Efficacy of saline solutions of different osmotic pressures for hemorrhagic shock rats exposure to seawater immersion

Abstract

Objective To investigate the effect of saline solutions of different osmotic pressures on the lethal triad, liver and kidney functions, and survival in hemorrhagic shock rats combined with seawater immersion. Methods The rats were immersed in 15 ℃ seawater, and inflicted to establish the model of hemorrhagic shock (40 mmHg for 2 h). After being immersed for 2 h, they were placed into the temperature control box for rewarming and treated with Lactate Ringer's (LR) solutions of different osmotic pressures (containing 0.3%, 0.6%, and 0.9% saline, respectively) for resuscitation. Then their blood samples were collected to measure the pH value and evaluate the coagulation, liver and kidney functions. Meanwhile, the body temperature and blood pressure were recorded, and the survival was observed within 72 h. Results The mean arterial pressure (MAP) was significantly decreased after seawater immersion combined with hemorrhagic shock. All the fluids of different osmotic pressures obviously increased the MAP. The pressure could be maintained at 60~70 mmHg with 0.6% saline solution. Seawater immersion combined with hemorrhagic shock induced the rats to develop lethal triad, with notable decreases in body temperature, pH value, and coagulation dysfunction. While, fluid resuscitation treatment alleviated lethal triad, elevated the body temperature and pH value to different degrees, and improve the coagulation function. The treatment of 0.6% saline solution significantly improved the pH value and fibrinogen level, reduced the prothrombin time (PT), activated partial thromboplastin time (APTT) and international normalized ration (INR), with significant differences when compared with simple LR solution (P < 0.05). The results of organ functions showed that 0.6% saline solution significantly reduced the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine (Crea), which were decreased by 32.5%, 29.9%, 22.5% and 19.6%, respectively when compared with simple LR solution (P < 0.05). What's more, 0.6% saline solution also improved the survival rate and prolonged the survival time, with a 72-hour survival rate of 7/16 and a survival time of 35.4±34.0 h, and the survival rate was only 3/16 and the time was merely 29.4±29.1 h after simple LR solution treatment. Conclusion Appropriate hypo-osmotic fluid resuscitation can attenuate acidosis and coagulation dysfunction, protect organ functions, prolong the survival time, and improve the survival rate after seawater immersion combined with hemorrhagic shock.

Keywords

• saline
• osmotic pressure
• seawater immersion
• hemorrhagic shock
• lethal triad