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Use of Hypertonic Fluid Solutions in Hemorrhagic Shock

　　David Hoyt, MD,[20] from the University of California San Diego Medical Center, San Diego, California, discussed the use of hypertonic fluid solutions in hemorrhagic shock. It appears that the average crucial time from injury to death is 6 hours, as seen in various older and more contemporary studies.[21] This time window has a fundamental importance when resuscitation is considered. After traumatic bleed, the arterial blood pressure drops and the amount of bleeding before death is slowed. There are concerns that volume resuscitation might lead to increased bleeding. Hypertonic solutions (HTS) are attractive agents as they provide hemodynamic restoration with less volume. Preparations are 7.5% NaCl, 7.5% plus dextran, and 3% NaCl. Only the 3% solution is approved by the US Food and Drug Administration. In a model of pig iliac artery injury, it was associated with less hematoma, more circulating red blood cells, and better transcapillary filling. This occurs through decreased endothelial swelling and fluid shift induced by hyperosmolarity. HTS also decreases intracranial pressure (ICP) and lung water. HTS also has several immunomodulary effects and causes less rolling and sticking of the polymorphonuclear white cells.
　　In a trial in which HTS was administered to human volunteers, depression of the expression of the CD11b neutrophil receptor was shown, suggesting decreased neutrophil-endothelial cell interactions and damage.[22] In a clinical study by Mattox and associates,[23] HTS was used as prehospital resuscitation for posttraumatic hypotension. Although there were no differences in survival, the HTS-treated patients who required surgery had better survival and fewer complications overall. Another multicenter trial failed to show benefit in survival except for the patients with an admitting Glasgow coma scale (GCS) less than 8.[24] A subsequent meta-analysis suggested an odds ratio of 2.12 favoring survival after HTS.[25] Dr. Hoyt concluded that HTS improves microvascular flow, controls ICP, protects from organ dysfunction, has immunomodulatory effects, and deserves additional multicentered trials to better assess its clinical efficacy.