Physiological Response to a Simplified Veno-Venous Perfusion-Induced Systemic Hyperthermia System

摘要

Our original venovenous perfusion-induced systemic hyperthermia (vv-PISH) system appeared to significantly improve lung cancer patient survival, but was too complex with numerous dialysis problems. We tested a simplified vv-PISH circuit that includes the AvalonElite double lumen cannula, a modified heat exchanger, water heater/cooler, and a centrifugal pump. The purpose of this study was to evaluate this simplified vv-PISH system (without hemodialyzer) and to investigate the physiological response to whole body hyperthermia in pigs. We tested our vv-PISH circuit in healthy female adult swine (n= 7, 55-68 kg). The therapeutic core temperature (42°C), calculated as mean of rectal, bladder, and esophageal temperatures, was achieved in six swine. A maximum difference of 0.5°C was observed between the individual temperature sensor readings, indicating homogeneous heat distribution. Heart rate and mean arterial pressure were transiently altered, but were safely managed. A significant elevation in pulmonary artery pressure occurred during the heating phase, resulting in one pig death. In all other pigs, pulmonary artery pressure returned to physiologic values during the therapeutic phase. Arterial blood electrolytes were maintained without the need of a dialyzer. Major organ function was within normal parameters. The simplified vv-PISH circuit reliably delivered the hyperthermic dose with no need of dialysis.