Oral breathing in newborn infants

Area of Science:

• Neonatal Physiology
• Respiratory Medicine

Background:

• Newborn infants are traditionally considered obligate nasal breathers, relying solely on a patent nasal airway for respiration.
• Understanding the conditions and extent of oral breathing in neonates is crucial for assessing airway patency and respiratory function.

Purpose of the Study:

• To investigate the conditions under which healthy term infants utilize oral breathing.
• To quantify the contribution of oral ventilation to overall breathing in newborns.
• To assess the physiological responses during oral breathing in neonates.

Main Methods:

• Simultaneous measurement of nasal and oral airflow using pneumotachometers in 30 healthy term infants (1-3 days old).
• Continuous monitoring of heart rate, transcutaneous oxygen (tcPO2), end-tidal carbon dioxide (etCO2), and sleep state.
• Induction of oral breathing via nasal occlusion in a subset of infants.

Main Results:

• Spontaneous oronasal breathing occurred in 30% of undisturbed sleep, with 30% of tidal volume via the oral route.
• Oral breathing episodes were observed post-crying in some infants.
• 40% of infants initiated sustained oral breathing during nasal occlusion, without significant changes in respiratory rate, heart rate, or tcPO2.

Conclusions:

• Newborn infants possess the capability for oral ventilation, challenging the strict definition of obligate nasal breathing.
• Oral breathing can be initiated spontaneously or in response to nasal obstruction, indicating adaptability in neonatal respiratory control.
• The findings suggest that the oral airway serves as a viable compensatory route for ventilation in neonates.