RESUMO
Objective:To compare the effects of 3 different crystalloid fluids at different osmotic concentrations on blood-brain barrier(BBB) and brain edema in severe hemorrhagic shock rats.Methods: A total of 150 male SD rats were equally randomized into a lactated Ringers(LR) group,a 7.2% hypertonic saline(HS) group and a plasmalyte A(PA) group.LR,PA and HS were administered after an hour of severe hemorrhagic shock induced by drawing out about 40% of total blood and maintaining MAP at 35-45 mmHg.Serum S100B,cerebra1 Evans Blue(EB) and water content were determined before(T_0) and 1 h after bleeding(T_1) and immediately(T_2),1 h(T_3) and 2 h(T_4) after administration.The changes of BBB in the hippocampus CA1 area were observed by electron microscopy.Results: The serum S100B level was obviously higher at T_1,T_2,T_3 and T_4than at T_0 in all groups(P0.05).The cerebra1 water content was significantly increased at T_1,T_2,T_3 and T_4in the LR group,at T_1in the HS and at T_1,T_2 and T_3 in the PA as compared with T_0(P