Resuscitation of intraoperative hypovolemia: A comparison of normal saline and hyperosmotic/hyperoncotic solutions in swine

Background and Methods: We compared a hypertonic saline-dextran solution (7.5% NaCl/6% dextran-70) with 0.9% NaCl (normal saline) for treatment of intraoperative hypovolemia. Fourteen anesthetized pigs (mean weight 36.3 ± 2.1 kg) underwent thoracotomy, followed by hemorrhage for 1 hr to reduce mean arterial pressure to 45 mm Hg. A continuous infusion of either solution was then initiated and the flow rate was adjusted to restore and maintain aortic blood flow at baseline levels for 2 hrs. Results: Full resuscitation to initial values of aortic blood flow was achieved with both regimens, but the normal saline group required substantially larger volumes and sodium loads to maintain stable hemodynamic values. Normal saline resuscitation produced increases in right ventricular preload (central venous pressure) and afterload (pulmonary arterial pressure and pulmonary vascular resistance), resulting in increased right ventricular work. Conclusions: Hypertonic saline-dextran solution resuscitation of intraoperative hypovolemia is performed effectively with smaller fluid and sodium loads, and is devoid of the deleterious effects associated with fluid accumulation induced by a conventional isotonic solution regimen.