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The maturation changes of sleep-related respiratory abnormalities in infants with laryngomalacia.

STUDY OBJECTIVES
Obstructive sleep apnea (OSA) and central sleep apnea (CSA) are common in infants with laryngomalacia. The purpose of this study was to evaluate 1) developmental changes in sleep-related breathing disorders over time in infants with laryngomalacia and 2) understand the effect of supraglottoplasty and non-surgical treatment.


METHODS
This is a retrospective review of infants with laryngomalacia who had at least two diagnostic polysomnography (PSG) performed from January 2000 and May 2015. We included infants who had either OSA or CSA. Comparison of sleep and respiratory parameters by age group (0-6 months old, 6-12 months old and > 12 months old) was performed in both supraglottoplasty (SGP) and non-supraglottoplasty (non-SGP) groups using mixed-effect regression model. Lognormal mixed model was used to explore the changes in sleep and respiratory parameters with age. The time to resolution of CSA and OSA were analyzed using non-parametric survival analysis.


RESULTS
102 infants were included; 57 had only OSA and 45 had both CSA and OSA. There were significant decreases in apnea hypopnea index, obstructive index (OI), central apnea index (CI) and arousal index with increasing age in both SGP and non-SGP group. The mean age at resolution of CSA (CI<5) was 7.60 months old for SGP and 12.57 months old for non-SGP (P<0.05). There was no significant differences in the mean age at resolution of OSA (OI<1; 35.18 [SGP] vs 41.55 months [non-SGP]; P=0.60) between SGP and non-SGP groups. Infants with neurological disease, congenital anomalies or genetic syndromes required significantly more time to resolve OSA (28.12 [normal] vs 53.13 [neurological] vs 59.53 months [congenital anomalies & genetic]; P<0.01).


CONCLUSIONS
Both OSA and CSA improve in infants with laryngomalacia with increasing age regardless of SGP. The mechanism underlying these changes may involve airway growth and maturation of respiratory control. Time to resolution of OSA is affected by the presence of neurological diseases, congenital anomalies and genetic syndromes. Further studies are needed to confirm these findings and to evaluate long term outcomes in this population.