Cardiopulmonary Effect of Mechanical Ventilation in Children With Right Ventricular Hypertrophy

Cardiopulmonary Effect of Mechanical Ventilation in Children Underwent Surgical Repair of Right Ventricular Hypertrophy: Compared With Pressure Control Ventilation, Pressure Support Ventilation and Neurally Adjusted Ventilatory Assist

Neurally adjusted ventilatory assist (NAVA) is a new mode of mechanical ventilation that delivers ventilatory assist in proportion to neural effort. The investigators hope to compare the hemodynamic and pulmonary effect in children after surgical repair of congenital heart disease with right ventricular hypertrophic ventilated with Pressure control ventilation (PCV), Pressure support ventilation (PSV), and NAVA by a crossover study.

In the patients suffered from congenital heart disease with right ventricular hypertrophy, the preload of the heart will be influenced by the variation of the intrathoracic pressure. The cardiopulmonary interaction during mechanical ventilation will be an important influence factor on hemodynamics after surgical repair for these patients. As a new mode of mechanical ventilation, NAVA delivers ventilatory assist in proportion to patients' neural effort avoiding over ventilation.

The investigators designed a crossover study to evaluate the cardiopulmonary effect in patients with congenital heart disease with right ventricular hypertrophy when ventilated with NAVA postoperatively, compared with the conventional mode of pressure control ventilation and pressure support ventilation. Each patient will undergo three 60-min trials during the study period in randomized order. The cardiac output and volume status will be evaluated by a transpulmonary thermodilution device through a pulse contour cardiac output (PiCCO) catheter at the last 10min of each trial. At the mean while an arterial blood gas and echocardiography will perform.

Data are expressed as mean ± standard deviation. Datas from the three registrations will be compared using a repeated-measures ANOVA. The comparison of each mode will be assessed by the SNK methods post hoc test. A p value of less than 0.05 was considered significant.

Inclusion Criteria:

1. Patients underwent surgical repair of right ventricular hypertrophic congenital heart disease
2. Obtain informed consent signed by parents

Exclusion Criteria:

1. Significant residual shunt (more than 2mm), residual obstruction of right ventricular outflow tract (RVOT) or A-V valve insufficiency.
2. Hemodynamic instability (whose inotropic score more than 20);
3. Significant bleed (whose chest drainage more than 5ml/kg/h);
4. Failed to insert the PiCCO catheter
5. Dysfunction and abnormal of esophage;
6. Inclusion in other research protocol