The effect of nasal obstruction in infancy and early childhood upon ventilation.

To evaluate the effect of nasal obstruction in infants and young children upon ventilation during sleep, change of ventilation was followed by polygraphic recordings of esophageal pressure, tidal volume and percutaneous oxygen tension when the nostrils were mechanically obstructed in 10 subjects; 3 types of ventilatory changes were noted. In 4 subjects periodic breathing appeared in which hypoventilation was alternated with occasional hyperventilation. Esophageal pressure, tidal volume and PO2 showed concomittant fluctuation. PO2 lowered during hypoventilatory phase was compensated by periodic hyperventilation. In 5 subjects upper airway obstruction was compensated for by increased respiratory endeavor and tidal volume and PO2 remained normal in spite of markedly increased esophageal pressure. In 1 subject tidal volume and PO2 remained decreased with marked increase of esophageal pressure. Largest airway obstruction was noted between the upper and the lower lips.