Induction of therapeutic mild hypothermia after cardiac arrest: a new combined method to achieve the target temperature

Background

Clinical and experimental investigations have demonstrated that induction of mild hypothermia works after successful cardiopulmonal resuscitation (CPR) neuroprotection. After the presentation of controlled studies, therapeutic hypothermia moved into the topical international guidelines.

Methods and results

A total of 50 patients were examined after successful CPR. Twenty-nine patients received 4°C cold infusions after arrival in the heart catheter laboratory. Retrospective data of 21 patients who had received a volume substitute by means of drips from ambient temperature served as a control group. After admission to the ICU, both groups were immediately connected to an external cooling device (CoolGard^® or Thermo Wrap^®) and were cooled to a target temperature of 33°C (bladder temperature).

Results

The average temperature at admission did not differ in both groups (35.5 ± 0.9°C vs 35.89 ± 0.8°C). In the group with initial cooling by means of 4°C cold infusions, a significant temperature decrease could be reached during the invasive coronary diagnostics to admission to the ICU of an average 0.84°C (35.88 ± 0.9°C vs 35.04 ± 0.9°C, P < 0.0001). The middle chill duration up to the achievement of the target temperature after admission was significantly shorter with the combined method (341 ± 113 min versus 553 ± 342 min, P < 0.01). The period to the achievement of the target temperature after the beginning of the external cooling device with the group of the combined method was significantly shorter (163 ± 91 min versus 342 ± 258 min, P < 0.01).

Conclusion

The combined method with initial cooling with 4°C cold solutions shows a sure and actual prestationary cooling procedure to the introduction or realisation of mild hypothermia and offers the possibility to reach the purpose temperature significantly faster. Preclinical introduction of mild hypothermia by means of 4°C cold solutions could be a beneficial criteria in the future treatment, and probably affects the outcome of these patients.