Background: The infusion of small volumes of hypertonic saline solution or hypertonic saline plus dextran 70 is remarkably effective in restoring adequate hemodynamic conditions after hypovolemic shock. This prospective double-blind study compares the immediate hemodynamic effects of a bolus infusion of 7.5% NaCl or 7.5% NaCl plus 6% dextran 70 (both 2400 mOsm/L) in severe hypovolemia.
Methods: One hundred five adult patients admitted in hypovolemic shock (systolic blood pressure less than 80 mm Hg) were revived on arrival to the emergency room and administration of a 250 ml intravenous bolus of hypertonic saline solution (n = 35), hypertonic saline plus dextran (n = 35), or isotonic saline solution (n = 35). This infusion was immediately followed by standard crystalloid and blood replacement until systolic pressure reached 100 mm Hg. Mean arterial pressure (MAP) was measured every 5 minutes, and all intravenous infusions were registered. Plasma volume expansion was calculated from plasma protein concentration measurements. Patients were followed up throughout their hospital course, and results of treatment were recorded.
Results: At the end of the infusion period, and 5 and 10 minutes after infusion, MAP was significantly higher in patients receiving either hypertonic solution, compared with the group receiving isotonic solution. All groups showed similar trends toward restoration of hemodynamic parameters thereafter. The calculated plasma volume expansion, immediately after the bolus infusion, was significantly higher (24.1% +/- 1.8% and 24.9% +/- 1.1%) in the hypertonic groups, compared with isotonic groups (7.9% +/- 1.3%). Significantly greater volumes of fluids were required to restore systolic pressure in the patients receiving isotonic saline solution than in the groups receiving hypertonic solution. There were no significant differences between the groups receiving hypertonic solutions. The incidence of complications was low, and the mortality rate was similar in all groups.
Conclusions: Infusion of 250 ml hypertonic saline solution in patients with severe hypovolemia was not related to any complications, nor did it affect mortality rates; it improved MAP significantly, acutely expanded plasma volume by 24%, and reduced significantly the volumes of crystalloids and blood required in their resuscitation.