Nonlinear methods of analysis to examine respiratory waveform variability during oral feeding in preterm infants

In a novel exploratory study, nonlinear methods of analysis for respiratory patterns were used to examine respiratory waveform variability during oral feeding in preterm infants. Twelve healthy preterm infants were studied using a within-subject cross over design to compare semi-upright and the elevated sidelying position during bottle feeding. Outcome measures were physiologic indicators of cardiopulmonary status: heart rate, respiratory rate, oxygen saturation and respiratory pattern variability. Preliminary results suggest that analysis of respiratory waveform variability is feasible and may be a more sensitive measure of cardiopulmonary physiology than means for heart rate, respiratory rate and percent haemoglobin oxygen saturation. Nonlinear methods of analysis of the respiratory data provide a distinct perspective on the adaptability of infants' breathing patterns while feeding. The clinical application of monitoring respiratory waveforms using nonlinear methods may be helpful in identifying readiness to initiate and advance feeds orally in preterm infants.