In Reply Drs Dell’Anna and Taccone propose 3 potential explanations for the lack of survival and neurological benefit in our study of the use of a rapid infusion of 4°C normal saline in patients resuscitated from out-of-hospital cardiac arrest: (1) underuse of in-hospital therapeutic hypothermia, (2) adverse hemodynamic effects of fluid infusion, and (3) a modest temperature difference between the control and intervention groups.
First, Dell’Anna and Taccone note that 74% of randomized patients with ventricular fibrillation and 59% without ventricular fibrillation reached a target temperature of less than 34°C. There are several reasons for this. Some patients did not survive long enough to receive cooling, some patients did not have cooling started by hospital staff due to known contraindications to cooling, and some patients did not have cooling ordered or started by the staff. We do not believe that uniform use of hospital therapeutic hypothermia would alter the primary results in either rhythm cohort because randomization was stratified by receiving hospital and first rhythm to try and balance any differences in hospital use rates of therapeutic hypothermia. Importantly, the use rate of therapeutic hypothermia was equal between the treatment and control groups. Use of therapeutic hypothermia in patients with ventricular fibrillation in our study was high compared with use of therapeutic hypothermia by others.1
Kim F, Maynard C, Nichol G. Prehospital Therapeutic Hypothermia in Patients With Out-Of-Hospital Cardiac Arrest—Reply. JAMA. 2014;311(21):2233-2234. doi:10.1001/jama.2014.2679