EARLY THERAPEUTIC HYPOTHERMIA FOR CARDIAC ARREST

Early Therapeutic Hypothermia Improve Survival Rate By a Cardiac Arrest

Early Therapeutic Hypothermia Improve Survival Rate By a Cardiac Arrest

Introduction

Cardiac arrest is an important public health problem. The incidence of out-of-hospital cardiac arrest (OHCA) in North America is between 0.53 and 0.91 per 1000 population, (Nolan et al 2003) and only about 8% of these patients survive. Therapeutic hypothermia involves cooling comatose patients to a temperature of 32-34 °C for a period of 12-24 h after they are successfully resuscitated from cardiac arrest. This therapy has been shown to improve survival in patients who have return of spontaneous circulation (ROSC) but remain comatose after OHCA.

Discussion

A metaanalysis using individual patient data from 3 studies demonstrated that the number needed to treat was only 6 patients to allow one additional person to survive to hospital discharge with good neurological function (Bernard Gray and Buist et al., 2002). This study included patients with all cardiac arrest rhythms, but the vast majority (>91%) had ventricular fibrillation or pulse less ventricular tachycardia.

Treatment with mild hypothermia (33 °C) induced after cardiopulmonary resuscitation (CPR) is recommended for treatment of neurological injury following prolonged out-of-hospital cardiac arrest, based on the analysis of two randomised, controlled clinical trials. However, the optimal timing and technique of induction of hypothermia remain uncertain. Laboratory studies in animal models have suggested that outcomes may be further improved if hypothermia is induced during CPR.

Out-of-hospital cardiac arrest is common and associated with a poor prognosis, with less than 3% of patients surviving to good outcome at hospital discharge. Patients who are initially successfully resuscitated by emergency medical services often remain unconscious because of severe anoxic brain injury (Pichon et.al. 2007). Recently, clinical trials of induced hypothermia (IH) have shown improved outcome in comatose survivors of out-of-hospital cardiac arrest.

Secondly, the covering of the patient with ice packs or cooling blankets during resuscitation is inconvenient for medical and nursing staff. Finally, the use of ice packs or refrigerated units (for forced air cooling) limits the use of these techniques to the hospital environment.

Based on this evidence and international expert consensus, the International Liaison Committee on Resuscitation (ILCOR) and the American Heart Association recommend therapeutic hypothermia for patients with ROSC after cardiac arrest. However, research has suggested that therapeutic hypothermia is still poorly applied in practice. We sought to evaluate Canadian emergency and critical care physician self-reported adoption of therapeutic hypothermia and to determine physician and practice characteristics that are associated with adoption. Our secondary objectives were to determine what methods Canadian physicians are using to cool patients and perceived barriers to using this treatment.

Factors Associated With Reported Adoption of Therapeutic Hypothermia

We identified several characteristics that were strongly predictive of adopting therapeutic hypothermia for patients after cardiac arrest (Wolfrum et.al. 2007). These included working in a hospital with a cooling protocol, being a critical care specialist, treating more than 10 cardiac arrests per year, and being in practice for less than 10 years.

Our analysis are consistent with research suggesting that protocols or standardized pre-written ...