ABSTRACT
In the military setting, where longer transport times and logistical concerns present more difficult problems than in the civilian setting, there is a need for small-volume resuscitation fluids (1). In the past two decades, the answer to this requirement has been the administration of hypertonic saline (HS) solutions with and without the addition of colloids. In 1999, the Committee on Fluid Resuscitation for Combat Casualties for the U.S. Army recommended the use of HS for the treatment of combat casualties (2). The concept behind this treatment strategy is, however, by no means new. During World War I, physicians fully recognized the importance of intravascular volume replacement in hemorrhage. George Crile, who was working in a field hospital in France in 1917, experimented with the infusion of seawater (with a salinity of approximately 35%) diluted in sterile water to treat a pulseless soldier with a gunshot wound (3). The treatment was successful for this particular soldier, but it was not put into general practice. In 1926, however, Silbert used 5% saline to treat Burger’s disease (4). Moderately hypertonic solutions of 1.5% to 3% have been used to treat patients with burn shock and hypovolemia since the 1970s (5). There was a renewed interest in hypertonic solutions in 1980, when researchers in Sao˜ Paulo, Brazil reported using 2400mOsm HS (7.5%) to treat severe hemorrhagic shock in animals successfully (6,7). Numerous studies over the past two decades have established that HS infusions promote diuresis/natriuresis, augment cardiac output, increase cardiac contractility, and directly vasodilate the peripheral vasculature. Adding a colloid can transiently (depending on the type added) expand and preserve plasma volume (8). Several experimental and clinical studies have investigated the efficacy, dosages, and infusion times of different hyperosmotic solutions-primarily 7.5% HS administered solely or in combination with dextran or hetastarch (9-11). The focus now is on 7.5% HS, 7.5% HS/6% dextran 70 (HSD), and 7.2% or 7.5% HS/6% hetastarch (HHS). Although originally developed for hypovolemic resuscitation in the prehospital setting, these solutions have also been used to treat burns, sepsis, nontraumatic hemorrhages, and vascular and cerebral injuries.
