BRAIN EDEMA AND NEUROLOGICAL STATUS WITH RAPID INFUSION OF LACTATED RINGERS OR 5-PERCENT DEXTROSE SOLUTION FOLLOWING HEAD TRAUMA

Rapid infusion of 0.25 ml/g of 0.98 saline over 30 minutes has been sh own to have no effect on electrolyte balance, neurological severity sc ore (NSS), or brain edema, following closed head trauma (CHT). Rapid i nfusion of the same volume of 5% dextrose solution decreased blood sod ium concentration, increased edema, and decreased NSS following CHT. I n the present study the authors examined the effect of rapid infusion (30 minutes) of smaller volumes of 5% dextrose (0.08 ml/g and 0.16 ml/ g) and of 0.25 ml/g lactated Ringer's solution on blood electrolyte co ncentrations, plasma osmolality, brain edema, and NSS. The purposes of this study were to determine whether rapid infusion of a large volume of lactated Ringer's solution could be given after CHT without increa sing mortality or brain edema or producing electrolyte disturbances, a nd whether small volumes of 5% dextrose could be infused with few or n one of the deleterious effects expected from large volumes of 5% dextr ose. One hundred eighteen mts, which survived halothone anesthesia and CHT, were randomly assigned to one of 15 experimental groups. Fluids were administered beginning 1 hour after scalp incision or CHT. The NS S, extent of edema, blood electrolyte concentrations, and plasma osmol ality in the groups treated with lactated Ringer's solution were not s ignificantly different from those values in the nontreated groups. In addition, the mortality rate after CHT was not increased by administra tion of lactated Ringer's solution. The groups treated with 5% dextros e solution showed a significantly higher mortality rate, but the NSSs of the surviving rats were not different from controls. None of the gr oups treated with 0.16 ml/g 5% dextrose solution survived 24 hours. Al though blood glucose concentration increased to 1126 +/- 102 g% (mean +/- standard deviation) and 1568 +/- 283 g% and blood sodium concentra tion decreased to 110.4 +/- 4.6 mEq/L and 91.0 +/- 5.2 mEq/L in the gr oups treated with 0.08 ml/g and 0.16 ml/g of 5% dextrose solution, res pectively, plasma osmolality was normal and no significant difference could be found between the brain tissue specific gravity of animals in the nontreated and 5% dextrose treatment groups. It is concluded that in the CHT model used in this study, the large volume of lactated Rin ger's solution did not affect blood electrolyte concentration, neurolo gical outcome, or formation of brain edema, whereas smaller volumes of 5% dextrose solution increased blood glucose and decreased blood sodi um concentrations, did not affect plasma osmolality, and had a deleter ious effect on neurological outcome.