MECHANISMS OF OBSTRUCTIVE SLEEP APNEAS IN INFANTS

During sleep, infants with obstructive sleep apneas are characterised by snoring, laborious breathing, and profuse sweating. During wakefuln ess, they may have breath-holding spells, and during feeding, difficul t breathing and swallowing coordination. Abnormal weight, difficult gr owth, and recurring ear infections may also develop. During sleep apne as, cinefluoroscopy shows approximation of tongue and hypopharyngeal t issues, with an obliteration of the air space. The obstructed breaths occur mainly in REM, and light NREM sleep, associated with total short sleep time, and frequent arousals. Preterm infants, and term neonates are more prone to obstructive apneas than older healthy infants. Apne as are more frequently seen in boys and in case of excess in body weig ht. Obstructive apneas are frequently associated with upper airway ana tomic abnormalities: malformations, soft tissue infiltration, and neur ologic lesions impairing muscle contractions. Alterations of the auton omic nervous control may induce airways obstructions. Contributing fac tors include mucopolysaccharide storage disease, hypothyroidism, or Do wn's syndrome. Superimposed factors may occur, such as nasal obstructi on, secretions in the airways, or tissue edema. Pressure- and chemo-se nsitive reflexes may also favor obstruction. Environmental factors als o contribute to the development of sleep apneas: body position, neck f lexion, sleep deprivation, or the effects of sedative drugs.