7.5% saline and 7.5% saline/6% dextran for hypovolemic shock.

Abstract

Conventional resuscitation of traumatic hemorrhagic shock involves the intravenous administration of isotonic (normal saline) or slightly hypotonic (lactated Ringer’s, LR) solution beginning in the prehospital setting. Although not conclusive, prior animal and human studies have suggested that alternative resuscitation with hypertonic saline (7.5%) solutions may reduce mortality in these patients. Hypertonic saline-dextran (HSD) (7.5% saline with 6% dextran-70) has been investigated as an alternative resuscitation fluid in critically injured patients,(1–6) HSD results in an increase in serum osmotic pressure, which leads to the redistribution of fluid from the interstitial to the intravascular space. This redistribution leads to rapid restoration of circulating intravascular volume, with a smaller volume of fluid required compared to isotonic or hypotonic crystalloid solutions and decreased accumulation of extravascular volume. The osmotic effect of HSD has been shown to reduce intracranial pressure in brain-injured patients. Thus, the combination of increased systemic perfusion, which increases cerebral perfusion, and a decrease in the intracranial pressure may minimize the progression of secondary brain injury. In addition, recent studies have demonstrated an impact of hypertonicity on limiting the proinflammatory response of circulating inflammatory cells.(7, 8) Thus, hypertonic solutions may have additional beneficial effects by modulating the excessive immuno-inflammatory response following systemic ischemia/reperfusion injury. Hypertonic resuscitation, therefore, has the potential to impact both early and late mortality following traumatic injury. Dextran was initially added to these solutions in an effort to prolong the circulatory effect of hypertonicity. Subsequent to the early clinical trials, however, several preclinical studies demonstrated the reduction of inflammatory organ injury utilizing hypertonic saline rather than HSD.9–13 Removal of the dextran component may enhance the anti-inflammatory effects of this solution, which could reduce the risk of late complications after injury.