title: Asphyxiation versus ventricular fibrillation cardiac arrest in dogs. Differences in cerebral resuscitation effects--a preliminary study.
abstract: We explored the hypothesis that brain damage after cardiac arrest caused by ventricular fibrillation (VF) needs different therapies than that after asphyxiation, which has been studied less thoroughly. In 67 healthy mongrel dogs of both sexes cardiac arrest (at normothermia) by ventricular fibrillation (no blood flow lasting 10 min) or asphyxiation (no blood flow lasting 7 min) was reversed by normothermic external cardiopulmonary resuscitation, followed by intermittent positive-pressure ventilation for 20 h, and intensive care to 96 h. To ameliorate ischemic brain damage, the calcium entry blocker lidoflazine or a solution of free radical scavengers (mannitol and L-methionine in dextran 40) plus magnesium sulphate, was given intravenously immediately upon restoration of spontaneous circulation. Outcome was evaluated as functional deficit, brain creatine kinase (CK) leakage into the cerebrospinal fluid (CSF) and brain morphologic changes. Lidoflazine seemed to improve cerebral outcome after VF but not after asphyxiation. Free radical scavengers plus magnesium sulphate seemed to improve cerebral outcome after asphyxiation, but not after VF. After VF, scattered ischemic neuronal changes in multiple brain regions dominated, and total brain histopathologic damage scores correlated with final neurologic deficit scores at 96 h (r = 0.66) and with peak CK levels in CSF (r = 0.81). After asphyxiation, in addition to the same ischemic neuronal changes, microinfarcts occurred, and there was no correlation between total brain histopathologic damage scores and neurologic deficit scores or CK levels in CSF.
  
  
  CONCLUSIONS
  Different mechanisms of cardiac arrest, which cause different morphologic patterns of brain damage, may need different cerebral resuscitation treatments.
authors.affiliation: Safar Center for Resuscitation Research (SCRR), Department of Anesthesiology and Critical Care Medicine, University of Pittsburg Medical Center (UPMC), PA 15260, USA.
authors.forename: P
authors.initials: P
authors.lastname: Vaagenes
authors.forename: P
authors.initials: P
authors.lastname: Safar
authors.forename: J
authors.initials: J
authors.lastname: Moossy
authors.forename: G
authors.initials: G
authors.lastname: Rao
authors.forename: W
authors.initials: W
authors.lastname: Diven
authors.forename: C
authors.initials: C
authors.lastname: Ravi
authors.forename: K
authors.initials: K
authors.lastname: Arfors
mesh_terms: D000818:Animals; D001237:Asphyxia / Q000150:complications*; D002545:Brain Ischemia / Q000209:etiology / Q000517:prevention & control*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004285:Dogs; D005260:Female; D016166:Free Radical Scavengers / Q000627:therapeutic use; D006323:Heart Arrest / Q000209:etiology* / Q000628:therapy; D008013:Lidoflazine / Q000627:therapeutic use; D008278:Magnesium Sulfate / Q000627:therapeutic use; D008297:Male; D011175:Positive-Pressure Respiration; D014693:Ventricular Fibrillation / Q000150:complications*
chemical_list: D002121:Calcium Channel Blockers; D016166:Free Radical Scavengers; D008278:Magnesium Sulfate; D008013:Lidoflazine