the article " efficacy of and tolerance to mild induced hypothermia after out - of - hospital cardiac arrest using an endovascular cooling system " by pichon et al . in the previous issue of critical care only 10% of patients undergoing out - of - hospital cardiopulmonary resuscitation are discharged alive from the hospital . this high mortality is to a major part due to ischaemic brain damage . in 2002 , a european multicentre trial on the use of mild therapeutic hypothermia  as well as other clinical trials  clearly demonstrated a decrease in mortality and a better neurological outcome in cardiac arrest patients . only six patients have to be treated to save one life ( number needed to treat = six ) . this is far better than with most other  expensive  approaches in the intensive care unit ( icu ) . consequently , therapeutic hypothermia has been recommended in an advisory statement by the international liaison committee on resuscitation ( ilcor ) already in 2003 . in 2005 , the european resuscitation council ( erc ) guidelines stated : 1 . unconscious adult patients with spontaneous circulation after out - of - hospital ventricular fibrillation cardiac arrest should be cooled to 32 to 34c . cooling should be started as soon as possible and continued for at least 12 to 24 hours . 2 . induced hypothermia might also benefit unconscious adult patients with spontaneous circulation after out - of - hospital cardiac arrest from a non - shockable rhythm , or cardiac arrest in hospital . 3 . a child who regains a spontaneous circulation but remains comatose after cardiopulmonary arrest may benefit from being cooled to a core temperature of 32 to 34c for 12 to 24 hours . therapeutic hypothermia influences postresuscitation brain  and other organ  injury in many different ways : it reduces metabolism , free radical formation , intracellular calcium overload , as well as translation and transcription of pathogenic proteins . additionally , it has anti - apoptotic , anti - inflammatory and anti - coagulatory properties and can reduce oedema formation . there are few areas in emergency and intensive care medicine where scientific evidence is so strong and where international guidelines are so clear . nevertheless , implementation of hypothermia is lousy . in most countries on both sides of the atlantic , under 30% of cardiac arrest patients are receiving hypothermia . colleagues are stating that they do not have enough information and experience , that this therapy is not evidence - based and that it is technically too difficult . mild therapeutic hypothermia is definitely underused post cardiac arrest , and many patients who need not die are dying because of this clinical reality . here pichon and colleagues report on the efficacy and tolerance of a commercially available intravascular cooling device used in 40 post cardiac arrest patients . cooling with this device was safe , relatively fast and effective in maintaining the targeted temperature . regardless of the initial cardiac rhythm  about which the brain does not care  all patient groups benefited from cooling with this device . maintenance of hypothermia is practicable with both surface and endovascular cooling . in the past , very recent data on different techniques of body surface cooling suggest that these techniques are also able to maintain body temperature in a clinically sufficient way . animal experimental data suggest that hypothermia is more effective the faster it is established after the arrest . therefore , the use of other and faster methods to induce hypothermia must be considered . infusion of ice - cold ringer 's solution ( 30 ml / kg within 30 minutes ) has been shown to be an easy , cheap , effective and safe way of inducing hypothermia in less than one hour . this is even possible in the out - of - hospital setting . for subsequent maintenance of hypothermia , intravascular and body surface cooling techniques well known side effects of therapeutic hypothermia , like hypokalaemia , hypomagnesaemia and bacteraemia may occur , and it is important to know this . major complications including arrhythmias , bleeding , pneumonia , sepsis et cetera , however , do not occur more often in hypothermic as compared to normothermic cardiac arrest patients . the most important ' side effect ' of hypothermia is that it is not used routinely in most cardiac arrest patients . according to hippocrates , we have to treat the next unconscious cardiac arrest patient with mild therapeutic hypothermia , regardless of which technique we are using . erc = european resuscitation council ; icu = intensive care unit ; ilcor = international liaison committee on resuscitation .
in 2005 , the european resuscitation council ( erc ) guidelines stated : unconscious adult patients with spontaneous circulation after out - of - hospital ventricular fibrillation cardiac arrest should be cooled to 32 to 34c for 12 to 24 hours . 
 patients with cardiac arrest from a non - shockable rhythm , in - hospital patients and children may also benefit from hypothermia . 
 there is no argument to wait . 
 we have to treat the next unconscious cardiac arrest patient with hypothermia .