Related Experiment Videos
Pharyngeal fluid clearance and aspiration preventive mechanisms in sleeping infants
D L Pickens1, G L Schefft, B T Thach
1Edward Mallinckrodt Department of Pediatrics, Children's Hospital, Washington University School of Medicine, St. Louis, Missouri 63110.
Insights
Pharyngeal stimulation during sleep in infants can trigger various airway protective responses. Preterm infants showed significantly more frequent and prolonged responses compared to full-term infants.
Area of Science:
- Pediatric Sleep Medicine
- Neonatal Physiology
- Respiratory Control
Background:
- Infants possess complex ventilatory and airway protective reflexes during sleep.
- Understanding these responses is crucial for managing respiratory health in neonates, particularly those with apnea history.
Purpose of the Study:
- To characterize infant ventilatory and airway protective responses to pharyngeal stimulation during sleep.
- To investigate the influence of stimulus intensity and fluid relation to laryngeal structures on these responses.
- To compare responses between healthy full-term and preterm infants with a history of apnea.
Main Methods:
- Studied healthy full-term (n=5) and preterm infants (n=9) with a history of prolonged apnea during sleep.
- Administered small boluses of warm saline (0.02-0.35 ml) to the oropharynx via a nasopharyngeal catheter.
- Observed and recorded responses including swallows, obstructed breathing, apnea, and cough, noting frequency and relation to stimulus parameters and infant group.
Main Results:
- Swallows and obstructed breaths were frequent in both groups; cough and prolonged apnea were infrequent.
- Increased stimulus volumes led to more frequent responses (P<0.01).
- Preterm infants exhibited significantly more frequent responses than full-term infants (P<0.01), with prolonged apnea being more common.
Conclusions:
- Pharyngeal stimulation elicits diverse protective responses in infants during sleep.
- Preterm infants demonstrate heightened responsiveness, suggesting potential differences in airway protection mechanisms.
- The anatomical relationship between the piriform fossae and interarytenoid notch may influence response frequency, impacting upper airway secretion clearance during sleep.
Abstract:
We sought to characterize ventilatory and airway protective responses to pharyngeal stimulation in young infants during sleep. We studied the various responses with respect to frequency of occurrence, effect of increased stimulus intensity, and relation of stimulus fluid to laryngeal structures. Two groups of infants were studied: healthy full-term infants (n = 5) and preterm infants with a history of prolonged apnea (n = 9). We used a nasopharyngeal catheter to deliver small boluses of warm saline (0.02-0.35 ml) to the oropharynx. Responses repeatedly observed in both infant groups included swallows, obstructed respiratory efforts, brief apnea, prolonged apnea, and cough. In both infant groups, swallows and obstructed breaths occurred frequently and cough and prolonged apnea infrequently. The functional significance of some response patterns was clear, whereas that of others was obscure. Larger stimulus volumes yielded more frequent responses (P less than 0.01), and preterm infants responded much more frequently than full-term infants (P less than 0.01). Prolonged apnea was a composite of the other responses and was much more common in preterm than full-term infants (P less than 0.01). The stimulus technique was performed under direct visualization of the airway in two deceased infants. The findings suggested that the relation of the piriform fossae to the interarytenoid notch is important in determining response frequency. Implications for regulation of the removal of upper airway secretions during sleep are discussed.