Oxygen saturation during the first 24 hours of life

Aim-To determine normative data for arterial oxygen saturation, measured by pulse oximetry (SpO(2)), in healthy full term infants throughout their fir st 24 hours of life. Methods-Long term recordings of SpO(2), pulse waveform, and breathing movem ents were made on 90 infants. Recordings were analysed for baseline SpO(2), episodes of desaturation (SpO(2) less than or equal to 80%), apnoeic pause s of greater than or equal to four seconds, and periodic apnoea (greater th an or equal to three apnoeic pauses, each separated by less than or equal t o 19 breaths). Results-Median baseline SpO(2) was 98.3% (range 88.7-100), Longitudinal ana lysis at four hour intervals showed that SpO(2) remained stable until 20-24 hours of age, when it became significantly lower (p < 0.03). Episodic desa turations were identified in 23 recordings. Nine prolonged desaturations (S pO(2) less than or equal to 80% for greater than or equal to 20 seconds) we re identified in six recordings. Four desaturations fell to less than or eq ual to 60%. Periodic apnoea was identified in 60% of recordings. Conclusion-The range of SpO(2) during the first 24 hours of life is similar to that found previously during the first month of life. The clinical sign ificance of the prolonged episodes of desaturation observed justifies furth er investigation.