A comparison between intravascular and traditional cooling for inducing and maintaining temperature control in patients following cardiac arrest

Abstract

Therapeutic temperature control has been widely used during the last decade to improve clinical outcomes. We conducted this retrospective observational study to compare traditional cooling with endovascular cooling in post-cardiac arrest comatose survivors and to compare results with current guidelines.

Patients and methods: All patients admitted to our ICU for cardiac arrest and for whom temperature control was performed were included. Traditional cooling included cold infusions, ice packs and cooling blankets. Endovascular cooling consisted in the insertion of a catheter in which cold fluid circulates in a closed circuit provided by a heat exchanger. Temperature control was started at a target temperature of 32°C to 34°C. Rewarming was performed passively in the traditional group and via computer-assistance in endovascular group. We evaluated the delay prior to and speed of cooling, thermic stability during the maintenance phase and the speed of rewarming.

Results: Thirty-four patients were included. The speed of cooling was faster with the endovascular (-0.66±0.35°C/h) compared to the traditional (-0.35±0.38°C/h, P=0.006) technique, with target temperatures reached in 4.0 and 6.0h, respectively (P=0.14). Temperatures were more stable with the endovascular technique (0.03±0.05°C2) than with the traditional technique (0.26±0.16°C2, P<10^-4). There were more deviations from the guideline target range in the traditional group (64.7% versus 17.6%, P=0.008). Rewarming was faster in the traditional group (+0.64±0.33°C/h, versus +0.36±0.12°C/h, P=0.01). No significant difference was found concerning mortality or length of stay in the ICU.

Conclusion: Temperature control with a cooling catheter was associated with faster cooling, improved thermic stability in the target range, less overcooling or overheating and slower rewarming in comparison with traditional techniques.

Keywords: Cardiac arrest; Intensive care; Mortality; Resuscitation; Temperature control; Therapeutic hypothermia.