The role of obstructive apnea in sudden infant death syndrome and apparent life threatening event.

In sudden infant death syndrome (SIDS) apnea is the terminal event; whether or not an obstructive apnea is the primary event is unknown. Collapse of the pliable pharyngeal airway during life would not be detected after death and is therefore hard to prove. The distinctive distribution of petechiae at necropsy can be explained by negative intrathoracic pressure before death suggesting upper airway obstruction. Obstructive sleep apneas have been documented in subsequent SIDS victims: however, polysomnography is not predictive for individual infants. It is unknown how many ALTE (apparent life threatening event) infants would have died of SIDS without intervention. About 4-10% of these events are caused by upper airway obstruction. There have been well documented cases of ALTE infants who in time developed the symptoms of obstructive sleep apnea syndrome (OSAS). Obstructive apnea certainly causes some cases of ALTE; whether it also causes a subgroup of SIDS is unknown.