CARDIORESPIRATORY FUNCTIONING OF PRETERM INFANTS - STABILITY AND RISKASSOCIATIONS FOR MEASURES OF HEART-RATE-VARIABILITY AND OXYGEN-SATURATION

Cardiorespiratory measures are used with increasing frequency to asses s individual differences in development in full-term and preterm infan ts, yet little information exists concerning the stability of these me asures or their relations to each other. This study assessed three com mon cardiac measures (heart period, heart period variability, and vaga l tone) and two measures of arterial oxygenation based on pulse oximet ry (mean pulse oxygen saturation and variability) in a sample of 35 pr eterm infants. Data were collected on five occasions: on 3 consecutive days in the early neonatal period, at 34 weeks postconceptional age, and at discharge. Results indicate both short-term and longer term sta bility for all cardiac measures. Oxygen saturation demonstrated only s hort-term stability prior to 34 weeks. Mean heart period was positivel y associated with both measures of heart period variability at each as sessment point, while mean oxygen saturation level was inversely relat ed to oxygen saturation variability. In addition, significant associat ions between cardiorespiratory patterns and perinatal risk measures we re found. It is concluded that these measures reflect stable character istics of neuroregulatory function in preterm infants. (C) 1994 John W iley and Sons, Inc.