Univariate analyses showed statistical significant difference (p≤0.05) between the two groups PMV and non-PMV relating to age, weight, preoperative cyanosis, SpO2, preoperative PAPs, cardio-thoracic ratio, RACHS-1 classification (risk adjustment in congenital heart surgery), the preoperative use of antibiotics, CPB (cardiopulmonary bypass) duration, aortic cross clamp time, operation time, the use of inotropic support, delayed sternal closure, extubation failure, postoperative lactate level, VIS (vasoactive inotropic score) at 0h, 24h, 48h, 72h postoperatively and ICU stay.