A pilot study: the role of the autonomic nervous system in cardiorespiratory regulation in infant feeding.

AIM The purpose of this pilot study was to examine the interplay between the parasympathetic (PNS) and sympathetic nervous systems' (SNS) contributions to prefeeding, feeding and satiation in young, healthy infants. METHOD This prospective study was completed on eleven full-term infants, less than 6 months old. Respiratory rate, heart rate, heart rate variability (HRV), electrodermal activity and low-frequency/high-frequency heart rate variability ratio were sampled from the infant during prefeeding, feeding and satiation periods. RESULTS A repeated-measures ANOVA revealed a significant difference in respiratory patterning during the three feeding phases (p = .049); however, none of the other physiological measures reached significance. An emerging trend across physiological measures suggests that the feeding phase was influenced by the SNS with increasing respiratory rate, heart rate, low-frequency HRV, electrodermal activity and decreasing high-frequency HRV compared to the prefeeding and satiation phases, which were influenced predominantly by the PNS. CONCLUSION Respiration rate increased significantly during the feeding phase compared to prefeeding and postfeeding phases. Emerging trends indicate a pattern of alternating relative tone in PNS versus SNS across feeding phases - with SNS predominating the feeding phase. More clinical research examining the SNS and PNS contributions to feeding should be completed across patient populations.