Imatinib and Chronic-Phase Leukemias

Therapeutic Hypothermia after Cardiac ArrestTo the Editor: The results of two studies reported in the Journal (Feb.21 issue) 1,2 suggest that therapeutic hypothermia has a beneficial effect on neurologic outcome in survivors of out-of-hospital cardiac arrest.The authors of the accompanying editorial 3 support the conclusions of these studies and firmly recommend the use of hypothermia for at least 12 hours after cardiac arrest.Before this complex intervention becomes accepted as standard therapy, a closer examination of these studies is warranted.The authors of both studies cite problems in study design and in the interpretation of their results, but neither they nor the authors of the editorial acknowledge a flaw in both studies that should cast considerable doubt on the results and conclusions.Factors known to be of prognostic importance after cardiac arrest are the brain-stem reflexes and motor responses immediately after resuscitation. 4,5 In this regard, neither study presents data reflecting the depth or severity of coma before randomization.Without these data, there is no reassurance that the hypothermia and normothermia groups were well matched according to the severity of the neurologic insult, thus raising the possibility of bias.Although arrest and resuscitation times correlate with the severity of the neurologic insult and with mortality, they cannot be used as proxies for the neurologic examination.Furthermore, the small number of patients in these trials precludes any assumption that randomization would compensate for the noted deficiencies.It is premature to conclude that therapeutic hypothermia is effective or that it can be recommended for use in comatose survivors of cardiac arrest.