Variation of oxygen saturation during periodic breathing

Objektives: Periodic variations of oxygen saturation are often found in infants during periodic breathing. Aim of this study was to examine this phenomenon more systematically. Methods: ECG, respiration and arterial oxygen saturation (pulse oximetry) were recorded on 104 preterm and 100 term infants (mean sleep recording time 14.2 hours). In 15 infants showing marked variations of oxygen saturation additional simultaneous oxyten saturation measurements at the right hand and foot were performed. Results: 98 % of preterm and 57 % of term infants showed periodic oxygen saturation variations during periodic breathing. The peak to peak amplitude of oxygen saturation was between 2 and 35 % with fall and rise times of 3.0-8.1 secends. The simultaneous measurements showed significantly higher variations at the foot. Conclusions: Periodic breathing is accompanied by periodic variations of oxygen saturation in a high percentage. Some infants showed acute hypoxaemia during these episodes. According to our results of simultaneous oxygen saturation measurements a periodically occurring, intermittent right to left shunting via the foetal circulation pathways is discussed as an explanation.