A comparison of complications during therapeutic hypothermia between surface cooling and endovascular cooling techniques

Introduction

Therapeutic hypothermia (TH) following cardiac arrest is associated with several complications including symptomatic bradycardia, coagulopathy, and pneumonia [1]. Furthermore, hyperthermia is associated with poor outcome following brain injury. The incidence of these complications may be increased by excessive temperature fluctuations. We sought to compare complications between two techniques used to induce TH; surface cooling (SC) using ice packs, and endovascular cooling (EV), using the Coolgard™ system (Alsius Corp., USA).

Methods

A retrospective review was performed of all cardiac arrest patients undergoing TH and surviving ≥48 hours between June 2005 and November 2006.

Results

Thirty-five patients underwent our TH protocol (SC group = 21, EV group = 14). The incidence of overcooling (<32°C) in the SC group was significantly higher than the EV group (10 vs 1, P = 0.01), whilst a trend towards more episodes of symptomatic bradycardia (SC 9 vs EV 2, P = 0.07) and rebound hyperthermia (SC 9 vs EV 2, P = 0.07) was also present. The incidence of pneumonia (SC 7 vs EV 4, P = 0.77) and coagulopathy/bleeding (SC 2 vs EV 3, P = 0.32) were similar between groups.

Conclusion

(1) SC is associated with a significantly higher incidence of overcooling than EC and may be associated with an increase in complications such as symptomatic bradycardia. (2) SC may also be associated with an increase in rebound hyperthermia.