Oxygen saturation and breathing patterns in children.

OBJECTIVE

To obtain information on breathing patterns and oxygenation in children.

DESIGN

Overnight tape recordings of arterial oxygen saturation (SaO2; Nellcor N200 in beat-to-beat mode), photoplethysmographic waveforms, and breathing movements in 70 healthy children (mean age 8.0 years, range 2 through 16). Analysis of recordings for pauses in breathing movements of > or = 4 seconds (apneic pauses), for episodes in which SaO2 fell to < or = 90% (desaturations) and, only during the state of regular breathing, for baseline SaO2, heart rate, and respiratory rate.

RESULTS

Both baseline heart rate and respiratory rate decreased with increasing age (r = -.7 and -.3, respectively, P < .01). Baseline SaO2 was similar to that previously observed in infants (median 99.5%, range 95.8 to 100, 5th centile 96.6%). Every recording showed apneic pauses, with a frequency that did not vary consistently with age (median 7.7/h, range 0.6 to 25.5). One hundred nineteen apneic pauses in 43 recordings lasted for 15 to 19.9 seconds, and 23 lasted for > or = 20 seconds (longest 28.8 seconds). The number of episodic falls in SaO2 to < or = 90% decreased with age (r = -.3, P < .01); such episodes were found in 47% of children aged 2 through 6 years, but in only 13% of those aged 12 through 16 years. The 95th centile for desaturation frequency in the total group was 0.6/h. In six episodes in four patients, SaO2 fell to < or = 80%.

CONCLUSIONS

Apneic pauses, some of which can last for more than 20 seconds, are a normal phenomenon in healthy children and adolescents, but only a small minority of apneic pauses affect blood gas homeostasis. Information concerning oxygenation may be more relevant to our understanding of the maturation of respiratory control than the recording of breathing signals alone.