Response in the newborn to raised upper airway resistance.

The effect of raising the airways resistance of 56 normal newborn babies by blocking alternate nostrils was studied by means of oesophageal intubation and the trunk plethysmograph. Increased resistance was associated with reduced respiratory rate and ventilation. A comparison was made of the response in different sleep states. In rapid eye movement (REM) sleep respiratory tidal volume decreased on blocking, there was no increase in the work of breathing and the fall in minute volume was greater than in non-REM sleep where tidal volume and minute work increased on blocking. These responses may be relevant to the sudden unexpected death syndrome in infancy, and to the management of normal newborns.