Oesophageal thermal tube for intraoperative hypothermia in liver transplantation

Abstract

In order to prevent the occurrence of major hypothermia during liver transplantation, with its deleterious effects on intraoperative cardiovascular activity and on postoperative graft functioning, this study evaluated the benefit of an oesophageal rewarmer, used during surgery, in addition to the usual methods of warming (OR temperature at 22 degrees C, rewarming of fluids and blood, heating mattress, heat and moisture exchanger). We compared 10 patients with an oesophageal rewarmer (OeR group) to 10 patients without (Control group). The anaesthetic procedure was similar in all cases. Rectal (RT) and pulmonary artery (PT) temperatures were recorded during the three phases of surgery (pre-anhepatic, anhepatic, postanhepatic phase) and their time course was analysed with non-parametric tests. The two groups were comparable with regard to duration of surgery, blood and fluid requirements and veno-venous bypass flow rate. The RT decreased similarly in both groups, but was significantly higher in the OeR group at peritoneum closure (P < 0.01). The PT was higher in the OeR group after onset of venous shunting (P < 0.05) and during the third phase of surgery (P < 0.01). Three incidents (one leakage and two herniations of the latex tube) occurred, without detrimental effects on the patients. It is concluded that the oesophageal heat exchanger allows better rewarming after revascularization of the graft, but is unable to prevent cardiac hypothermia at unclamping.

Efficacy of intraoperative heat administration by ventilation with warm humidified gases and an oesophageal warming system

“…There have been several clinical studies on the effects of different warming systems in preventing perioperative hypothermia with controversial results. Both heating of inspired gases and oesophageal warming have been demonstrated as either effective and ineffective in different studies [4][5][6][7][8][9][10][11] . The "within study" and "between studies" variability of the experimental conditions (patients, type of surgery, type of anaesthesia, fluid infusions, room temperature and relative humidity, etc.)…”

“…Several methods are commonly used to reduce body heat loss. Heating inspired gases [4][5][6][7][8] and oesophageal warming [9][10][11] are easily applied during surgery and have been proposed for providing (central) warming, which is probably more "physi-ological" than other methods which deliver heat peripherally (warming the operating room, warm mattresses, thermal blankets, infrared heating lamps, forced air warmers 1-2 12-18 ).…”

Continuous versus intermittent thermodilution cardiac output measurement during orthotopic liver transplantation

“…High levels of thermal noise owing to thermal equilibration between central and peripheral compartments may account for these findings [20,22]. A rapid increase in temperature difference after caval clamping was associated with an overestimation of continuous vs. intermittent cardiac output, while a rapid decrease in temperature difference was associated with an underestimation of it.…”

Efficacy and safety of heat exchanger added to venovenous bypass circuit during orthotopic liver transplantation

“…7 Esophageal thermal tubes are not only ineffective but may be contraindicated in patients with major coagulopathy and portal hypertension. 8 Our experience shows that the use of HEs during OLT effectively normalizes core temperatures at the time of reperfusion. These patients are also significantly warmer several hours later at the end of surgery.…”