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Objective: To compare the efficacy of hypotensive resuscitation with hypertonic saline dextran 70 (HSD) and lactated Ringer (LR) solutions in a rat model of hemorrhagic shock at a simulated altitude of 4,000 m., Methods: Anesthetized rats were bled to maintain their mean arterial pressure (MAP) at 45 mm Hg for 1 h. The distal quarter of the tail was then amputated to allow free blood loss; rats were simultaneously resuscitated with 4 mL kg HSD (HSD group, n = 10) or 4 mL kg LR (LR group, n = 10), followed by hypotensive resuscitation with LR to maintain MAP at 55 to 60 mm Hg for 1 h. A control group received no resuscitation (n = 10). Afterward, the cut end of the tail was ligated. The MAP, acid-base balance, blood loss, volume of fluid infused, and survival were recorded., Results: Compared with controls, HSD resuscitation improved MAP (without increasing uncontrolled blood loss), increased arterial pH and oxygen saturation (SaO2), decreased arterial lactate concentration at the end of resuscitation, and resulted in higher survival rate (P < 0.05). Hypotensive resuscitation with LR also maintained higher MAP, pH, and SaO2 than the control group, but was associated with increased blood loss and inferior survival (P > 0.05)., Conclusions: For hemorrhagic shock at simulated high altitude, resuscitation of rats with a bolus of HSD was associated with reduced blood loss and serum lactate concentration, and superior SaO2, hemoglobin concentration and survival rate, compared with LR solution.

Background: Hypothermia is common during hemorrhagic shock. To warm the victims or not has been controversial. This study aims to investigate the effect of warming during the initial time of hemorrhage on body temperature, blood pressure, and survival in rat hemorrhagic shock models., Methods: Forty anesthetized rats were divided into control group (n = 20) and warming group (n = 20). The rats of control group were placed on a wooden pad without heating, and the rats of warming group were placed on a heating pad maintained at 37°C ± 0.1°C. Blood withdrawal reached 40% of the total blood volume within 60 minutes. Numbers of survival rats, rectal temperature, and mean arterial pressure (MAP) were recorded when blood loss reached 0 (T0), 20% (T20), 30% (T30), and 40% (T40) of the total blood volume, respectively., Results: Rectal temperature and MAP decrease gradually in both groups during hemorrhage. Warming continuously makes the rectal temperature of the warming group (36.68°C ± 0.63°C) slightly higher than that of the control group (36.17°C ± 0.69°C) at T0. The rectal temperature and MAP of the warming group are higher than that of the control group at T20, T30, and T40 (p < 0.05). Survival rates of the warming group are higher than that of the control group (p < 0.01)., Conclusions: Warming during hemorrhage may prevent exacerbation of hypothermia and hypotension and therefore improve survival.