Background: Out-of-hospital cardiac arrest (OHCA) is the third leading cause of death in Europe, with a high burden of disability for patients and their families [¹]. When the heart stops, the body and brain cells quickly deplete of oxygen. Without intervention, brain damage occurs rapidly, and death is inevitable. Unfortunately, the prognosis for OHCA patients remains poor, even when return of spontaneous circulation (ROSC) is achieved. Only a few (less than 10%) of OHCA patients can be discharged from the hospital, and only two-thirds of these are discharged with a good neurologic outcome to lead an independent life [¹].

Reperfusion injury starts immediately following ROSC. Multiple pathophysiologic cascades lead to reactive astrogliosis and microglia activation and neuronal death by necrosis and apoptosis. This is one of the key component of what has been described as ‘post-resuscitation syndrome’ [²]. Mild hypothermia in the temperature range of 32 to 34°C was shown to mitigate these different pathophysiologic cascades simultaneously, efficiently limiting brain cell damage [³]. Numerous animal studies confirmed the beneficial effect of mild hypothermia [⁴]. In 2002, two landmark randomized clinical trials (RCT) in patients after cardiac arrest with shockable rhythm showed improved neurological outcomes following treatment with mild hypothermia in the range of 32 to 34°C compared to no temperature control [^5,6]. As a result of these studies, in 2005, the European Resuscitation Council (ERC) guidelines recommended the use of mild hypothermia in the range of 32 to 34°C for 24 h in unconscious adults resuscitated following out-of-hospital cardiac arrest with a shockable rhythm; for non-shockable rhythm and in-hospital cardiac arrest, temperature control was suggested as a weak recommendation [⁷].

Click here to read the full article.