Infants are not obligatory nasal breathers

Area of Science:

• Neonatal Physiology
• Respiratory Regulation in Infants

Background:

• The prevailing belief is that infants exclusively breathe through their noses.
• Understanding infant respiratory mechanisms is crucial for clinical care.

Purpose of the Study:

• To investigate the respiratory response of infants to acute nasal occlusion.
• To determine if infants can switch to oral breathing when nasal airflow is obstructed.

Main Methods:

• Studied 19 infants (1-230 days old) with acute nasal occlusion and open lips.
• Monitored oropharyngeal structures via fluoroscopy and recorded respiratory movements and oral airflow.
• Observed the response in infants with both open and closed mouths, and recorded EEG in some.

Main Results:

• Infants demonstrated tight apposition of the soft palate and tongue, blocking oral airflow.
• Upon nasal occlusion, infants initiated oral breathing after a mean of 7.8 seconds by raising the soft palate.
• The time to initiate mouth breathing correlated with age and state (awake infants responded faster).
• Nasal occlusion in sleeping infants triggered arousal followed by mouth breathing.

Conclusions:

• Infants are capable of mouth breathing and are not obligatory nasal breathers.
• The oropharyngeal isthmus can be opened by detaching the soft palate from the tongue.
• Infant respiratory flexibility is influenced by age and arousal state.