Sleep-disordered breathing in children with thoracic insufficiency syndrome

Thoracic insufficiency syndrome (TIS) is a collection of chest and spine malformations that results in progressively restrictive pulmonary mechanics and an inability of the thorax to adequately support lung growth. Many children with TIS are too young to perform standard pulmonary function tests, yet need functional assessments of their restrictive thoracic disease. We report on the sleep architecture and frequency of sleep-related breathing abnormalities in 11 children with TIS who underwent overnight polysomnography from retrospective chart review. Ten of 11 (92%) had sleep disordered breathing as defined by currently accepted criteria of apnea-hypopnea index (AHI) >2 events/hr. The median AHI was 4.3 events/hr, with obstructive hypopneas (median 3.7 events/hr) accounting for 75% of abnormalities. Respiratory events occurred most frequently during REM sleep (median REM-AHI 17.3 events/hr), and were associated with oxyhemoglobin desaturation, and rarely carbon dioxide retention. Sleep disordered breathing with hypoxemia appears to be a common but under recognized problem among children with TIS. Polysomnogram may have a role as a non-invasive screening tool used in conjunction with other functional respiratory assessments in children with TIS, and warrants further study in a prospective manner.