Hanhela R, Hollmen A, Huttunen P, Hirvonen J
Department of Anaesthesiology, University of Oulu, Finland.
Acta Physiol Scand. 1990 Jul;139(3):441-9. doi: 10.1111/j.1748-1716.1990.tb08945.x.
Venous plasma noradrenaline, adrenaline, dopamine, corticosterone, glucose and free fatty acid concentrations were measured in anaesthetized rabbits during hypovolaemia, hypothermia and a combination of these. The anaesthetic used was Hypnorm, which contains fentanyl and fluanisone. In the hypovolaemia group blood was shed via the venous cannula until the mean arterial pressure was 50 mmHg. The rabbits in the hypothermia group were cooled in iced water to a central temperature of 32 degrees C, and the rabbits in the combined hypovolaemia-hypothermia group were bled until hypovolaemic and then cooled in iced water to a central temperature of 32 degrees C. Rewarming was done in dry air at 43 degrees C. Bleeding and hypothermia activated the sympathicoadrenal system, causing a rise in the noradrenaline and adrenaline concentrations, as well as a rise in corticosterone. There were no significant differences in plasma noradrenaline and adrenaline values between the groups, whereas hypovolaemia alone also increased the dopamine concentration. In the hypothermia group the amount of corticosterone after cooling and rewarming was higher than in the combined group. Hypothermia and hypovolaemia increased the level of free fatty acids and blood glucose, which in the hypovolaemia group remained higher after volume replacement than in the other groups. Hypothermia in both groups increased the mean arterial pressure. In conclusion, the results suggest that hypothermia may prevent some harmful effects of hypovolaemia, e.g. by correcting mean arterial pressure, thus preventing the mortality seen in the hypovolaemia group.
在麻醉兔处于低血容量、低温以及二者合并状态时，测定其静脉血浆中去甲肾上腺素、肾上腺素、多巴胺、皮质酮、葡萄糖和游离脂肪酸的浓度。所用麻醉剂为含芬太尼和氟哌利多的海洛因。低血容量组通过静脉插管放血，直至平均动脉压降至50 mmHg。低温组的兔置于冰水中冷却至中心体温32℃，低血容量合并低温组的兔先放血至低血容量状态，然后置于冰水中冷却至中心体温32℃。在43℃的干燥空气中进行复温。放血和低温激活了交感肾上腺系统，导致去甲肾上腺素和肾上腺素浓度升高，同时皮质酮也升高。各组间血浆去甲肾上腺素和肾上腺素值无显著差异，而单纯低血容量也会使多巴胺浓度升高。低温组冷却和复温后的皮质酮含量高于合并组。低温和低血容量会使游离脂肪酸和血糖水平升高，在低血容量组，补液后这些指标仍高于其他组。两组中的低温均使平均动脉压升高。总之，结果表明低温可能预防低血容量的一些有害影响，例如通过纠正平均动脉压，从而防止低血容量组出现的死亡情况。
