title: Comparisons of lactated Ringer's and Hextend resuscitation on hemodynamics and coagulation following femur injury and severe hemorrhage in pigs.
abstract: BACKGROUND
  This study compared coagulation function after resuscitation with Hextend and lactated Ringer's (LR) solution in pigs with tissue injury and hemorrhagic shock.
  
  
  METHODS
  Pigs were randomized into control (n = 7 each), LR, and Hextend groups. Femur fracture was induced using the captive bolt stunner at midshaft of the pigs' left legs, followed by hemorrhage of 60% total blood volume and resuscitation with either Hextend (equal to bled volume) or LR to reach the same mean arterial pressure. Pigs in the control group were not bled or resuscitated. Hemodynamics was monitored hourly for 6 hours. Blood samples were taken at baseline (BL), after hemorrhage, 15 minutes, 3 hours, and 6 hours after resuscitation for blood and coagulation measurements.
  
  
  RESULTS
  Mean arterial pressure decreased to 50% of BL by the 60% hemorrhage but returned to near BL within 1 hour after LR or Hextend resuscitation. Heart rate was increased (from 91 ± 4 beats per minute to 214 ± 20 beats per minute) by hemorrhage and decreased after resuscitation but remained elevated above BL in both groups. Resuscitation with Hextend (42 mL/kg) or LR (118 ± 3 mL/kg) reduced hematocrit, total protein, fibrinogen, and platelet counts, with greater decreases shown in the Hextend group. Clot strength was lower but returned to BL by 3 hours in the LR group, whereas it remained reduced for the 6-hour period after Hextend. The overall clotting capacity after LR was decreased after hemorrhage and resuscitation but returned to BL by 3 hours, whereas it remained low after Hextend for the 6-hour experiment period.
  
  
  CONCLUSIONS
  After traumatic hemorrhage, coagulation function was restored within 6 hours with LR resuscitation but not with Hextend. The lack of recovery after Hextend is likely caused by greater hemodilution and possible effects of starches on coagulation substrates and further documents the need to restrict the use of high-molecular-weight starch in resuscitation fluids for bleeding casualties.
authors: US Army Institute of Surgical Research, Fort Sam Houston, Texas 78234, USA. wenjun.martini@amedd.army.mil
authors: Wenjun Z
authors: WZ
authors: Martini
authors: Michael A
authors: MA
authors: Dubick
authors: Lorne H
authors: LH
authors: Blackbourne
mesh_terms: D000818:Animals; D001777:Blood Coagulation; D004195:Disease Models, Animal; D005269:Femur / Q000293:injuries*; D006439:Hemodynamics; D006470:Hemorrhage / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D007262:Infusions, Intravenous; D007552:Isotonic Solutions / Q000008:administration & dosage*; D012151:Resuscitation / Q000379:methods*; D000077325:Ringer's Lactate; D012720:Severity of Illness Index; D013552:Swine; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000150:complications* / Q000503:physiopathology
chemical_list: D007552:Isotonic Solutions; D000077325:Ringer's Lactate