[Effects of liquids with different osmotic pressure and different oxygen concentration on resuscitation of hemorrhagic shock at high altitude in rat].
OBJECTIVE
To compare the effects of liquids with different osmotic pressure and different oxygen concentration on resuscitation of hemorrhagic shock at high altitude.


METHODS
Hemorrhagic shock model of Sprague-Dawley (SD) rats was reproduced by Weigger method at the altitude of 3,658 meters. After 1 hour blood loss, the rats were treated either with normal saline, 75 g/L hypertonic saline solution, 60 g/L dextran 40 solution, solution of 75 g/L hypertonic saline solution with 60 g/L dextran 40, or hypertonic sodium chloride hydroxyethyl starch 40 solution, and all the above solutions were oxygenated with oxygen by high pressure. All the solutions were infused via external jugular vein (4 ml/kg) to resuscitate the rats, and the effects of different solutions on blood pressure (BP), blood gas, intraventricular pressure, water contents of lung or brain, survival time and survival rates were observed.


RESULTS
The BP, mean arterial pressure (MAP), partial pressure of oxygen in artery (PaO2), left ventricular systolic pressures (LVSP), maximum upstroke velocity (+dp/dt max) and maximum descending velocity (-dp/dt max) of intraventricular pressure, survival time and survival rate were increased (P<0.05 or P<0.01), but the survival time of the rats in groups treated with hypertonic solutions or hypertonic colloid solutions was obviously prolonged. In particular, survival time and survival rate of the rats in the groups treated with hypertonic colloid solutions were raised more significantly than those of other groups. Besides, the results showed that BP rose steadily in all the groups, PaO2 and LVSP of these groups significantly increased, but partial pressure of carbon dioxide in artery (PaCO2) showed no significant change. Infusion of 4 ml/kg of liquids did not increase water contents of lung or brain. Hyperoxic solutions had no effect on the right ventricular pressure, but the oxygenated liquids could lower the right ventricular pressure at the beginning of resuscitation, suggesting that oxygen transfer through the vein could lower the pulmonary artery pressure and improve the right ventricle function.


CONCLUSIONS
Liquids with different osmotic pressure and at different oxygen concentration showed therapeutical effect on hemorrhagic shock at high altitude in rat, with hypertonic colloid solution being the best among the liquids under examination.
Zhou
Qi-quan
QQ
Department of High Altitude Disease, College of High Altitude Military Medicine, Third Military Medical University, Chongqing 400038, China.
Liu
Fu-yu
FY
Gao
Yu-qi
YQ
He
Yi
Y
Zheng
Bi-hai
BH
Wang
Hong-bin
HB
Li
Su-zhi
SZ
Liu
Liang-ming
LM
D000531:Altitude; D000818:Animals; D003911:Dextrans / Q000008:administration & dosage; D004195:Disease Models, Animal; D005260:Female; D005440:Fluid Therapy / Q000379:methods; D006982:Hypertonic Solutions / Q000008:administration & dosage; D008297:Male; D009997:Osmotic Pressure; D010100:Oxygen / Q000008:administration & dosage; D010952:Plasma Substitutes / Q000008:administration & dosage*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation / Q000379:methods*; D012771:Shock, Hemorrhagic / Q000628:therapy*; D012965:Sodium Chloride / Q000008:administration & dosage
D003911:Dextrans; D006982:Hypertonic Solutions; D010952:Plasma Substitutes; D012965:Sodium Chloride; D010100:Oxygen