title: Rapidly induced hypothermia with extracorporeal lung and heart assist (ECLHA) improves the neurological outcome after prolonged cardiac arrest in dogs.
abstract: OBJECTIVE
  We reported previously that therapeutic hypothermia with extracorporeal lung and heart assist (ECLHA) improved neurological outcome after 15 min cardiac arrest (CA) in dogs, although 45 min was needed to achieve hypothermia. We now investigate whether rapidly induced hypothermia with ECLHA (RHE) would result in a better outcome than slowly induced hypothermia with ECLHA (SHE) in dogs.
  
  
  METHODS
  Fifteen mongrel female dogs were divided into two groups: an RHE (n = 7) and an SHE (n = 8) group. Normothermic ventricular fibrillation was induced for 15 min and the animals were resuscitated by ECLHA. Rapid hypothermia was induced with a heat exchanger added to the ECLHA circuit in the RHE group, and by immersing the drainage tube of the ECLHA circuit in an ice water bath in the SHE group. Hypothermia (33 degrees C) was maintained for 20 h. The dogs were weaned from ECLHA at 24 h after resuscitation and treated for 96 h; neurological deficit scores (NDS) were measured throughout this period.
  
  
  RESULTS
  It took 1.6+/-0.8 min to reach 33 degrees C in the RHE group and 49.5+/-12.1 min to reach 33 degrees C in the SHE group. There was no difference in survival rate between the two groups. The NDS at 96 h in the RHE group was better than that in the SHE group (26% (range: 10-28%) versus 32% (26-37%); p < 0.05) although there was no significant difference in NDS between the two groups until 72 h.
  
  
  CONCLUSIONS
  Rapid hypothermic induction might be an important factor to improve neurological outcomes in prolonged CA models.
authors.affiliation: Department of Anesthesiology, Faculty of Medical and Pharmaceutical, Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan. tanny@fc.kuh.kumamoto-u.ac.jp
authors.forename: Hironari
authors.initials: H
authors.lastname: Tanimoto
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ichinose
authors.forename: Taisuke
authors.initials: T
authors.lastname: Okamoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yoshitake
authors.forename: Masafumi
authors.initials: M
authors.lastname: Tashiro
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sakanashi
authors.forename: Hushan
authors.initials: H
authors.lastname: Ao
authors.forename: Hidenori
authors.initials: H
authors.lastname: Terasaki
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D002315:Cardiopulmonary Bypass; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D006323:Heart Arrest / Q000628:therapy*; D006355:Heart-Lung Machine; D007036:Hypothermia, Induced / Q000379:methods*; D015996:Survival Rate; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000150:complications