The effects of moderate hypothermia on energy metabolism and serum inflammatory markers during laparotomy

Abstract

The objective of this study was to investigate energy metabolism of the gut and liver as well as serum inflammatory cytokines following exploratory laparotomy at moderate hypothermia. Two groups of rats were studied, (n=6-8/group); laparotomy at normothermia for 120 min and laparotomy at hypothermia (32-33 degrees C) for 120 min. Study 1: Intestinal glucose, succinate, lactate, phosphocreatine, and ATP as well as hepatic glucose, succinate, lactate, and ATP were measured in terms of micromole per gram using magnetic resonance spectroscopy. Study 2: Serum levels of TNF-alpha, IL-1beta, LPS-inducible chemokine (LIX), and sICAM-1 were measured by ELISA. Histology of the gut and liver were interpreted. Data are expressed as mean and SEM. In Study 1, laparotomy at hypothermia caused an increase in intestinal glucose levels (0.78+/-0.03 vs. 1.29+/-0.11, P=0.0012) with a decrease in hepatic lactate levels (0.82+/-0.04 vs. 0.44+/-0.06, P<0.001). There were no differences in the other metabolites between the two groups. In Study 2, there were no differences in serum TNF-alpha, IL-1beta, LIX, or sICAM-1 between the two groups. Histological features of the gut and liver among groups were comparable. In conclusion, the intestine and liver react to hypothermia differently. However, levels of high-energy phosphates in both organs are not affected by hypothermia suggesting adequate energy for the organs. It is unlikely that hypothermia induces either systemic inflammatory response or hypoxic damage to the intestine and liver in this model.

Topic liver hypothermia and ischemic preconditioning: a new model of ischemia and reperfusion in rats

“…Up until now there is no consensus about the best level of temperature which should be applied, but a set of evidences points that a mild or moderate hypothermia is able to confer protection to the liver 4,17,18 . The main mechanism of protection postulated is a decrease of cellular metabolism and oxygen requirement, which occurs consequent to hypothermia, preserving energy and allowing a longer period of inflow occlusion 5,17,19 . However, the IPC also has been related to a lesser demand of energy and this is one of the mechanisms attributed to the liver protection 20 .…”

“…Even with the strong evidence of benefits in the liver and other target-organs 21 , the use of body hypothermia has been limited because the risks of inducing hemodynamic disturbances, coagulopathy, metabolic acidosis and arrhythmias 19 . In addition, the technique of in situ liver perfusion is complex, demanding total vascular exclusion and veno-venous by-pass 7,22,23 .…”

Hypothermia: Novel approaches for premature infants

“…Additional research in the same model has shown that hypothermia decreases the elevation of serum soluble intercellular adhesion molecule-1 (sICAM), presuming that hypothermia blunts tissue injury 22. Moderate hypothermia in the rat NEC model during laparotomy does not appear to affect energy metabolism 23. Finally, an animal model of intestinal ischemic and reperfusion with mild hypothermia to 32 to 33.0°C decreases intestinal injury and other organ dysfunction 24.…”