Abstract
The aim of the study was to identify daytime predictors of nocturnal gas exchange anomalies in children with neuromuscular disease (NMD) and normal daytime gas exchange.
Lung function tests, respiratory muscle evaluation and nocturnal gas exchange were obtained as part of routine evaluation.
We included 52 consecutive children with Duchenne muscular dystrophy (n=20), spinal muscular atrophy (n=10), and other NMD (n=22). Twenty patients had nocturnal hypoxemia defined by minimal pulse oximetry (SpO2) <90% for at least 2% of night time and 22 had nocturnal hypercapnia defined by maximal transcutaneous carbon dioxide (PtcCO2) value >50 mmHg for at least 2% of night time. Forced vital capacity and helium functional residual capacity correlated with minimal nocturnal SpO2 (p=0.009 and p=0.01, respectively). Daytime pH correlated negatively with maximal nocturnal PtcCO2 (p=0.005) and daytime Pa,CO2 correlated with the percentage of time with a PtcCO2>50 mmHg (p=0.02). Sniff nasal inspiratory pressure correlated with minimal nocturnal SpO2 (p=0.02). Daytime Pa,CO2 was a weak predictor of nocturnal hypercapnia (sensitivity 80%, specificity 57%).
Daytime lung function and respiratory muscle parameters correlate poorly with nocturnal hypoxemia and hypercapnia in children with NMD and normal daytime gas exchange which pleads for more systematic sleep studies in these children.
- ERS