Efficacy of Nitric Oxide Administration in Attenuating Ischemia Reperfusion Injury during Neonatal Cardiopulmonary Bypass
Chawki Elzein, MD, Chawki Elzein, Cynthia Urbas, Bonnie Hughes, Yi Li, Cheryl Lefaiver, Michel Ilbawi, Luca Vricella.
Advocate Children's Hospital, Oak Lawn, IL, USA.
Objective: Nitric Oxide (NO) plays several protective roles in ischemia/reperfusion (I/R) injury.We hypothesized that NO administration during cardiopulmonary bypass (CPB) ameliorates the I/R injury and help the postoperative recovery after the Norwood procedure.Methods:Over a 3 years period,24 neonates who underwent a Norwood procedure were enrolled in a prospective randomized blinded controlled trial to receive NO(12 patients) or placebo(12 patients) into the oxygenator of the CPB circuit during the Norwood procedure. Markers of I/R injury were collected at baseline(T0),after weaning from CPB before modified ultrafiltration(T1),after modified ultrafiltration(T2) and at 12 hours(T3) and 24 hours(T4) after surgery,and they were compared between both groups,as well as other postoperative clinical variables.Results:There was no difference in age,weight,anatomical diagnosis, cardiopulmonary bypass and aortic cross clamp time between both groups.Troponin levels were lower in the study group at T1(0.62 vs 0.87 ng/ml, p=0.31) and became significantly lower at T2(0.36 vs 0.97 ng/ml, p=0.009).There were no significant differences between both groups for all other markers,but all markers were significantly higher at the end of CPB(T2) compared to baseline(T0).Despite a lower troponin level,there was no difference in inotropic scores or ventricular function between both groups.Time to start diuresis,time to sternal closure and extubation,and intensive care unit and hospital stay were not different between both groups.There was also no difference in the chest tube drainage and blood transfusions.Conclusion:administration of NO into the oxygenator of CPB during the Norwood procedure has myocardial protective effects, but has no effect on postoperative recovery.Larger sample size may be needed to show clinical differences.