The impact of deep and moderate body temperatures on end-organ function during hypothermic circulatory arrest

作者：Khaladj Nawid^*; Peterss Sven; Pichlmaier Maximilian; Shrestha Malakh; von Wasielewski Reinhard; Hoy Ludwig; Haverich Axel; Hagl Christian

来源：European Journal of Cardio-Thoracic Surgery, 2011, 40(6): 1492-1499.

DOI：10.1016/j.ejcts.2011.03.031

• Hypothermic circulatory arrest
• Temperature
• Reperfusion injury
• Animal model

Objective: Hypothermic circulatory arrest (HCA) at different temperatures is a protection technique for operations involving the aortic arch. In combination with selective cerebral perfusion, higher arrest temperatures for the remaining body may be permitted. However, the ischaemic/reperfusion injury (I/R) in various organ systems, other than the brain, related to the specific HCA temperature has so far not been evaluated. Methods: Fourteen pigs were randomly assigned to 60 min of sole HCA at 20 or 30 degrees C temperature, weaned from cardiopulmonary bypass (CPB) and followed 4 h after HCA. Besides complex haemodynamic monitoring, laser-Doppler spectrophotometry for measuring capillary blood flow, tissue oxygen saturation and post-capillary venous filling pressures of the bowel was installed. At the end of experiment, organs were perfusion fixated and harvested. Results: During the entire experiment, haemodynamics revealed no differences between the groups. CPB bypass times were 177 +/- 12 min in the 20 degrees C and 158 +/- 11 min in the 30 degrees C group, respectively (p = 0.02). During reperfusion, lactate levels were initially significantly higher in the 30 degrees C animals (p = 0.001) but subsequently declined. Microcirculatory blood flow and velocity in the bowel were significantly reduced during cooling and reperfusion (p < 0.05), but were independent of final HCA temperature. Histological evaluation revealed significantly more oedema formation in the bowel wall of the 30 degrees C animals (p = 0.05). Conclusions: Higher levels of circulating lactate levels during reperfusion indicate less effective organ protection at 30 than at 20 degrees C after 60 min of HCA. This is further substantiated by histological evidence for a more pronounced oedema inflammatory response within the bowel wall.

• 出版日期2011-12