Mechanisms of cough provocation and cough resolution in neonates with bronchopulmonary dysplasia

Area of Science:

• Pediatric Gastroenterology
• Neonatology
• Respiratory Medicine

Background:

• Cough and deglutition are crucial protective reflexes preventing aspiration.
• Infants with bronchopulmonary dysplasia (BPD) often experience impaired protective airway reflexes.
• Understanding cough mechanisms in BPD is vital for preventing aspiration and improving infant outcomes.

Purpose of the Study:

• To identify the specific mechanisms triggering cough events in infants with BPD.
• To elucidate the mechanisms responsible for resolving coughs and restoring normalcy in these infants.
• To analyze the association between esophageal motility patterns and cough clusters in premature infants with BPD.

Main Methods:

• Concurrent esophageal manometry, respiratory inductance plethysmography, and nasal airflow measurements were used in 16 premature infants with BPD.
• Analysis focused on manometry signatures of cough, including pretussive and post-tussive pharyngo-esophageal motility.
• 312 cough events within 88 cough clusters were analyzed for associated mechanisms.

Main Results:

• 97% of cough events had recognizable manometric patterns.
• Common initial cough triggers included non-propagating swallows (59%), upper esophageal sphincter (UES) reflex contraction (18%), and lower esophageal sphincter (LES) relaxation (14%).
• UES and LES dysfunction was noted in 69% of cough clusters associated with non-propagating swallows. Infants on nasal continuous positive airway pressure (NCPAP) showed a higher association of UES contraction reflex with cough clusters (OR = 9.13).

Conclusions:

• Cough clusters in infants with BPD have identifiable etiologies linked to esophageal events.
• Initial cough mechanisms frequently originate from the upper aerodigestive tract.
• Peristaltic reflexes are the primary mechanisms for resolving coughs and restoring esophageal and respiratory normalcy.