Bicarbonate Ringer's solution for early resuscitation in hemorrhagic shock rabbits.

Background: Fluid resuscitation is important for correcting hypovolemia. Isotonic crystalloids are the preferred solution for the initial clinical management of patients with multiple traumas. Bicarbonated Ringer's solution (BRS), offering physiological levels of bicarbonate ions and electrolyte ions, can be used for supplementing missing extracellular fluid and correcting metabolic acidosis. We here investigated the effects of BRS on the resuscitation of hemorrhagic shock models and compared the resuscitation performance of three crystalloids, including BRS, acetated Ringer's solution (ARS), and normal saline.

Methods: Thirty adult male New Zealand rabbits were randomly divided into five groups (n=6): a sham operation group (Sham group), an operation without fluid therapy group (Shock group), a BRS group, an ARS group, and a normal saline group (Saline group). The New Zealand rabbits experienced rapid bloodletting to shock status and maintained for 20 minutes except Sham group. The status of shock was maintained in the Shock group. The fluid was infused at a rate of 60 mL/kg per hour for 1.5 hours in three fluid therapy group. Measurement of vital signs, arterial blood gas tests, blood biochemistry, hematoxylin and eosin (HE) staining of lung tissue, TUNEL staining of the liver and kidney tissues, and analysis of intestinal flora were performed.

Results: The reduction in both base excess (BE) and bicarbonate ion (HCO3 - ) caused by acidosis in rabbits with hemorrhagic shock was significantly improved in the BRS group when compared with the Saline group at infusion for 30 minutes (T3) and 30 minutes after infusion (T5) (BRS group vs. Saline group, BE: at T3, -4.83±3.60 vs. -12.50±3.27 mmol/L, P<0.01; at T5, -3.67±4.37 vs. -11.00±2.76 mmol/L, P<0.01; HCO3 - : at T3, 22.15±2.63 vs. 15.42±3.03 mmol/L, P<0.01; at T5, 23.15±2.9 vs. 16.23±3.07 mmol/L, P<0.01). Compared with Shock group, liver cell apoptosis due to hemorrhagic shock was relieved in both the BRS group and ARS group (BRS group vs. Shock group: 19.1±3.3 vs. 28.1±6.1, P<0.05; ARS group vs. Shock group: 19.8±5.4 vs. 28.1±6.1, P<0.05).

Conclusions: During resuscitation of hemorrhagic shock, BRS, a novel perioperative balanced crystalloid, is more effective than normal saline in maintaining acid-base balance and in protecting tissues and organs.