Creteur J, Sun Q, Abid O, De Backer D, Van Der Linden P, Vincent J L
Department of Intensive Care, Erasme University Hospital, Free University of Brussels, Route de Lennik 808, B-1070 Brussels, Belgium.
J Appl Physiol (1985). 2001 Oct;91(4):1701-7. doi: 10.1152/jappl.2001.91.4.1701.
We studied the effects of normovolemic hemodilution on tissue oxygen extraction capabilities in a canine model of endotoxic shock. Eighteen anesthetized and mechanically ventilated dogs underwent normovolemic hemodilution with 6% hydroxyethyl starch solution to reach hematocrit (Hct) levels around 40, 30, or 20% before the administration of 2 mg/kg of Escherichia coli endotoxin. Cardiac tamponade was then induced by repeated injections of normal saline into the pericardial sac to reduce cardiac output and study whole body oxygen extraction capabilities. Whole body critical oxygen delivery was lower in the Hct 20% and 30% groups (8.4 +/- 0.4 and 10.4 +/- 0.7 ml. kg(-1). min(-1), respectively) than in the Hct 40% group (12.8 +/- 0.8 ml. kg(-1). min(-1)) (both P < 0.005). The whole body critical oxygen extraction ratio was higher in the Hct 30% and 20% groups (49.1 +/- 8.2 and 55.2 +/- 4.6%, respectively) than in the Hct 40% group (37.1 +/- 4.4 %) (both P < 0.05). Liver critical oxygen extraction ratio was also higher in the Hct 30% and 20% groups than in the Hct 40% group. The arterial lactate concentrations and the gradient between ileum mucosal PCO(2) and arterial PCO(2) were lower in the Hct 20% and 30% groups than in the Hct 40% group. We conclude that, during an acute reduction in blood flow during endotoxic shock in dogs, normovolemic hemodilution is associated with improved tissue perfusion and increased oxygen extraction capabilities.
我们在犬内毒素休克模型中研究了等容血液稀释对组织氧摄取能力的影响。18只麻醉并机械通气的犬，在给予2mg/kg大肠杆菌内毒素之前，用6%羟乙基淀粉溶液进行等容血液稀释，使血细胞比容（Hct）水平达到约40%、30%或20%。然后通过向心包腔内反复注射生理盐水诱导心包填塞，以降低心输出量并研究全身氧摄取能力。Hct 20%组和30%组的全身临界氧输送量（分别为8.4±0.4和10.4±0.7ml·kg⁻¹·min⁻¹）低于Hct 40%组（12.8±0.8ml·kg⁻¹·min⁻¹）（均P<0.005）。Hct 30%组和20%组的全身临界氧摄取率（分别为49.1±8.2%和55.2±4.6%）高于Hct 40%组（37.1±4.4%）（均P<0.05）。Hct 30%组和20%组的肝脏临界氧摄取率也高于Hct 40%组。Hct 20%组和30%组的动脉血乳酸浓度以及回肠黏膜PCO₂与动脉血PCO₂之间的差值低于Hct 40%组。我们得出结论，在犬内毒素休克期间急性血流减少时，等容血液稀释与改善组织灌注和增加氧摄取能力有关。
