Reinhart K, Rudolph T, Bredle D L, Cain S M
Department of Physiology and Biophysics, University of Alabama, Birmingham 35294.
Am J Physiol. 1989 Jul;257(1 Pt 2):H238-43. doi: 10.1152/ajpheart.1989.257.1.H238.
Hemodynamic and metabolic variables were measured for the whole body and isolated hindlimb of anesthetized dogs during resuscitation from hemorrhagic shock, using a small volume of hypertonic saline or a larger volume of hydroxyethylstarch. Twelve dogs were bled and maintained at a mean arterial pressure (MAP) of 40 mmHg for 30 min. Six dogs were then infused with 7.5% NaCl in 5 ml/kg hydroxyethylstarch (HTS group), and six received 6% hydroxyethylstarch alone (HES group) in an amount to approximate the maximum MAP achieved with hypertonic saline. Hypertonic saline replacement was approximately 16% of shed blood volume compared with 66% for hydroxyethylstarch. With hypertonic saline, cardiac output returned to base line, but O2 delivery did not. Hydroxyethylstarch increased cardiac output above base line, and O2 delivery was near base line. O2 uptake with hydroxyethylstarch peaked at 40% above control at 10 min of resuscitation. Excess O2 uptake in recovery was higher than O2 deficit in hemorrhage with the HES group but not with the HTS group. In the isolated hindlimb, vascular resistance decreased rapidly on hypertonic saline infusion but reached similar levels at 10 min of resuscitation with both fluids. With progressive lowering of blood flow to the pump-perfused hindlimb, ability of limb muscle to extract O2 was the same for the HTS and HES groups. With hemodilution by volume replacement with acellular fluid after hemorrhage, a seemingly adequate cardiac output and arterial pressure may be underresuscitation if O2 delivery does not meet the increased O2 demand.
在失血性休克复苏过程中，使用少量高渗盐水或大量羟乙基淀粉，对麻醉犬的全身和离体后肢的血流动力学和代谢变量进行了测量。12只犬放血并维持平均动脉压（MAP）为40 mmHg 30分钟。然后，6只犬输注7.5%氯化钠与5 ml/kg羟乙基淀粉混合液（HTS组），6只犬单独接受6%羟乙基淀粉（HES组），输注量近似高渗盐水所能达到的最大MAP。高渗盐水补充量约为失血量的16%，而羟乙基淀粉为66%。使用高渗盐水时，心输出量恢复至基线，但氧输送未恢复。羟乙基淀粉使心输出量高于基线，且氧输送接近基线。复苏10分钟时，羟乙基淀粉组的氧摄取量比对照组峰值高40%。HES组复苏时的过量氧摄取高于出血时的氧亏空，但HTS组并非如此。在离体后肢中，输注高渗盐水后血管阻力迅速下降，但两种液体复苏10分钟时达到相似水平。随着泵灌注后肢血流逐渐降低，HTS组和HES组肢体肌肉摄取氧的能力相同。出血后用无细胞液体进行容量置换导致血液稀释，如果氧输送不能满足增加的氧需求，看似足够的心输出量和动脉压可能复苏不足。
