title: Ischemic postconditioning at the initiation of cardiopulmonary resuscitation facilitates functional cardiac and cerebral recovery after prolonged untreated ventricular fibrillation.
abstract: OBJECTIVE
  Ischemic postconditioning (PC) with "stuttering" reintroduction of blood flow after prolonged ischemia has been shown to offer protection from ischemia reperfusion injury to the myocardium and brain. We hypothesized that four 20-s pauses during the first 3 min of standard CPR would improve post resuscitation cardiac and neurological function, in a porcine model of prolonged untreated cardiac arrest.
  
  
  METHODS
  18 female farm pigs, intubated and isoflurane anesthetized had 15 min of untreated ventricular fibrillation followed by standard CPR (SCPR). Nine animals were randomized to receive PC with four, controlled, 20-s pauses, during the first 3 min of CPR (SCPR+PC). Resuscitated animals had echocardiographic evaluation of their ejection fraction after 1 and 4 h and a blinded neurological assessment with a cerebral performance category (CPC) score assigned at 24 and 48 h. All animals received 12 h of post resuscitation mild therapeutic hypothermia.
  
  
  RESULTS
  SCPR+PC animals had significant improvement in left ventricular ejection fraction at 1 and 4 h compared to SCPR (59±11% vs. 35±7% and 55±8% vs. 31±13% respectively, p<0.01). Neurological function at 24h significantly improved with SCPR+PC compared to SCPR alone (CPC: 2.7±0.4 vs. 3.8±0.4 respectively, p=0.003). Neurological function significantly improved in the SCPR+PC group at 48 h and the mean CPC score of that group decreased from 2.7±0.4 to 1.7±0.4 (p<0.00001).
  
  
  CONCLUSIONS
  Ischemic postconditioning with four 20-s pauses during the first 3 min of SCPR improved post resuscitation cardiac function and facilitated neurological recovery after 15 min of untreated cardiac arrest in pigs.
authors.affiliation: Cardiovascular Division, University of Minnesota, Minneapolis 55455-0341, USA.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Segal
authors.forename: Timothy
authors.initials: T
authors.lastname: Matsuura
authors.forename: Emily
authors.initials: E
authors.lastname: Caldwell
authors.forename: Mohammad
authors.initials: M
authors.lastname: Sarraf
authors.forename: Scott
authors.initials: S
authors.lastname: McKnite
authors.forename: Menekhem
authors.initials: M
authors.lastname: Zviman
authors.forename: Tom P
authors.initials: TP
authors.lastname: Aufderheide
authors.forename: Henry R
authors.initials: HR
authors.lastname: Halperin
authors.forename: Keith G
authors.initials: KG
authors.lastname: Lurie
authors.forename: Demetris
authors.initials: D
authors.lastname: Yannopoulos
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003326:Coronary Circulation; D005260:Female; D006321:Heart / Q000502:physiology*; D057775:Ischemic Postconditioning; D013552:Swine; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000628:therapy*