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 sat uration (Sao2; Nellcor N200 in beat-to-beat mode), photoplethysmograph ic 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 greater-than-or-equal-to 4 seconds (apneic paus es), for episodes in which Sao2 fell to less-than-or-equal-to 90% (des aturations) and, only during the state of regular breathing, for basel ine Sao2, heart rate, and respiratory rate. Results. Both baseline hea rt rate and respiratory rate decreased with increasing age (r = -.7 an d -.3, respectively, P < .01). Baseline Sao2 was similar to that previ ously observed in infants (median 99.5%, range 95.8 to 100, 5th centil e 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 1 9.9 seconds, and 23 lasted for greater-than-or-equal-to 20 seconds (lo ngest 28.8 seconds). The number of episodic falls in SaO2 to less-than -or-equal-to 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 f requency in the total group was 0.6/h. In six episodes in four patient s, Sao2 fell to less-than-or-equal-to 80%. Conclusions. Apneic pauses, some of which can last for more than 20 seconds, are a normal phenome non in healthy children and adolescents, but only a small minority of apneic pauses affect blood gas homeostasis. Information concerning oxy genation may be more relevant to our understanding of the maturation o f respiratory control than the recording of breathing signals alone.