title: Therapeutic mild hypothermia improves early outcomes in rabbits subjected to traumatic uncontrolled hemorrhagic shock.
abstract: BACKGROUND
  Survival benefits of mild hypothermia in animals suffering from uncontrolled hemorrhagic shock (HS) may be influenced by trauma severity. We hypothesized that mild hypothermia would improve early outcomes based on our rabbit model of severe traumatic HS.
  
  
  METHODS
  Fifty male New Zealand rabbits weighing between 1.6 and 2.2 kg were randomized into one of the five groups: group 1 (sham), group 2 (37°C/80 mm Hg), group 3 (37°C/40 mm Hg), group 4 (34°C/80 mm Hg), and group 5 (34°C/40 mm Hg). Under urethane anesthesia, animals that suffered fractures and uncontrolled HS received prehospital fluid resuscitation (aggressive or limited) with temperature controlled at normothermia or mild hypothermia, hemostasis, and hospital resuscitation followed by observation.
  
  
  RESULTS
  Mild hypothermia significantly improved cardiac systolic function and decreased lung wet-to-dry weight ratios and total injury score compared with normothermia. Group 5 manifested the best results in lung injury. The decreased base excess and pH and increased lactate levels during HS and limited fluid resuscitation were not exacerbated by mild hypothermia. Electrolytes including potassium and calcium and blood glucose levels as well as coagulation were not significantly influenced after mild hypothermia treatment. Seven-hour survival in the hypothermic groups was higher than that in the normothermic groups, although there was no significant difference in survival between groups 5 and 3.
  
  
  CONCLUSIONS
  Therapeutic mild hypothermia improves early outcomes through improving lung and cardiac performance without causing evident homeostasis disturbances in the rabbit model of traumatic uncontrolled HS. Animals may benefit most under the combination treatment with mild hypothermia and limited fluid resuscitation.
authors.affiliation: Department of Emergency Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Shouyin
authors.initials: S
authors.lastname: Jiang
authors.forename: Xiaodi
authors.initials: X
authors.lastname: He
authors.forename: Jian'an
authors.initials: J
authors.lastname: Wang
authors.forename: Guangju
authors.initials: G
authors.lastname: Zhou
authors.forename: Mao
authors.initials: M
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Ba
authors.forename: Jianxin
authors.initials: J
authors.lastname: Yang
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Zhao
mesh_terms: D000818:Animals; D005440:Fluid Therapy; D006863:Hydrogen-Ion Concentration; D007036:Hypothermia, Induced / Q000379:methods*; D007773:Lactates / Q000097:blood; D008168:Lung / Q000473:pathology; D008297:Male; D023421:Models, Animal; D011654:Pulmonary Edema / Q000473:pathology; D011817:Rabbits; D012771:Shock, Hemorrhagic / Q000209:etiology* / Q000401:mortality / Q000628:therapy*; D013599:Systole / Q000502:physiology; D015599:Trauma Severity Indices; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000150:complications*
chemical_list: D007773:Lactates