Effect of seawater immersion on pathophysiological changes in rats combined burns with open abdominal injury

Abstract Objective: To observe the effects of seawater immersion on the pathophysiological changes in rats combined burns with open abdominal injury.Method: Eighty-eight male Sprague-Dawley(SD) rats combined burns with open abdominal injuries were randomly divided into the seawater immersion group (SI) and the control group (Ctl).Rats in SI group were immersed in seawater at 15℃ for 1 hour. The changes of respiration, blood pressure, rectal temperature, blood gases, blood electrolyte, liver and kidney function, coagulation function, heart damage and animal survival at different time points in the early stage (within 9 hours after injury) were observed.Result: After immersed in seawater, the body temperature of rats in SI group were significantly decreased, the respiration were remarkably inhibited and the blood pressure were obviously declined as compared to those in Ctl group. The blood pH of rats in SI group were significantly lower than those in Ctl group, showing severe acidosis(P<0.05). The changes of HCO3-, PCO2 and BE also presented the similiar trends(P<0.05). PO2 and PCO2 in SI group were significantly higher than those in Ctl group (P<0.05). However, the SaO2 in SI group were lower than those in Ctl group (P<0.05). Blood sodium and chlorine in SI group were higher than those in Ctl group, showing severe hypernatremia and hyperchloremia(P<0.05). The concentration of potassium and calcium were not obviously changed. The liver and kidney function parameters(AST,ALT,Urea,Crea) in SI group were lower than those in Ctl group 4 hours after injury(P<0.05), while myocardial damage markers (TNT) in SI group were higher than those in Ctl group. There were no significant differences in coagulation function between the two groups. The survival time of the SI group rats were shorter than those in Ctl group and the mortality was higher than those in Ctl group (66.7% vs 41.7%).Conclusion: Low-temperature seawater immersion might aggravate injury, accelerate animal death, induce hypothermia, respiratory depression, acidosis, hypernatremia and hyperchloremia. Immersing in low temperature seawater for 1 hour can cause myocardial damage, but it has protective effects on the liver and kidney. Therefore, more attentions should be paid to the secondary injury caused by seawater immersion in the emergency treatment of the wounded, such as rapidly rewarming, rectifying the acidosis and maintaining the stability of homeostasis of the wounded, so as to lay the foundation for the further definitive treatments.