Lactated Ringer’s is Superior to Normal Saline in the Resuscitation of Uncontrolled Hemorrhagic Shock

1. Lactated Ringer’s is Superior to Normal Saline in the Resuscitation of Uncontrolled Hemorrhagic Shock Presented by intern 陳姝蓉 S. Rob Todd, MD et al, Journal of TRAUMA Injury, Infection, and Critical Care, March 2007

2. Introduction • Treatment of hemorrhage: hemostasis & volume resuscitation • Normal saline(NS) & lactated Ringer’s solution(LR): often used for resuscitation of hemorrhagic shock • Purpose: analyze effects of NS and LR on the resuscitation of uncontrolled hemorrhagic shock in a swine model • Hypothesis: similar effects between NS & LR

3. Materials and Methods • Prospective, randomized controlled trial • N = 20 (Yorksire crossbred pigs) underwent invasive line placement, midline celiotomy, and splenectomy • Splenectomy: prevent variation in amounts of sequestered blood • Grade V liver injury (central hepatic v.) created 15 min after stabilization • Resuscitation delayed for 30 minutes to allow the animals to reach their nadir blood pressure • Blindly randomized swine to receive NS or LR resuscitation at 165 mL/min to achieve and maintain baseline MAP for 90 min postinjury • Post 2-hour study period blood analysis: lactate level, ABG, chemistry panel, CBC, PT/PTT, fibrinogen, D-dimer

4. Results

5. NS vs. LR (p=0.02) (p=0.04) (p=0.54) (p=0.34)

6. Mean Arterial pressure (MAP) MAP: No significant differences between the curves (p=0.87)

7. Lab data Significant hypernatremia and hypercholremia in NS group Persistent hyperchloremia metabolic acidosis in NS group Dilutional coagulopathy in NS group

8. Discussion • Plasma chloride concentration was significantly greater in the NS group  persistent acidosis • Adverse effects of acidosis: • Myocardial contractility (↓), peripheral vascular resistance(↓) , inotropic response to catecholamines (↓) • Arrhythmias, platelet dysfunction, and overall coagulation cascade dysfunction • Swafford et al.: LR might prolong lactic acid load caused by hemorrhage in intoxicated individuals • White et al.: • Lactate metabolized by gluconeogenesis (30%) or oxidation(70%)  OH- excess  pH(↑) • Hypothesis: increased volume requirement in NS group was the result of the significant diuresis

9. Discussion • Dilutional coagulopathy • Dependent on type and volume of fluid utilized • In NS animals: fibrinogen (↓), lower platelet count, prolonged PT • Hypothermia : • Slowing enzymatic reactions of coagulation cascade & altering platelet function • Our model: prevented by active warming technique • LR resuscitation: serum lactate (↑) without an associated acidosis

10. Summary • NS resuscitation: • Requires greater volume & increased urine output • Hyperchloremic metabolic acidosis & coagulopathy • LR is superior to NS for the resuscitation of uncontrolled hemorrhagic shock in swine

11. Thanks for your attention!!!