Effectiveness of prophylactic non-invasive ventilation on respiratory function in the postoperative phase of pediatric cardiac surgery: a randomized controlled trial

Objective To evaluate the effectiveness of prophylactic, non-invasive ventilation (NIV) on respiratory function in seven- to 16-year-old children in the post-operative phase of cardiac surgery. Method A randomized, controlled trial with 50 children who had undergone cardiac surgery with median sternotomy. After extubation, patients were randomly assigned to one of two groups: control group (n=26), which received instructions regarding posture, early ambulation, and cough stimulation, and CPAP group (continuous positive airway pressure; n=24), which received the same instructions as the control group and CPAP=10 cmH20 twice daily for 30 minutes from the 1st to the 5th post-operative day (POD). As a primary outcome, lung function was evaluated before and on the 1st, 3rd, and 5th PODs with measures of respiratory rate (RR), tidal volume (TV), slow vital capacity (SVC), inspiratory capacity (IC), minute volume (MV), peak expiratory flow (PEF), and maximal inspiratory pressure (MIP). As secondary outcomes, the time of hospitalization and intensive care were recorded. A mixed, linear regression model and z-test were used to analyze respiratory function, considering p<0.05. Results All variables, except RR and MV, showed a significant drop on the 1st POD, with gradual recovery; however, only MIP had returned to pre-operative values on the 5th POD in both groups. The RR showed a significant increase on the 1st POD, with a gradual reduction but without returning to baseline. In the intergroup analysis, significant improvement (p=0.04) was observed only in PEF in the CPAP group on the 1st DPO. The length of hospitalization and intensive care showed no significant differences. Conclusion NIV was safe and well accepted in this group of patients, and the protocol used was effective in improving PEF on the 1st DPO in the CPAP group.