A prospective single-center pilot study to evaluate the feasibility and the safety of venovenous cooling to induce mild hypothermia after cardiac arrest
© BioMed Central Ltd 2005
Published: 7 March 2005
Mild poresuscitative hypothermia improves neurologic outcome after cardiac arrest. Animal studies indicate that rapid induction of the target temperature may be even more neuroprotecive. Currently available methods allow only slow induction of hypothermia (less than 1°C/hour). A faster cooling method could reduce neurologic morbidity and mortality.
We evaluated safety and feasibility of venovenous extracorporal cooling to induce mild hypothermia in a prospective non-randomised single-center clinical study. Eleven patients with witnessed out-of-hospital or inhospital cardiac arrest who remained comatose after the restoration of spontaneous circulation were treated with hypothermia induced with venovenous extracorporal cooling via a double lumen catheter inserted into the v. femoralis. After the induction phase, hypothermia was maintained at 32–34°C for 24 hours with a cooling mattress. The rewarming phase lasted 12 hours. Primary endpoints were the time to reach the target temperature (34°C) and the rate of complications in first 7 days.
Eleven patients were enrolled, age 19–78 years, seven males. Average time to reach a temperature of 34°C was 75 min (range 55–118 min, 95% confidence interval 63–86.5). Cooling averaged 1.97°C/hour (range 1.57–2.58°C/hour, 95% confidence interval 1.76–18°C). No procedure-releated adverse events occured. Four patients (36%) had Glasgow Outcome scale 1–2 14 days after the cardiac arrest.
Extracorporeal venovenous cooling is a safe and fast method for induction of mild hypothermia in patients who underwent cardiac arrest. To prove the hypothesis that the faster the induction of hypothermia the better neurologic outcome, a much larger study is needed.