title: Comparisons of normal saline and lactated Ringer's resuscitation on hemodynamics, metabolic responses, and coagulation in pigs after severe hemorrhagic shock.
abstract: BACKGROUND
  Ongoing improvements in trauma care now recommend earlier use of blood products as part of damage control resuscitation, but generally these products are not available at far forward battlefield locations. For the military, questions continue to arise regarding efficacy of normal saline (NS) vs. lactated Ringer's (LR). Thus, this study compared the effects of LR and NS after severe hemorrhage in pigs.
  
  
  METHODS
  20 anesthetized pigs were randomized into control (n = 6), LR (n = 7), and NS (n = 7) groups. Hemorrhage of 60% estimated total blood volume was induced in LR and NS groups by removing blood from the left femoral artery using a computer-controlled pump. Afterwards, the pigs were resuscitated with either LR at 3 times the bled volume or the volume of NS to reach the same mean arterial pressure (MAP) as in LR group. Hemodynamics were measured hourly and blood samples were taken at baseline (BL), 15 min, 3 h and 6 h after resuscitation to measure changes in coagulation using thrombelastograph®.
  
  
  RESULTS
  MAP was decreased by hemorrhage but returned to BL within 1 h after resuscitation with LR (119 ± 7 ml/kg) or NS (183 ± 9 ml/kg, p < 0.05). Base excess (BE) was decreased by hemorrhage; resuscitation with LR recovered BE but not with NS. Total peripheral resistance was decreased with NS and LR, with a larger drop shown in NS. Serum potassium was increased with NS, but not affected with LR. Coagulation changes were similar between LR and NS.
  
  
  CONCLUSIONS
  NS may be inferior to LR in resuscitation due to its vasodilator effects and the risks of metabolic acidosis and hyperkalemia.
authors: US Army Institute of Surgical Research, JBSA Ft, 3698 Chambers Pass, Sam Houston, TX 78234, USA. wenjun.z.martini.civ@mail.mil.
authors: Wenjun Z
authors: WZ
authors: Martini
authors: Douglas S
authors: DS
authors: Cortez
authors: Michael A
authors: MA
authors: Dubick
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects*; D005440:Fluid Therapy / Q000379:methods; D006439:Hemodynamics / Q000187:drug effects*; D020896:Hypovolemia / Q000188:drug therapy*; D007552:Isotonic Solutions / Q000494:pharmacology* / Q000627:therapeutic use; D008887:Military Medicine; D011897:Random Allocation; D000077325:Ringer's Lactate; D012771:Shock, Hemorrhagic / Q000378:metabolism / Q000503:physiopathology*; D012965:Sodium Chloride / Q000494:pharmacology* / Q000627:therapeutic use; D013552:Swine; D014481:United States
chemical_list: D007552:Isotonic Solutions; D000077325:Ringer's Lactate; D012965:Sodium Chloride