Noninvasive ventilation in children with spinal muscular atrophy types 1 and 2

OBJECTIVE: Our aim was to assess the efficacy of noninvasive ventilation (NIV) for the treatment of thoracoabdominal asynchrony during sleep in children with spinal muscular atrophy (SMA) types 1 and 2. DESIGN: Nine subjects underwent assessment for sleep apnea/hypopnea index (AHI), mean oxyhemoglobin saturation (SpO2), oxygen desaturation index, transcutaneous carbon dioxide tension (tcpCO2), and mean phase angle during sleep as a measure of thoracoabdominal coordination. A second sleep study was performed with use of NIV. RESULTS: The nine patients (7 mos of age, range 2-33) had a baseline AHI of 2.1 events per hour (range 0.5-55.8), oxygen desaturation index of 3.7 events per hour (range 1.6-46.1), mean tcpCO2 of 46 mm Hg (range 37-60), and phase angle of 127 degrees (range 72.7-151.7). Comparing baseline and NIV sleep studies, we found significant improvement in oxygen desaturation index (P <0.010), mean tcpCO2 (P <0.001), and phase angle (P <0.001). For five patients, phase-angle improvement became significant when using high-span bilevel positive airway pressure (PAP). CONCLUSIONS: NIV improved sleep breathing parameters and thoracoabdominal coordination during sleep in SMA types 1 and 2. Phase-angle improvement correlated with bilevel PAP pressures. Phase angle may be useful for the evaluation and monitoring of therapeutic interventions such as NIV.