OBJECTIVETo investigate the effects of hypertonic sodium chloride hydroxyethyl starch 40 (HSH) on brain edema and morphological changes during whole body hyperthermia (WBH) in rats.

METHODSSixty 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.

RESULTSCompared 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.

CONCLUSIONHSH can reduce brain edema and ameliorate the damages to brain cells in rats exposed to WBH.