Hypertonic saline/dextran improves renal function after hemorrhage in conscious swine

This study was performed to determine whether resuscitation with a single bolus of 7.5% NaCl/6% Dextran 70 (hypertonic saline/Dextran, HSD) could restore renal function following hemorrhage. Chronically instrumented, conscious pigs were hemorrhaged 28 ml/kg. This level of hemorrhage reduced mean arterial pressure (MAP) and cardiac output (CO) to nearly half, renal blood flow (RBF) to approximately 25%, and glomerular filtration rate (GFR) and urine flow (V) to less than 10% of their initial values. A single, 4 ml/kg bolus injection of HSD increased MAP and RBF to approximately 80% of baseline values and restored CO and GFR to levels which were significantly different from control values. These improvements were sustained for 2 h with no further treatment. Urine flow transiently increased although not to pre-hemorrhage values, and then subsided. Plasma osmolality increased from 275 to 282 mOsm/kg H2O, and plasma sodium increased from 141 to 149 mEq/l. Recovery following administration of an equal volume of normal saline was significantly less for all variables. Euvolemic animals showed no response in MAP, CO, RBF, or GFR when treated with HSD although V, osmotic and sodium excretion increased. These results demonstrate that resuscitation with HSD following hemorrhage not only restores MAP and CO, but maintains renal function as well.