Hypertonic sodium chloride and hemorrhagic shock

Numerous experimental studies on the effects of hypertonic saline in haemorrhagic shock have been published and controlled clinical studies are now beginning to be reported. Animals suffering from an otherwise lethal haemorrhagic shock survived when given hypertonic sodium chloride solution (7.5%, 2,400 mosmol.1-1). In most studies, this solution was more efficient than isotonic fluids in treating controlled haemorrhage. Although the mechanisms involved are not yet fully understood, they certainly include the following: 1) plasma volume expansion due to osmotic fluid shifts into the vascular compartment from intra- and extra-cellular fluid reservoirs, as hypertonic saline induces hypernatraemia and hyperosmolarity, both effects linked to the sodium load; 2) non specific precapillary vasodilation of renal, coronary and splanchnic vessels; 3) arterial and venous vasoconstriction in muscle and skin, due to a vagal reflex set off by the lung osmoreceptors, the efferent pathway of which is likely to be the sympathetic nervous system; 4) increased myocardial contractility. Hypertonic saline also decreases intracranial pressure, and improves lung function during resuscitation of haemorrhagic shock. However, hypertonic saline should not yet be used routinely in man, except in controlled clinical studies. Indeed, there are as yet not enough data concerning humans. Moreover, during uncontrolled haemorrhage, hypertonic saline increased blood pressure, and therefore bleeding, thus reducing survival rates. Further clinical studies are required before hypertonic saline could be safely recommended for treatment of haemorrhagic shock.     

高渗氯化钠羟乙基淀粉40注射液对失血性休克大鼠凝血功能的影响

目的 观察高渗氯化钠羟乙基淀粉40注射液(高渗晶胶液)对失血性休克大鼠复苏过程中凝血功能的影响.方法 16只SD大鼠随机均分为高渗晶胶液复苏组(H组)和复方乳酸钠复苏组(L组),将16只SD大鼠制成失血性休克模型后,分别使用高渗晶胶液和复方乳酸钠各6 ml/kg进行复苏,在休克前(T1)、休克后60 min(复苏前,T2)及复苏后5 min(T3)、30 min(T4)、60 min(T5)时记录血压,取血浆分别测定出血时间(BT)、凝血时间(TT)、凝血酶原时间(PT)、白陶土部分凝血活酶时间(KPTT)和纤维蛋白原(Fib).结果 两组在T2～T5时BT、TT、PT、KPTT均明显长于T1时(P<0.05),Fib明显低于T1时(P<0.05);H组在T3～T5时BT、TT、PT、KPTT均明显短于L组(P<0.05);两组之间Fib在各时点差异无统计学意义.结论 高渗晶胶液对失血性休克凝血功能有影响,使BT、TT、PT、KPTT延长,Fib降低,但尚未超过机体的代偿范围.应用高渗晶胶液进行液体复苏时应在临床推荐剂量内,同时加强凝血功能的监测和控制.     

Hemodynamic improvement in hemorrhagic shock by aortic balloon occlusion and hypertonic saline solutions

The initial treatment of uncontrolled hemorrhagic shock from an abdominal source is controversial. The hemodynamic effects of transfemoral diaphragmatic aortic occlusion with a balloon followed by a single bolus of hypertonic saline solutions have been evaluated in 28 dogs. The animals were submitted to pressure-driven hemorrhage for 90 min, according to mean arterial pressure in the abdominal aorta and randomized into four groups, according to the treatment employed at 34 min after hemorrhage. Group 1 dogs (controls) received isotonic NaCl (0.9%, 308 mOsm/l, 4 ml/kg) without aortic occlusion; group 2 underwent aortic occlusion and received isotonic NaCl (0.9%, 308mOsm/l, 4 ml/kg); group 3 were occluded and received hypertonic NaCl (7.5%, 2400mOsm/l, 4 ml/kg); group 4 were occluded and received hypertonic sodium acetate (10.5%, 2400mOsm/l, 4 ml/kg). There were no significant differences between groups at basal measures and also after 30 min of continuous bleeding, when animals presented with severe shock, and significant decreases in mean arterial pressure, cardiac index, systolic index and cardiac filling pressures; the systemic vascular resistance index was increased. Control animals remained in severe shock throughout the experiment and three died. The recovery of mean arterial pressure in aortic-occluded dogs given isotonic NaCl was associated with a marked increase in systemic vascular resistance index, without improvements in cardiac index, systolic index and cardiac filling pressures. In occluded dogs given hypertonic NaCl and NaAc the mean arterial pressure recovery lasted longer, with lower increases in systemic vascular resistance index, while the cardiac index, systolic index and cardiac filling pressures showed a marked albeit transient increase. Injection of hypertonic saline following aortic occlusion produced significantly better hemodynamic profiles and should be seriously considered for the first treatment in severe uncontrolled hemorrhagic shock from an abdominal vascular source.     

Effect of DHEA on the hemodynamic response to resuscitation in a porcine model of hemorrhagic shock

BACKGROUND: Hemorrhagic shock is a major cause of death from trauma. Pharmacologic treatment has not been satisfactory. The objective of this study was to use a porcine model of hemorrhagic shock and resuscitation to access the hemodynamic effects of dehydroepiandrosterone (DHEA), an adrenal steroid hormone reported to improve cardiac function in patients. METHODS: Hemorrhagic shock was produced in 20- to 30-kg male Yorkshire pigs anesthetized with 2% isoflurane by withdrawing blood through a carotid cannula to a mean arterial pressure (MAP) of 40 to 45 mm Hg and maintaining that level for 60 minutes by further removals of blood. Resuscitation was with 21 mL/kg Ringer's lactate (LR), with (n = 6) or without (n = 6) DHEA (4 mg/kg) dissolved in propylene glycol. The animals were killed after 7 days. Continuous cardiac output (CCO) was recorded using a modified Swan-Ganz catheter system. MAP, heart rate (HR), central venous pressure (CVP), and pulmonary arterial pressure (PAP) were measured every 5 minutes until 60 minutes postresuscitation. From MAP, CCO, HR, and CVP, we calculated total peripheral resistance (TPR), stroke volume (SV), and left ventricular stroke work (SW). RESULTS: The MAP, CCO, SV, and SW decreased significantly during hemorrhagic shock, and then gradually increased to baseline levels during and 1 hour after resuscitation. The TPR was increased during hemorrhagic shock, and then gradually decreased to baseline levels during and after resuscitation. DHEA administration was associated with no significant improvement. CONCLUSION: DHEA when added to standard fluid resuscitation showed no added benefit as resumed by the hemodynamic response.     

高渗氯化钠羟乙基淀粉溶液对失血性休克兔应激反应的影响

目的国观察高渗氯化钠羟乙基淀粉溶液(HHS)对失血性休克兔应激反应的影响。方法 14只兔随机分为HHS组和乳酸盐林格液组(LBS组),每组7只。采用Wiggers改良法制作失血性休克模型,休克后45 min后分别用6 ml／kg的HHS和LRS复苏。在休克前、复苏前、复苏后30、60和120min时取血标本,测定血浆肾上腺素、胰高血糖素、胰岛素及血糖的浓度,计算胰岛素敏感指数(ISI)。结果 与休克前比较,复苏前两组动物血浆肾上腺素、胰高血糖素和血糖浓度均升高,胰岛素浓度均降低(P<0.01);复苏后,HHS组动物血浆肾上腺素、胰高血糖素水平回落,胰岛素浓度升高(P<0.05或0.01),LRS组动物血浆肾上腺素、胰岛素和血糖浓度均升高(P<0.01);HHS组复苏后各时点血浆肾上腺素、复苏后120 min时胰高血糖素、复苏后60 min时胰岛素浓度、复苏后60及120 min时血糖浓度均较低于LRS组(P<0.05或0.01)。复苏期间,两组动物胰岛素敏感指数均较休克前降低(P<0.05或0.01),但HHS组在复苏120 min时恢复至休克前水平(P>0.05)。HHS组于复苏后60、120 min ISI均高于LRS组(P<0.05或0.01)。结论 HHS复苏能够降低失血性休克应激激素水平,阻止胰岛素敏感性下降。     

高渗氯化钠羟乙基淀粉40注射液对外伤性颅内血肿伴失血性休克患者术中颅内压的影响

目的 探讨高渗氯化钠羟乙基淀粉40注射液(HH40)对外伤性颅内血肿伴失血性休克患者术中颅内压(ICP)的影响.方法 外伤性颅内血肿伴失血性休克患者40例,急诊行颅内血肿清除术,随机均分为HH40组(H组)和4.2%高渗盐水组(C组).麻醉诱导后,分别在15 min内快速静脉输入HH40 5ml/kg或4.2%高渗盐水5 ml/kg.在输注HH40或4.2%高渗盐水前即刻(T0)、输注后15 min(T1)、30 min(T2)、60 min(T3)、90 min(T4)、120 min(T5)记录MAP、HR、CVP、尿量,采集桡动脉血测定血浆Na+、K+浓度进行血气分析,并计算各时点脑灌注压(CPP):CPP=MAP-ICP.结果 与T0时比较,T1～T5时两组MAP、CVP、CPP升高,HR减慢,T2～T5时ICP降低(P＜0.05).与C组比较,T4、T5时H组HR减慢和T5时MAP升高(P＜0.05);H组降低ICP幅度与其相似,而降ICP作用维持时间较长(P＜0.05).结论 HH40可安全地用于外伤性颅内血肿伴失血性休克手术患者,能有效地纠正其休克,降低其ICP.     

小容量高渗氯化钠-醋酸钠溶液对失血性休克大鼠的治疗作用

目的观察小容量高渗氯化钠-醋酸钠溶液(HSA)对失血性休克大鼠的治疗作用。方法Wistar大鼠随机分成0.9%NaCl(NS)、7.5%NaCl(HS)、5.0%NaCl-3.5%NaAc(HSA)3组。放血于10min内使平均动脉压降至5.3kPa(1kPa=7.5mmHg)，维持90min。随后分别按4ml/kg体重静脉注入NS、HS、HSA，5min内输完。测定休克前、后及给液后心肌收缩性能、动脉血气，并观察存活率。结果与NS组比较，HSA和HS均能显著升高平均动脉压［90min时，平均动脉压NS(3.20±2.93)kPa，HSA(7.20±3.99)kPa(P<0.05),HS(7.69±3.42)kPa(P<0.01)］，改善心肌收缩性能［90min时，LVSPNS(5.33±4.78)kPa,HSA(10.99±6.65)kPa(P<0.05),HS(11.58±6.18)kPa(P<0.05)］。与NS组比较，HSA显著减轻代谢性酸中毒［90min时,pH值NS7.296±0.048，HSA7.159±0.153(P<0.05)］，提高24h存活率(NS18.2%,HAS75.0%,P<0.05)，主要指标优于HS组。结论HSA是一种较HS治疗失血性休克更为有效的复苏溶液。     

Myocardial utilization of hypertonic glucose during hemorrhagic shock.

Awake pigs were rapidly bled 40% of total blood volume to induce hemorrhagic shock. Immediately after the induction of shock, all pigs received a single intravenous injection of radioactive-labeled glucose-U-14C. Simultaneously with glucose-U-14C injection, ten pigs received single central intravenous injections of unlabeled 50% glucose, four pigs received equiosmolar 25% mannitol, six did not receive either 50% glucose or mannitol, and two received 50% glucose plus insulin. Mean arterial pressure with 50% glucose was 89.9 mm. Hg at 15 minutes of shock and significantly higher than without 50% glucose, 48.3 mm. Hg or after mannitol, 46.7 mm. Hg (P = 0.05). Mean cardiac output at 10 minutes of shock with 50% glucose was 2.24 L. per minute and significantly higher than with mannitol, 1.34 L. per minute, or without 50% glucose, 0.94 L. per minute (P = 0.05.). Evidence for increased anaerobic myocardial utilization of the administered unlabeled 50% glucose was shown by a 12% greater production of unlabeled lactate in the venous coronary sinus blood from unlabeled 50% glucose in contrast to those not given 50% glucose at 10 minutes after shock (P = 0.05). Also, 50% glucose significantly increased mean arterial pressure, cardiac output, and survival over both control groups.     

The influence of diet on response to hemorrhagic shock.

Prior nutrition is known to influence tolerance to hypovolemic shock. This study was undertaken to determine the influence of dietary composition on the response of animals subjected to hypovolemic shock. Particular attention was directed to the role of high and low protein diet content with a proportionate change in carbohydrate content to yield isocaloric diets. Rats were placed on one of three diets and were subsequently subjected to shock either by 1) hemorrhage to a pre-determined mean arterial blood pressure, or by 2) hemorrhage of a pre-determined volume of blood based on per cent of body weight. Serial measurements were made of blood pressure, blood volume removed, survival time,hematocrit, blood glucose, pH and blood gases. The results indicate that a high protein diet does not prolong tolerance to recurrent blood loss but there is a greatly reduced tolerance to hemorrhage shock in rats whose body weight was maintained on a low protein/high carbohydrate diet. The latter animals also exhibited impaired refill of plasma volume and a paradoxical, continuing hyperglycemic response during hypovolemia. This study suggests that although an abundant supply of blood glucose is available as an energy source, glucose uptake in the peripheral tissues is inhibited during hypovolemia by unknown mechanisms and thus homeostasis is curtailed. The protein content of the diet may be a critical factor in carbohydrate use during shock.     

高渗氯化钠-羟乙基淀粉用于前列腺电切术的可行性

目的:研究前列腺肥大的患者在腰硬联合麻醉下行前列腺电切术时输注高渗氯化钠-羟乙基淀粉(hypertonic sodium chloride hetastarch,HSH)预防经尿道电切综合征的作用.方法:随机将60例前列腺肥大患者分为A组(观察组)和B组(对照组)各30例.观察组术前先输注复方氯化钠,手术开始后输注HS...     

The effect of hypertonic saline resuscitation on bacterial translocation after hemorrhagic shock in rats

Translocation of enteric bacteria occurs in rats after hemorrhagic shock. A proposed mechanism involves intestinal mucosal injury by hypoperfusion. Recent work suggests that moderate hypovolemia causes gut arteriolar constriction, which is ameliorated by hypertonic saline resuscitation. Bacterial translocation should, therefore, be reduced when hypertonic saline (HS) is used as the resuscitative fluid. Seventy-eight Sprague-Dawley rats were anesthetized and subjected to 30 minutes of hemorrhagic shock (systolic blood pressure 30 to 50 mm Hg) through a modified Wigger's model. Resuscitation was performed with either shed blood (B), 3% HS + 1/2B (1:1), or with 7.5% HS + 1/2B (1:1). Spleen, liver, and mesenteric lymph nodes were sent for quantitative culture 24 hours later. Translocation occurred if enteric organisms were cultured from at least one organ. Statistical analysis used the Fisher exact test. Compared to autotransfusion, hemodilutional resuscitation from hemorrhagic shock with hypertonic saline resulted in a significant reduction in bacterial translocation (p values were 0.03 and 0.04 for 3% and 7.5% hypertonic saline, respectively). The reduction in translocation after hypertonic saline resuscitation may be the consequence of microcirculatory alterations preventing gut hypoperfusion.     

A comparison of hypertonic to isotonic fluid in the resuscitation of brain injury and hemorrhagic shock

We studied the early and late effects of hypertonic resuscitation (HR) on the injured brain using a porcine model of hemorrhagic shock and focal cryogenic brain injury. After shock, swine were randomly assigned to receive a bolus (4 cc/kg) of either Ringers lactate (RL) or 7.5% hypertonic saline in 6% Dextran 70, followed by either RL or hypertonic sodium lactate to restore mean arterial pressure to baseline. All animals were studied for 24 hr after the start of resuscitation. Bolus HR improved cerebral blood flow (CBF) with a lower intracranial pressure (ICP) than RL. Continued hypertonic resuscitation prolonged the period of improved CBF and low ICP. At 24 hr CBF had deteriorated in the region of injury in all study groups and in the uninjured hemisphere in swine receiving RL. These data suggest that rapid resuscitation without increasing ICP for up to 6 hr as seen with hypertonic fluid could conceivably allow adequate time for surgical evacuation of mass lesions and effectively prevent secondary brain injury. This work underscores the importance of prolonged periods of study when evaluating brain resuscitation from traumatic shock.     

高渗复合液治疗失血性休克的机制研究

目的　研究高渗复合液的脱水作用治疗失血性休克的机制。方法　利用大鼠Wigger′s失血性休克模型 ,通过对比不同复苏液对大鼠下肢腓肠肌水含量的影响来评价高渗复合液的作用效果。结果　在出血性休克并复苏后 ,高渗复合液组的组织水含量 (73 0 %± 1 5 % )较平衡液组(74 8%± 2 0 % )及对照组 (75 4 %± 1 6 % )少 ,差异有显著意义 (P <0 0 5 )。结论　高渗复合液无论在休克状态与水肿状态均可以将细胞和间隙内的水分抽取至血管内 ,从而扩大血容量。