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

Abstract

Study Objective To investigate the impact of different modes of ventilation during cardiopulmonary bypass (CPB) on immediate postbypass oxygenation in pediatric cardiac surgery. Design Prospective, randomized clinical trial. Setting University hospital. Patients 50 pediatric patients (18 girls, 32 boys), aged 4 months to 15 years, undergoing elective repair of congenital heart disease. Interventions Patients 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 H 2O with 100% (group 3) or 21% oxygen (group 4); and in group 5, each patient's airway was disconnected from the ventilator (passive deflation). Measurements Blood 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 Results There were no differences in Pa o 2 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 H 2O vs 20 ± 9 mL/cm H 2O; P = 0.048). Conclusions Mode of ventilation during CPB did not affect immediate postbypass oxygenation.