[Airway pressure release in postoperative cardiac surgery in pediatric patients].

OBJECTIVE: Comparison of three modes of MV: intermittent mandatory ventilation with positive end expiratory pressure (IMV + PEEP), APRV and continuous positive airway pressure (CPAP) in children during cardiac surgery post operative with pulmonary hypertension and mild or moderate pulmonary lesion.

METHODS: Ten patients were studied with respiratory monitoring (Bear Neonatal Volume Monitor-1) in MV with a continuous flow, time cycled and pressure limited ventilator. The cardiocirculatory variables analyzed were central venous pressure (CVP), oxygen extraction ratio, cardiac rate, systolic arterial pressure, and arterial-mixed venous CO2 difference. Friedman's test (nonparametric) was used to compare the variables in three modalities of ventilation and the Wilcoxon test was used for the variables obtained in two of the modalities.

RESULTS: The mean airway pressure (MAP) showed a significant increasing during APRV compared to IMV + PEEP (p = 0.012). The positive inspiratory pressure (PIP), the minute volume and the ratio of oxygen arterial pressure to oxygen inspired fraction (PaO2/FiO2) didn't show statistical difference. During APRV there was a significant decrease in respiratory rate (p = 0.004) and an increase in tidal volume (p = 0.045) when compared to CPAP and IMV + PEEP. In the cardiocirculatory system only CVP showed a significant increased (p = 0.019) during APRV.

CONCLUSION: Due to the methodology utilized MAP was higher with APRV resulting in an increased tidal volume without respiratory or cardiocirculatory adverse effects when the three modes were compared. Our results suggest that APRV is a simple and safe method of ventilation.