Background: Herein, we compared the effectiveness of different small volume resuscitation in a rat model of heatstroke.
Methods: Anesthetized rats, immediately after the onset of heatstroke, were randomly divided into 5 groups and given the following: (a) nothing; (b) 0.9% NaCl (1-10 mL/kg of body weight, i.v.); (c) hydroxyethyl starch (HAES) (6%, 1-10 mL/kg of body weight, i.v.); (d) 7.2% NaCl (1-10 mL/kg of body weight, i.v.); and (e) hyper-HAES (6% HAES plus 7.2% NaCl, 1-10 mL/kg of body weight, i.v.).
Results: When the untreated or 0.9% NaCl (1-5 mL/kg of body weight)-treated rats underwent heat stress, their survival time values were found to be 20 to 22 minutes. Resuscitation with 10 mL/kg of body weight of 0.9% NaCl, 6% HAES, 7.2% NaCl, or hyper-HAES, their survival time values, respectively, are 93+/-6, 101+/-12, 154+/-18, or 286+/-21. Apparently, the order of effectiveness in resuscitation of heatstroke is hyper-HAES>7.2% NaCl>0.9% NaCl or 6% HAES. The heatstroke-induced hypotension, cerebral ischemia and hypoxia, hypercoagulable state, activated inflammation, and hepatic and renal dysfunction can be significantly reduced by hyper-HAES.
Conclusions: Our results suggest that hyper-HAES seems superior to 7.2% NaCl or HAES alone in resuscitation of heatstroke. The benefit of hyper-HAES during heatstroke is related to restoration of normal multiorgan function.