Lung protective ventilation in infants undergoing cardiopulmonary bypass surgery for congenital heart disease: A prospective randomized controlled trial.

Abstract

Lung protective ventilation (LPV) has been applied to surgical adults with normal pulmonary function for optimizing mechanical ventilation and reducing postoperative pulmonary complications. Few studies have reported the use of LPV in infants undergoing cardiac surgery with cardiopulmonary bypass (CPB). To explore safety and effectiveness of LPV in infants undergoing CPB surgery for congenital heart disease (CHD). Included in this study were 77 infants who underwent CPB surgery for CHD from November 2017 to September 2018. They were randomized into the LPV group and conventional ventilation (CV) group. In the LPV group, small-tidal-volume (6-8ml/kg) ventilation, lung recruitment by PEEP increment to the maximum level of 15cm H2 O after CPB, and individualized optimal PEEP titration were applied. In the CV group, traditional tidal volume (10-12ml/kg with zero PEEP) was applied. The primary outcome was the ratio of arterial partial pressure of oxygen to inspiratory oxygen fraction (PaO2 /FiO2 ). The secondary outcomes were respiratory dynamic parameters, hypoxemia, prognostic indexes, and postoperative pulmonary complications. PaO2 /FiO2 in the LPV group (416.86, 95%CI: 381.60-452.12) was significantly higher than that in the CV group (263.37, 95%CI: 227.65-299.09) after intervention (P<.001). There was a significant difference in the trend of change in dynamic compliance, alveolar-arterial oxygen difference, arterial-end-expired carbon dioxide difference, driving pressure, and respiratory index between the two groups at different time points from weaning from CPB to 2hours after operation. There was no significant difference in PaO2 /FiO2 , alveolar-arterial oxygen difference, respiratory index, and dynamic compliance 2hours postoperative and in the incidence of postoperative pulmonary complications, prognostic indexes between the two groups. LPV could be used safely in infants undergoing CPB in that it can improve oxygenation, alveolar aeration, and dynamic compliance, and reduce driving pressure, pulmonary shunting, and dead space. Its effect on oxygenation, pulmonary gas exchange, and pulmonary compliance was relatively short, and had less impact on postoperative pulmonary complications and prognosis.