Taylor K M, Bain W H, Jones J V, Walker M S
J Thorac Cardiovasc Surg. 1976 Jul;72(1):57-61.
The effect of hemodilution on plasma levels of total cortisol and free cortisol was studied in 12 patients undergoing open-heart surgery. In each case, at the onset of extracorporeal circulation (ECC) the hematocrit value was rapidly reduced to 25 to 30 per cent and was maintained around this level during perfusion. Total plasma cortisol levels fell significantly with the hemodilution (p less than 0.0001), but the plasma concentration of free, biologically active cortisol was maintained at its pre-dilution level because of an increase in the percentage of plasma cortisol existing in the free form. There was a highly significant correlation between the degree of hemodilution and the percentage rise in the free cortisol fraction (r = 0.79; p less than 0.001). These results indicate the presence of a compensatory mechanism associated with cortisol binding which maintains the plasma level of free, biologically active cortisol when hemodilution has reduced the plasma level of total cortisol.
对12例接受心脏直视手术的患者研究了血液稀释对血浆总皮质醇和游离皮质醇水平的影响。在每种情况下，体外循环（ECC）开始时，血细胞比容值迅速降至25%至30%，并在灌注期间维持在该水平附近。随着血液稀释，血浆总皮质醇水平显著下降（p<0.0001），但由于游离形式的血浆皮质醇百分比增加，游离的、具有生物活性的皮质醇的血浆浓度维持在稀释前水平。血液稀释程度与游离皮质醇分数的升高百分比之间存在高度显著的相关性（r = 0.79；p<0.001）。这些结果表明存在一种与皮质醇结合相关的代偿机制，当血液稀释降低了血浆总皮质醇水平时，该机制可维持游离的、具有生物活性的皮质醇的血浆水平。
