Comparison of surface cooling and invasive cooling for rapid induction of mild therapeutic hypothermia in pigs—Effectiveness of two different devices

Aim of the studyThe effectiveness and safety of non-invasive surface cooling was compared to invasive endovascular cooling in an animal model.MethodsEight healthy pigs (29–38 kg) were cooled twice, starting in the first 4 pigs with unique surface cooling pads followed by endovascular cooling. In the second 4 pigs the order was reversed. The goal was to quickly lower pulmonary artery temperature from 38 to 33 °C. A paired t-test was used to compare cooling rates (°C/h, mean ± standard deviation) between both cooling techniques.ResultsMean non-invasive surface cooling rate (11.9 ± 3.8 °C/h) significantly exceeded mean invasive cooling rate (3.9 ± 0.7 °C/h; p < 0.001). The mean difference in cooling rates was 8.0 ± 3.6 °C/h. No surface cooling related adverse skin reactions were observed.ConclusionsSurface cooling is a simple method for achieving fast cooling rates. In our animal model, non-invasive cooling was three times faster than rapid endovascular cooling without overshoot.