Rapid induction of mild therapeutic hypothermia by extracorporeal veno-venous blood cooling in humans

Abstract

Aim: Mild therapeutic hypothermia is beneficial in patients successfully resuscitated from non-traumatic out-of-hospital cardiac arrest. The effect of fast induction of hypothermia in these patients remains to be investigated. The aim of this study was to evaluate the efficacy and safety of extracorporeal veno-venous blood cooling in humans successfully resuscitated from cardiac arrest.

Methods: We performed an interventional study in patients after successful resuscitation from cardiac arrest admitted to the emergency department of a tertiary care centre. The extracorporeal veno-venous circulation was established via a percutaneously introduced double lumen dialysis catheter in the femoral vein, and a tubing circuit and heat exchanger. A paediatric cardiopulmonary bypass roller pump and a heater-cooler system were used to circulate the blood. Main outcome measures were feasibility, efficacy, and safety.

Results: We included eight consecutive cardiac arrest patients with a median oesophageal temperature of 35.9°C (interquartile range 34.9-37.0). A median time of 8 min elapsed (interquartile range 5-15 min) to reach oesophageal temperatures below 34°C, which reflects a cooling rate of 12.2°C/h (interquartile range 10.8°C/h to 14.1°C/h). The predefined target temperature of 33.0°C was reached after 14 min (interquartile range 8-21 min). No device or method related adverse events were reported.

Conclusion: Extracorporeal veno-venous blood cooling is a feasible, safe, and very fast approach for induction of mild therapeutic hypothermia in patients successfully resuscitated from cardiac arrest.

Keywords: Cardiac arrest; Cardiopulmonary resuscitation (CPR); Heart arrest; Induced hypothermia; Resuscitation; Return of spontaneous circulation.