Albumin or hetastarch improves neurological outcome and decreases volume of brain tissue necrosis but not brain edema following closed-head trauma inrats

The present study examined whether hemodilution with 20% human serum albumi n (HSA) or 10% hydroxyethyl starch (HES) improved the outcome from closed-h ead trauma (CHT) in rats. Rats anesthetized with halothane were given one o f three hemodilution solutions (i.e., 20% HSA, 10% HES, or control [0.9% sa line]) after CHT or sham surgery. CHT was delivered using a weight drop imp act of 0.5 J onto the closed cranium. The hemodilution solution (volume = 1 % of body weight) was given just after determining the neurological severit y score (NSS) at 1 hour following CHT. The NSS was determined again at 24, 48, and 72 hours following CHT. At 72 hours, brains were removed, and brain edema and brain tissue necrosis volume were determined. Solutions of 20% H SA and 10% HES significantly improved brain tissue necrosis volume (143 +/- 72 mm(3) and 104 +/- 53 mm(3) as compared to 271 +/- 65 mm(3) in controls, mean +/- SD) and NSS (12 +/- 2 and 9 +/- 2 as compared to 15 +/- 2 in cont rols at 72 hours, median +/- range) but not brain edema. The hematocrit dec reased similarly in all groups during hemodilution. Hemodilution with 20% H SA and 10% HES following CHT in rats did not decrease brain edema but did d ecrease brain tissue necrosis volume and NSS (improved neurological functio n), suggesting that the beneficial effect of hemodilution resulted not from decreased edema formation but rather from effects not measured in this stu dy such as improved perfusion of the salvageable brain tissue surrounding t he core injury.