title: Phosphodiesterase-5 inhibition improves macrocirculation and microcirculation during cardiopulmonary resuscitation.
abstract: OBJECTIVE
  This study is to clarify whether sildenafil, which is a selective inhibitor of the isoform 5 of the enzyme phosphodiesterase, improves macrocirculation or/and microcirculation during ventricular fibrillation (VF) and cardiopulmonary resuscitation (CPR) so as to improve outcomes of resuscitation.
  
  
  METHODS
  Sixteen female pigs were used. After anesthesia, the abdominal cavity was opened to observe the mesenteric microcirculation. Following the guidelines, we determined microvascular flow index, perfused vessel density and proportion of perfused vessels both for large(diameter >20 μm)and small (diameter <20 μm) microvessels. Sildenafil (0.5 mg/kg) or saline was given at 30 minutes before inducing VF. After 8 min VF, 4 min CPR was started and then defibrillation was attempted.
  
  
  RESULTS
  Compared with saline, sildenafil reduced the shocks and duration of CPR (all P < .05), and improved coronary perfusion pressure (CPP) during CPR and 24-hour survival (all P < .05). Sildenafil significantly improved microcirculatory parameters in large microvessel and decreased the lactic acid level during VF and CPR (all P < .05), but the differences in small microvessel were not significant (all P > .05). Microvascular flow index in both large and small microvessels were closely correlated to each other (r = 0.91, P < .01), and to CPP during CPR ([r = .88, P < .01] and [r = .70, P < .05], respectively).
  
  
  CONCLUSIONS
  Sildenafil increases the success of resuscitation through improving macrocirculation and microcirculation during VF and CPR. There is a close relationship between microvascular flow and CPP during CPR.
authors.affiliation: Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation (NO:BZ0370), Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020 China.
authors.forename: Junyuan
authors.initials: J
authors.lastname: Wu
authors.affiliation: Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation (NO:BZ0370), Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020 China. Electronic address: lcscyyy@163.com.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Li
authors.affiliation: Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation (NO:BZ0370), Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020 China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D016887:Cardiopulmonary Resuscitation; D004554:Electric Countershock; D005260:Female; D008643:Mesentery / Q000098:blood supply; D008833:Microcirculation / Q000187:drug effects; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology*; D000068677:Sildenafil Citrate / Q000494:pharmacology*; D013552:Swine; D014693:Ventricular Fibrillation / Q000188:drug therapy* / Q000503:physiopathology*
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D000068677:Sildenafil Citrate