RESUMO
OBJECTIVE: To investigate the effects of hypertonic sodium chloride hydroxyethyl starch 40 (HSH) on brain edema and morphological changes during whole body hyperthermia (WBH) in rats. METHODS: Sixty adult male SD rats were randomized into control group, WBH group without fluid infusion (group HT), WBH group with Ringer's infusion (group RL), WBH group with HAES + Ringer's infusion (group HRL) and WBH group with HSH infusion (group HSH). WBH was induced by exposure to 36 degrees celsius; for 3 h to achieve a rectal temperature of 41-42 degrees celsius;, and the corresponding fluids were administered intravenously within 30 min at the beginning of WBH. The control rats were housed at a controlled room temperature (22∓1) degrees celsius; for 4 h. After cooling at room temperature for 1 h, the rats were sacrificed and brain water content and morphological changes were evaluated. RESULTS: Compared with the control group, all the WBH groups had significantly increased brain water content (P<0.05 or 0.01), but group HSH showed a significantly lower brain water content than group HT (P<0.05). The rats in groups HT, RL and HRL showed serious to moderate structural changes of the brain tissue and nerve cells, but HSH group had only mild pathologies. CONCLUSION: HSH can reduce brain edema and ameliorate the damages to brain cells in rats exposed to WBH.