Gentile B J, Szlyk-Modrow P C, Sils I V, Krestel B A, Tartarini K A, Francesconi R P
Comparative Physiology Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760-5007, USA.
Aviat Space Environ Med. 1995 Feb;66(2):143-7.
Central arterial hemodynamic changes were assessed during cooling, hypothermia, and rewarming in splenectomized (SPX, n = 4) and unsplenectomized (SP, n = 4) 8-10 month old male Yucatan miniature swine (34.0 +/- 1.4 kg). Under isoflurane anesthesia, and using circulating-water blankets, pigs were cooled to and then maintained for 2 h at a rectal temperature (Tre) of 27 +/- 1 degrees C; hypothermia was followed by rewarming to normothermia (37 +/- 1 degrees C). There were significantly (p < or = 0.05) greater changes in central arterial hematocrit and hemoglobin (delta HCT and delta HGB) from respective precooling baseline levels in the SP group during hypothermia and early rewarming (SP: delta HCTmax = 9-10%RBC, and delta HGBmax = 3.0-3.5 g/dl vs. SPX: delta HCTmax = 3-4%RBC, and delta HGBmax = 1.5-1.8 g/dl). By the end of rewarming, splenic resequestration and extravascular fluid shifts resulted in these values returning to baseline. In addition, cardiovascular instability was seen in the SPX group compared to the SP animals as evidenced by significant tachycardia and hypotension during rewarming. We have concluded from these studies that hypothermia causes significant hemoconcentration, and that splenic contraction is the major cause of this hemoconcentration during hypothermia and initial rewarming in miniature swine. A splenectomized design should be considered for swine studies that purport to pattern human pathophysiology, especially for modelling rewarming shock.
在脾切除（SPX，n = 4）和未脾切除（SP，n = 4）的8 - 10月龄雄性尤卡坦小型猪（34.0 +/- 1.4 kg）的降温、低温和复温过程中，评估了中心动脉血流动力学变化。在异氟烷麻醉下，使用循环水毯，将猪冷却至直肠温度（Tre）27 +/- 1℃，然后维持2小时；低温后再复温至正常体温（37 +/- 1℃）。在低温和早期复温期间，SP组的中心动脉血细胞比容和血红蛋白（ΔHCT和ΔHGB）相对于各自的预冷基线水平有显著（p≤0.05）更大的变化（SP：ΔHCTmax = 9 - 10%RBC，ΔHGBmax = 3.0 - 3.5 g/dl vs. SPX：ΔHCTmax = 3 - 4%RBC，ΔHGBmax = 1.5 - 1.8 g/dl）。复温结束时，脾脏再扣押和血管外液体转移导致这些值恢复到基线。此外，与SP动物相比，SPX组出现了心血管不稳定，表现为复温期间显著的心动过速和低血压。我们从这些研究中得出结论，低温会导致显著的血液浓缩，并且脾脏收缩是小型猪低温和初始复温期间这种血液浓缩的主要原因。对于旨在模拟人类病理生理学的猪研究，尤其是模拟复温休克的研究，应考虑采用脾切除设计。
