title: Effect of morphine-induced postconditioning in corrections of tetralogy of fallot.
abstract: BACKGROUND
  Results of previous reports on ischemic postconditioning in animals and humans were very encouraging. Although ischemic postconditioning possessed a wide prospect of clinical application, debates on the precise ischemic postconditioning algorithm to use in clinical settings were ongoing. In this regard, pharmacological strategies were possible alternative methods. Accumulating data demonstrated that pharmacological postconditioning with morphine conferred cardioprotection in animals. This trial aimed to evaluate the effect of morphine-induced postconditioning on protection against myocardial ischemia/reperfusion injury in patients undergoing corrections of Tetralogy of Fallot (TOF).
  
  
  METHODS
  Eight-nine consecutive children scheduled for corrections of TOF were enrolled and randomly assigned to either a postconditioning group (patients received a dose of morphine (0.1 mg/kg) injected via a cardioplegia needle into the aortic root for direct and focused delivery to the heart within 1 minute starting at 3 min before aorta cross-clamp removal, n=44) or a control group (the same protocol was performed as in the postconditioning group except that patients received the same volume of saline instead, n=45). The peri-operative relevant data were investigated and analyzed, and the cardiac troponin I (cTnI) was assayed preoperatively, and then 4 h, 8 h, 12 h, 24 h and 48 h after reperfusion.
  
  
  RESULTS
  Morphine-induced postconditioning reduced postoperative peak cTnI release as compared to the control group (0.57 ± 0.15 versus 0.75 ± 0.20 ng/mL, p<0.0001). Morphine-induced postconditioned patients had lower peak inotropic score (5.7 ± 2.4 versus 8.4 ± 3.6, p<0.0001) and shorter duration of mechanical ventilation as well as ICU stay (20.6 ± 6.8 versus 28.5 ± 8.3 hours, p<0.0001 and 40.4 ± 10.3 versus 57.8 ± 15.2 hours, p<0.0001, respectively), while higher left ventricular ejection fraction as well as cardiac output (0.57±0.15 versus 0.51±0.13, p=0.0467 and 1.39 ± 0.25 versus 1.24 ± 0.21 L/min, p=0.0029, respectively) as compared to the control group during the first postoperative 24 hours.
  
  
  CONCLUSIONS
  Morphine-induced postconditioning may provide enhanced cardioprotection against ischemia/reperfusion injury in children undergoing corrections of TOF.
authors.affiliation: Department of Cardiothoracic Surgery, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai, 1400 Western Beijing Rd, Shanghai 200040, PR China. zhangrf8@hotmail.com
authors.forename: Rufang
authors.initials: R
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Shen
authors.forename: Yewei
authors.initials: Y
authors.lastname: Xie
authors.forename: Lin
authors.initials: L
authors.lastname: Gen
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ji
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D057775:Ischemic Postconditioning / Q000379:methods*; D008297:Male; D009020:Morphine / Q000627:therapeutic use*; D015428:Myocardial Reperfusion Injury / Q000097:blood / Q000188:drug therapy / Q000517:prevention & control*; D020011:Protective Agents / Q000627:therapeutic use; D013771:Tetralogy of Fallot / Q000097:blood / Q000601:surgery*; D016896:Treatment Outcome; D019210:Troponin I / Q000097:blood
chemical_list: D020011:Protective Agents; D019210:Troponin I; D009020:Morphine