Prone position increases collapsibility of the passive pharynx in infants and small children

Area of Science:

• Pediatric Sleep Medicine
• Respiratory Physiology
• Sudden Infant Death Syndrome (SIDS) Research

Background:

• Avoiding the prone sleeping position has been linked to a decreased incidence of sudden infant death syndrome (SIDS).
• Obstructive sleep apnea is closely associated with SIDS, suggesting a potential role for upper airway function.

Purpose of the Study:

• To investigate the hypothesis that the prone sleeping position increases upper airway collapsibility in infants and young children.
• To quantify changes in passive pharyngeal collapsibility across different sleeping postures.

Main Methods:

• Evaluated passive pharyngeal collapsibility in 19 infants and young children (10-101 weeks old).
• Measurements were taken in three postures: supine (face up), supine with neck rotated, and prone with neck rotated.
• Assessed maximal pharyngeal distension, pharyngeal stiffness, and pharyngeal closing pressure using static pressure-area relationships.

Main Results:

• Maximal pharyngeal distension was significantly reduced in the prone position compared to the supine position (p < 0.05).
• Pharyngeal closing pressure increased significantly in the prone position compared to the supine position with neck rotation (p < 0.05).
• In the prone position, half of the subjects exhibited pharyngeal closing pressure above atmospheric pressure, unlike the supine position where all subjects had negative pressure.

Conclusions:

• The prone sleeping position demonstrably increases upper airway collapsibility in infants and young children.
• This increased collapsibility may be a contributing factor to the observed link between prone sleeping and SIDS.
• The precise physiological mechanisms underlying this increased collapsibility in the prone position require further investigation.