heart rate, increased systemic vascular resistance, transient electrolyte abnormalities (increased serum potassium and glucose), possible increase in pneumonia or other infectious processes, possible rebound hyperthermia, possible hypotension, and possible arrhythmias. CONCLUSIONS: Based on the review of these studies and the recommendations from the Advanced Life Support Task Force of the International Liaison Committee on Resuscitation, advanced practice nurses should promote this practice, but look for further research on specific treatment recommendations.