title: Improved survival rate by temperature control at compression sites in rat model of crush syndrome.
abstract: BACKGROUND
  Crush syndrome (CS) has been reported in disasters, terrorist incidents, and accidents, and the clinical and pathologic picture has gradually been clarified. Few lethal and reproducible animal models of CS with use of a quantitative load are available. A new model is needed to investigate pathologic and therapeutic aspects of this injury.
  
  
  METHODS
  Using a device built from commercially available components, both hindlimbs of anesthetized rats were respectively compressed for 6 h using 3.6-kg blocks. The effects of trunk warming alone without compressed hindlimbs (Group A), non-warming at room temperature (Group B), whole-body warming including compressed hindlimbs (Group C), or warming of compressed hindlimbs alone (Group D) during compression were examined. Survival rates were compared and hematological and histologic analyses were performed at specific time points after compression release.
  
  
  RESULTS
  Limb or whole-body warming significantly worsened the survival of rats. We found a much lower survival rate of 0%-10% in animals, in which the hindlimbs were warmed during compression (Groups C and D) at 12 h after compression release, compared with 90%-100% in animals without warming of the hindlimbs (Groups A and B). Groups C and D showed significantly enhanced hyperkalemia at ≥4 h after compression release and all blood samples from dead cases showed hyperkalemia (>10 mEq/L).
  
  
  CONCLUSIONS
  We developed a new lethal and reproducible rat CS model with a quantitative load. This study found that warming of compressed limbs worsened the survival rate and significantly enhanced hyperkalemia, apparently leading to cardiac arrest.
authors.affiliation: Department of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Takefumi
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Division of Environmental Medicine, National Defense Medical College Research Institute, National Defense Medical College, Tokorozawa, Saitama, Japan. Electronic address: bxb01424@nifty.com.
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Department of Medical Engineering, National Defense Medical College, Tokorozawa, Saitama, Japan; Division of Biomedical Engineering, National Defense Medical College Research Institute, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishihara
authors.affiliation: Department of Medical Engineering, National Defense Medical College, Tokorozawa, Saitama, Japan; Division of Biomedical Engineering, National Defense Medical College Research Institute, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Miya
authors.initials: M
authors.lastname: Ishihara
authors.affiliation: Department of Pathology and Laboratory Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Ogata
authors.affiliation: Division of Environmental Medicine, National Defense Medical College Research Institute, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Yoritsuna
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Tokorozawa Meisei Hospital, Tokorozawa, Saitama, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Shimizu
authors.affiliation: Department of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Maehara
authors.affiliation: Department of Health Crisis Management, National Institute of Public Health, Wako, Saitama, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kanatani
authors.affiliation: Division of Environmental Medicine, National Defense Medical College Research Institute, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Tachibana
mesh_terms: D000818:Animals; D001831:Body Temperature; D003444:Crush Syndrome / Q000097:blood / Q000209:etiology* / Q000473:pathology; D004195:Disease Models, Animal; D006614:Hindlimb / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology; D011188:Potassium / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D016019:Survival Analysis; D013696:Temperature
chemical_list: D011188:Potassium
keywords: Compression; Crush syndrome; Hyperkalemia; Rat model; Reperfusion injury; Warming