When, where and how to initiate hypothermia after adult cardiac arrest

Therapeutich hypothermia (TH) has been shown to improve neurological outcome and survival after witnessed cardiac arrest (CA) that is due to ventricular fibrillation. Although TH is widely used following witnessed CA as well as all forms of initial rhythm, the mortality rate after CA remains unacceptably high, and additional study is needed to understand when and how to implement hypothermia in the post-resuscitation phase. Experimental studies have emphasized the importance of initiating cooling soon after the return of spontaneous circulation (ROSC) or even during cardiopulmonary resuscitation (CPR). Clinical studies have shown that pre-hospital induction of hypothermia is feasible and has no major adverse events-even when used intra-arrest-and may provide some additional benefits compared to delayed in-hospital cooling. Thus, hypothermia use should not be limited to the Intensive Care Unit but can be initiated in the field/ambulance or in the Emergency Department, then continued after hospital admission- even during specific procedures such as coronary angiography-as part of the global management of CA patients. Various methods (both non-invasive and invasive) are available to achieve and maintain the target temperature; however, only some of these methods-which include cold fluids, ice packs, iced pads and helmet and trans-nasal cooling- are easily deployed in the pre-hospital setting.