The characterization of postoperative mechanical respiratory requirement in infants and neonates undergoing cardiac surgery on cardiopulmonary bypass in a single tertiary institution

Abstract Objectives : Although neonates and infants undergoing cardiac surgery on cardiopulmonary bypass (CPB) are at high risk of developing perioperative morbidity and mortality including lung injury, the intraoperative profile of lung injury in this cohort is not well described. Given that the postoperative course of patients in the pediatric cardiac surgical arena has become increasingly expedited, the objective of this study was to characterize the profiles of postoperative mechanical ventilatory support in neonates and infants undergoing cardiac surgery on CPB and to examine the characteristics of lung mechanics and lung injury in this patient population that is potentially amendable to early postoperative recovery in a single tertiary pediatric institution. Design : Retrospective data analysis of neonates and infants who underwent cardiac surg on cardiopulmonary bypass. Setting : Single-center, university teaching hospital Participants : The study included 328 neonates and infants who underwent cardiac surgery on cardiopulmonary bypass. We specifically studied a subset of 128 patients: 58 patients undergoing ventricular septal defect (VSD) repair, 36 patients undergoing complete atrioventricular canal (CAVC) repair and 34 patients undergoing bidirectional Glenn (BDG) shunt surgery. Measurements and Main Results : 3.7% of our entire cohort experienced in-hospital mortality. Among all surgical procedures, VSD repair (17.7%) was the most common, followed by CAVC repair (11.0%) and BDG shunt surgery (10.4%). 65.5%, 41.7% and 67.6% of patients who underwent VSD repair, CAVC repair and BDG shunt surgery, respectively, were off mechanical ventilatory support within 24 hours postoperatively. In all the three surgery repairs, lung compliance decreased following CPB compared to pre-CPB phase. 60.3% of patients with VSD repair and 77.8% of patients with CAVC repair showed a PaO2/FiO2 (P/F) ratio of 24 hours) postoperative mechanical ventilatory support. Higher volume of transfused platelets was also associated with postoperative ventilatory support ≥ 24 hours in patients undergoing VSD repair, CAVC repair, and BDG shunt surgery. Conclusion : There was a high incidence of lung injury following CPB in neonates and infants even in surgeries amendable for early recovery. Given that CPB related factors (CPB duration, cross-clamp time) and volume of transfused platelet were significantly associated with prolonged postoperative ventilatory support, the underlying cause of cardiac surgery-related lung injury can be multi-factorial.