Smith G J, Kramer G C, Perron P, Nakayama S, Gunther R A, Holcroft J W
J Surg Res. 1985 Dec;39(6):517-28. doi: 10.1016/0022-4804(85)90120-9.
Small volumes (4 ml/kg) of 2400 mOsm NaCl restore cardiac output and mean arterial pressure to 80% of baseline after hemorrhage (65% of blood volume) in unanesthetized sheep. An equal volume of normal saline is less effective. To identify an optimal hypertonic solution, we screened six 2400 mOsm solutions in 18 randomized experiments in 8 sheep: NaCl, NaHCO3, NaCl/sodium acetate, NaCl/mannitol, NaCl/6% Dextran 70, and glucose. Cardiovascular function, as determined by cardiac output and mean arterial pressure, was restored best with NaCl, NaCl/NaAc, and NaCl/Dex. These three solutions were then evaluated using 18 sheep in 36 experiments. Following a 1-hr baseline period, the sheep were bled to a mean arterial pressure of 50 mm Hg for 2 hr. One of the solutions was then given in a volume of 4 ml/kg over 2 min and the sheep were monitored for 3 hr. Within 3 min of the infusion, cardiac output increased to greater than 100% of baseline for all three solutions. The NaCl-Dex solution sustained a significantly higher cardiac output over the 3-hr observation period than the other solutions. Plasma volume increased for all solutions following infusion. NaCl-Dex maintained plasma volume significantly better than the other solutions. As a further control, an isotonic solution of 6% Dextran 70 in normal saline was studied. It was not as effective as the hypertonic NaCl-Dex in maintaining cardiac output, mean arterial pressure, or plasma volume. Osmolality increased 10% (309 to 326 mOsm/kg H2O), plasma [NA] increased 7% (151 to 161 meq/liter), and plasma [K] decreased from 3.9 to 2.6 meq/liter following the hypertonic infusions. The sheep appeared to tolerate these electrolyte changes well. We conclude that a single bolus infusion of 2400 mOsm NaCl with 6% Dextran 70 best resuscitates sheep that have been subjected to a moderate degree of hemorrhagic shock compared to several other solutions. Its beneficial effects are caused in part by a sustained reestablishment of plasma volume. More studies are needed to document the safety of dextran in the clinical setting of hemorrhagic shock. Small volumes of hypertonic solutions may be valuable in the initial fluid resuscitation of patients in hemorrhagic shock.
在未麻醉的绵羊中，出血（失血量为血容量的65%）后输注小剂量（4毫升/千克）2400毫渗量的氯化钠可使心输出量和平均动脉压恢复至基线水平的80%。等体积的生理盐水效果较差。为确定最佳高渗溶液，我们在8只绵羊身上进行了18项随机实验，筛选了六种2400毫渗量的溶液：氯化钠、碳酸氢钠、氯化钠/醋酸钠、氯化钠/甘露醇、氯化钠/6%右旋糖酐70和葡萄糖。通过心输出量和平均动脉压测定的心血管功能，使用氯化钠、氯化钠/醋酸钠和氯化钠/右旋糖酐恢复得最好。然后在36项实验中使用18只绵羊对这三种溶液进行评估。在1小时的基线期后，将绵羊放血至平均动脉压为50毫米汞柱并持续2小时。然后在2分钟内以4毫升/千克的体积给予其中一种溶液，并对绵羊监测3小时。在输注的3分钟内，所有三种溶液的心输出量均增加至基线水平的100%以上。在3小时的观察期内，氯化钠-右旋糖酐溶液的心输出量显著高于其他溶液。输注后所有溶液的血浆容量均增加。氯化钠-右旋糖酐维持血浆容量的效果明显优于其他溶液。作为进一步对照，研究了在生理盐水中的6%右旋糖酐70等渗溶液。在维持心输出量、平均动脉压或血浆容量方面，它不如高渗氯化钠-右旋糖酐有效。高渗输注后，渗透压增加10%（从309毫渗量/千克水增至326毫渗量/千克水），血浆[钠]增加7%（从151毫当量/升增至161毫当量/升），血浆[钾]从3.9毫当量/升降至2.6毫当量/升。绵羊似乎能很好地耐受这些电解质变化。我们得出结论，与其他几种溶液相比，单次推注2400毫渗量的氯化钠与6%右旋糖酐70能使遭受中度失血性休克的绵羊得到最佳复苏。其有益效果部分归因于血浆容量的持续恢复。需要更多研究来证明右旋糖酐在失血性休克临床环境中的安全性。小剂量高渗溶液在失血性休克患者的初始液体复苏中可能具有重要价值。
