Therapeutic Hypothermia: Is It Effective for Non-VF/VT Cardiac Arrest?

Abstract

Sudden cardiac death represents a major health problem. In adults, the prevalence of out-of-hospital cardiac arrest (OHCA) attended by the emergency medical services (EMS) ranges from 52 to 112 per 100,000 person-years in developed countries [1], whereas the prevalence of adult in-hospital cardiac arrest (IHCA) ranges from 1 to 5 per 1,000 patient admissions [2].Mortality from cardiac arrest exceeds 90 % in OHCA [1,3] and 70 % in mo st studies on IHCA [4][5][6]. Patients who have a sh ock able rhythm, i. e., ventricular fi brillation (VF) or pulseless ventricular tachycardia (VT), on initial electrocardiogram (EKG) have a consistently higher survival than those whose initial cardiac rhythm is nonshockable, i. e., asysto le or pulseless electrical activity (PEA).More than two-thirds of initially resuscitated patients die before hospital discharge [7,8]. Th e m ajor causes of hospital mortality are post-resuscitation brain and myocardial dysfunction [9,10]. Mild therapeutic hypothermia can reduce the sever ity of post-resuscitation brain injury and improve survival in patients who remain comatose after resuscitation from cardiac arrest. In 2002, two randomized clinical trials showed improved neurological outcome [11,12] in a t otal of 350 comatose adults resuscitated from OHCA who were cooled to 32-34°C for 12-24 hours shortly after recovery of spontaneous circulation. Th e largest of these trials [12] also sh owed a signifi cant reduction in mortality within six months in patients treated with mild therapeutic hypothermia. Both these trials included only patients who had VF/VT as the initial rhythm.Based on these results, subsequently confi rmed by a meta-analysis [13] Hypothermia for non-VF/ VT cardiac arrestTh e evidence on whether use of mild therapeutic hypothermia could improve prognosis in comatose patients resuscitated from non-VF/VT cardiac arrest is sparse. We identifi ed 15 observational studies (Table 1) and 2 randomized trials. Randomized clinical trialsUse of mild therapeutic hypothermia for the treatment of patients resuscitated from non-VF/VT cardiac arrest has been described in two randomized trials, even thou gh neither was specifi cally designed to assess the benefi t of mild therapeutic hypothermia in this patient population. One trial was a feasibility study on a helmet device for inducing hypothermia after resuscitation [19], the other examined the eff ect of isovolemic high-volume hemofi ltrati on alone or combined with mild therapeutic hypothermia to improve survival after cardiac arrest [20]. Th ese trials included a total of only 44 patients with non-VF/VT rhythms. Within this small subgroup, patients treated with mild therapeutic hypothermia had a higher survival rate at six months than did controls (5/22 © 2010 BioMed Central Ltd Therapeutic hypothermia: is it eff ective for non-VF/VT cardiac arrest?Claudio Sandroni*, Fabio Cavallaro, Massimo Antonelli This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2013 and co-published as a ...

Predictors of Survival and Favorable Functional Outcomes After an Out-of-Hospital Cardiac Arrest in Patients Systematically Brought to a Dedicated Heart Attack Center (from the Harefield Cardiac Arrest Study)

“…22e24 These findings have not been consistently demonstrated in observational studies. 25 We found therapeutic hypothermia to be an independent predictor of short-and long-term survival. Prehospital advanced airway use was associated with worse functional outcomes, in keeping with previously reported findings.…”

Good outcome in every fourth resuscitation attempt is achievable—An Utstein template report from the Stavanger region

“…This outcome mirrors previous reports of lower expected survival rates and a decreased effect of TH treatment in this patient group. [178][179][180] In Norway, the use of TH is also recommended in OHCA patients with non-shockable first rhythms [69], but only 50% of these patients received TH treatment. These findings demonstrate the continuous need for further studies in OHCA populations and for subgroup analyses.…”

“…These findings demonstrate the continuous need for further studies in OHCA populations and for subgroup analyses. [178,179,181] Older age predicted the less-frequent use of TH and worse survival. This phenomenon is also found in previous research, indicating that older age might be an independent predictor of reduced efficacy of TH treatment.…”

Controversies in the temperature management of critically ill patients

“…The widespread use of the implantable cardioverter-defibrillator might cause this ratio to decline even further over time [36]. However, indications for therapeutic hypothermia in non-VF and VT patients remain unclear, and large randomized controlled trials might encounter difficulties in enrolling >1,000 patients, as non-VF and VT patients are resistant to returning to spontaneous circulation, and <10 % of these patients survive to be discharged from the hospital [37][38][39][40][41].…”