LAUSR

Total or partial cooling of human beings has been used sporadically in a variety of diseases of the central nervous system for centuries. Intuitively it is believed that hypothermia may preserve neuronal viability and increase the chances of survival and functional recovery. However, it was not until the last decade that its use has been generalized in a particular situation--recovered cardiac arrests (RCA) after the publication, in the year 2002, of Holzer’s study (HACA group) and Bernard et al.’s study that found out that by inducing mild hypothermia (32--34 ◦C) mortality was lower and the chances of neurological recovery after an out-of-hospital RCA of presumed cardiac origin due to defibrillation rhythms were higher. The recommendation to use hypothermia came fast and it reached out to two groups that had not been evaluated in the clinical trials: non-defibrillation rhythms, and hospital cardiac arrests. As it has happened in other occasions, the desire to find effective therapies in a situation that leads to such higher mortality rates as RCAs is accompanied by an enthusiastic adherence and a not very critical evaluation of the apparently favourable results, so it is not surprising that such studies are usually referred to as ‘‘large sample’’ and ‘‘high quality’’ studies, when they are really small studies with important methodological limitations (Table 1).