Hypothermia protocol for the post cardiac arrest patient has been an evidence based practice of this therapy for about a decade now. This intervention, often used in the critical care setting, is now expanding to primary emergency responders as well. This paper will present some of the notable research that has been done on therapeutic hypothermia, and current use of this intervention.
Control studies, animal studies, and case studies have been published related to these medical interventions. Unfortunately, there are still many healthcare providers not using this intervention. Dainty, Scales, Brooks, Needham, Dorian, Ferguson et al. (2011) study states, “observational research shows that therapeutic hypothermia is delivered inconsistently, incompletely, and often with delay.” In addition a survey that same study found, of Canada and U.S. physicians who replied, only 26% used hypothermia in resuscitated patients (p. 2).
Hypothermia protocol is not universally used at all hospitals, but the facilities that do use it have similar methods. Based on two studies done in 2002 the Advanced Life Support (ALS) Task Force of the International Liaison Committee on Resuscitation (ILCOR) suggested that “unconscious adult patients with spontaneous circulation after out-of-hospital cardiac arrest should be cooled to 32°C to 34°C for 12 to 24 hours when the initial rhythm was ventricular fibrillation (VF)” (Writing Group, Nolan, Morley, Vanden, Hickey, Members of the Advanced Life Support Task Force et al., 2003, p. 118). They also stated it could be beneficial for other rhythms as well. This was the first big step in using hypothermia in the critical care setting. The current protocol still uses that recommendation.
Reducing the body’s temperature decreases cardiac and neurological damage due to ischemia and reperfusion injury. Reperfusion injury is the harmful adverse effects attributed to reestablished circulation (Writing Group et al., 2003). Hypothermia inhibits or reduces normal body functions such as apoptosis and inflammation, and these can often cause additional damage (Torgersen, Bjelland, Klepstad, Kvale, Soreide et al., 2010). Also, by cooling the body to the designated range the metabolic rate slows down and decreases oxygen demand. This allows tissue to avoid ischemia, in particular the brain and heart. The brain is protected in many ways including preserving the blood brain barrier and decreasing harmful free radicals (Wall, 2011).
More recent studies done on animals have been performed in order to manipulate the variables associated with the hypothermia protocol in attempt to solidify the most effective treatment. Although animal studies allow for a more precise scientific method and yield important information, they are not guaranteed to be identical in a human patient. One study involved pigs that underwent a mechanically induced 100% occlusion of the LAD. The results suggested that only early-induced hypothermia,...