Intra-arrest cooling using a novel intra-nasal cooling method for immediate induction of therapeutic hypothermia in Germany

Introduction

Recent investigations have demonstrated improved neurological outcome after therapeutic hypothermia in patients after successful resuscitation. The time course and duration to achieve target temperature may be an important factor to influence patient's outcome. To determine the safety and efficacy of intranasal cooling during ongoing resuscitation, for immediate induction of therapeutic hypothermia, the Pre-Resuscitation Intra-Nasal Cooling Effectiveness (PRINCE) study involved 200 patients in Europe, using a non-invasive nasal catheter that sprays evaporating coolant liquid into the nasal cavity. Here we demonstrate data from all German participating sites.

Methods

All patients who were deemed eligible for advance cardiac life support (ACLS) were included as long as the arrest was witnessed and cardiopulmonary resuscitation (CPR) was initiated within 20 minutes of collapse. Patients were randomized to treatment or control groups. The trial was designed to determine the safety and effectiveness of early cooling initiated at the site of arrest. Survival and time to target temperature were documented.

Results

Data are presented as the mean ± SD or median (interquartile range (25, 75%)). Mean age was 67.8 ± 14 years in the intervention group and 65.4 ± 13.9 years in the control group. On average, cooling therapy was started in 33 ± 12 minutes in the RhinoChill™ group and 170 ± 97 minutes in the control group. Temperatures at hospital admission were significant lower in the RhinoChill™ group. Time to target tympanic temperature, reflecting brain temperature, were significant faster in the RhinoChill™ group (211 ± 124 minutes vs 424 ± 217 minutes; P < 0.05). Adverse events occurred in 12 patients. None was related to the cooling therapy. In the intervention group five patients (20%) survived and three patients (12%) had a CPC of 1 to 2. In the control group only four patients (12.5%) survived and one patient (3.1%) had a CPC of 1 to 2.

Conclusions

Using the intranasal cooling method, cooling was much faster and earlier in treated patients. Neurologically intact survival and discharge rates were higher in treated patients. Transnasal cooling for the induction of therapeutic hypothermia during prehospital resuscitation is feasible and highly effective in lowering brain temperature rapidly. The method offers the possibility for immediate introduction and realization of mild hypothermia in the field.