Brain edema, hemorrhagic necrosis volume, and neurological status with rapid infusion of 0.45% saline or 5% dextrose in 0.9% saline after closed head trauma in rats.

We previously reported that in rats with closed head trauma (CHT), intravenous (IV) administration of 0.25 mL/g of 5% dextrose solution (D5W) increased blood glucose (G), decreased blood sodium (Na), caused no change in blood osmolality (Osm), increased brain edema (BE), and worsened neurological severity score (NSS) and mortality rate (MR). D5W in 0.9% saline (D5NS) is isonatremic and hyperosmolar with respect to blood and may avoid the problems reported with D5W. The present study compared the effects of 0.25 mL/g of D5NS or 0.45% saline (0.45 S) after CHT in rats. In 11 groups of rats, the three experimental variables were CHT (yes or no), IV fluid (none, D5NS, or 0.45 S), and time of death (4 or 24 h). D5NS or 0.45 S was given IV at 1 h after surgical preparation with or without CHT, and experimental values were determined at 1, 2, 4, and 24 h. D5NS decreased BE at 4 h compared with the untreated group, increased Osm (380 +/- 2 mOsm/kg) and G (1278 +/- 199 mg/dL), decreased Na (131 +/- 2 mEq/L) in blood, and caused no significant change in hemorrhagic necrosis volume (HNV), NSS, or MR. 0.45 S increased MR (50%) at 24 h, decreased Osm (270 +/- 5 mOsm/kg) and Na (123 +/- 1 mEq/L) in blood, and caused no significant change in G, BE, HNV, or NSS. We conclude that after CHT in rats, D5NS decreased BE without changing NSS or MR. 0.45 S increased MR and significantly altered blood chemistries.