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 ...
