Use of a heat exchanger in liver transplantation

Of the first 16 patients who underwent orthoptic liver transplantation, 81% were observed to be hypothermic at termination of bypass (x = 34.5 degrees C, n = 16). In response, an in-line heat exchanger was added to the bypass circuit. Subsequently, 72% of the next 11 patients terminated bypass normothermic (x = 38.2 degrees C, n = 11). By removing from the sample those patients who incurred low blood flows, 100% of the patients terminated bypass normothermic (x = 38.2 degrees C, n = 8). At temperatures of 30-33 degrees C cardiac arrhythmias have been observed. Hypothermia has been documented to cause thrombocytopenia and neutropenia which can lead to blood loss. These low counts are only partially reversible with platelet infusion and white blood cells (WBC). The use of an in-line heat exchanger during liver transplantation is essential in preventing hypothermia in our experience.