Mode of ventilation during cardiopulmonary bypass does not affect immediate postbypass oxygenation in pediatric cardiac patients

Study ObjectiveTo investigate the impact of different modes of ventilation during cardiopulmonary bypass (CPB) on immediate postbypass oxygenation in pediatric cardiac surgery.DesignProspective, randomized clinical trial.SettingUniversity hospital.Patients50 pediatric patients (18 girls, 32 boys), aged 4 months to 15 years, undergoing elective repair of congenital heart disease.InterventionsPatients were randomized to receive one of 5 modes of ventilation during bypass. Groups 1 and 2 received high-frequency/low-volume ventilation with 100% (group 1) or 21% oxygen (group 2). Groups 3 and 4 received continuous positive airway pressure of 5 cm H2O with 100% (group 3) or 21% oxygen (group 4); and in group 5, each patient's airway was disconnected from the ventilator (passive deflation).MeasurementsBlood gas analysis and spirometry data were recorded 5 minutes before chest opening, 5 minutes before inducing bypass, 5 minutes after weaning from bypass, and 5 minutes after chest closure.Main ResultsThere were no differences in Pao2 values among the 5 groups studied and at the different time points. Lung compliance was higher 5 minutes before bypass in group 1 versus group 5 (34 ± 13 mL/cm H2O vs 20 ± 9 mL/cm H2O; P = 0.048).ConclusionsMode of ventilation during CPB did not affect immediate postbypass oxygenation.