title: Dried platelets in a swine model of liver injury.
abstract: BACKGROUND
  Lyophilization may facilitate production of a safe, portable, easily storable, and transportable source of platelets for bleeding patients. The objective of this study was to examine the impact of lyophilized human and porcine platelets in a swine liver injury model of nonsurgical hemorrhage.
  
  
  METHODS
  Anesthetized pigs (40 kg) had a controlled 35% total blood volume bleed from the right jugular vein followed by cooling to 35°C and resuscitation with Ringer's lactate to achieve a 3:1 blood withdrawal resuscitation. Through a midline laparotomy, the liver was injured with two standardized 5 × 5-cm grids with lacerations 1 cm apart and 0.5 cm deep. After 2 min of uncontrolled hemorrhage, the animals were treated with placebo (n = 5), lyophilized human (n = 5, HP), or swine platelets (n = 5, SP). At 15 min, shed blood was calculated. The animals then underwent abdominal closure. At 48 h, the animals were killed for histopathologic evaluation of the lung, kidney, and heart.
  
  
  RESULTS
  Intraoperative blood loss at 15 min was significantly higher in the HP arm (SP: 4.9 ± 2.9 mL/kg, HP: 12.3 ± 4.7 mL/kg, and control: 6.1 ± 2.5 mL/kg; P = 0.013). Mortality at 48 h was 20% in all three arms, due to uncontrolled intra-abdominal bleeding. At the time the animals were killed, SP animals had a significantly higher hematocrit (SP: 22.0% ± 3.0%, HP: 15.1% ± 4.9%, and control: 13.9% ± 0.6%; P = 0.026). No significant difference was found in platelet count (SP: 319.3 ± 62.1 × 10(3)/µL, HP:361.5 ± 133.6 × 10(3)/µL, and control: 242.7 ± 42.5 × 10(3)/µL; P = 0.259). Histopathology of kidneys, lungs, and heart demonstrated no evidence of thromboembolic complications.
  
  
  CONCLUSIONS
  In this swine model of liver injury, human lyophilized platelets increased intraoperative blood loss. With the use of species-specific lyophilized platelets, however, this effect was abolished, with a decrease in blood loss at 48 h after injury.
authors.affiliation: *Division of Trauma and Surgical Critical Care, University of Southern California, Los Angeles, California; †Division of Trauma and Surgical Critical Care and ‡Department of Surgery, University of Arizona, Tucson, Arizona; and §Cellphire Inc, Rockville, Maryland.
authors.forename: Kenji
authors.initials: K
authors.lastname: Inaba
authors.forename: Galinos
authors.initials: G
authors.lastname: Barmparas
authors.forename: Peter
authors.initials: P
authors.lastname: Rhee
authors.forename: Bernardino C
authors.initials: BC
authors.lastname: Branco
authors.forename: Michael
authors.initials: M
authors.lastname: Fitzpatrick
authors.forename: Obi T
authors.initials: OT
authors.lastname: Okoye
authors.forename: Demetrios
authors.initials: D
authors.lastname: Demetriades
mesh_terms: D000818:Animals; D001792:Blood Platelets; D005260:Female; D005612:Freeze Drying; D006470:Hemorrhage / Q000628:therapy; D006801:Humans; D008099:Liver / Q000293:injuries*; D013552:Swine