Utilizing the Infant's Capacity to Smell to Mitigate Painful Procedures

Providing relief for infants undergoing painful procedures should be a basic routine of management of care in every newborn nursery, and most importantly in the treatment protocols of every newborn intensive care unit. To date, the efficacy of nonpharmacologic interventions in reducing pain and stress as measured by neonatal behavioral and physiologic responses and/or by biochemical (cortisol) levels has been repeatedly substantiated.^1,2 In particular, there is convincing evidence of the effectiveness of the nonpharmacologic techniques in term infants of breastfeeding, oral feeding of mother's own breastmilk, and feeding of sucrose. In addition, kangaroo care has been demonstrated in premature infants to be successful in reducing pain responses.

Unfortunately, as strong as the evidence is for the effectiveness of these procedures in term infants, to date, the data in their use in the care of the preterm infant are relatively limited. Furthermore, the realities of intensive care for the sick preterm infant at times minimize the opportunity for close physical contact with the mother, thus precluding both breastfeeding and kangaroo care. Likewise, in such critical and unstable clinical situations, oral feeding, be it of breastmilk or sucrose, is frequently prohibited.

Thus, the publication of the study of Jebreili et al. ³ in this issue of Breastfeeding Medicine is of major interest as it confirms that there are alternative nonpharmacologic interventions that can used, even in those situation wherein the clinical status of the infant precludes direct tactile contact with mother or oral feedings. Capitalizing on the olfactory capacity of the newborn (even the preterm), the authors demonstrated that exposing the infant to the odor of the mother's own breastmilk as opposed to other odors will have a significant effect of mitigating pain response to venipuncture. Most importantly, the success of the milk odor rested on the fact that the milk was presented to infants were who already exposed to their mother's own milk in previous feeds. This emphasizes once again the value of early feeding of mother's own milk to the sickest infants so as to establish the physiological basis for pain relief. The fact that the newborn has the capacity for olfactory recognition, as it is a non–cortical-dependent memory sensory modality, is matched by the mother's own capacity for olfactory recognition of her infant. ⁴ This supports the conclusion that early proximal contact of the mother and infant is an integral component of the attachment process and provides potential benefits beyond nutrition.

That the components of breastmilk are not of a fixed concentration or ratio is a truism, but is a fact that needs to be reemphasized over and over again. Standardized textbooks, unfortunately, still publish tables comparing human breastmilk with bovine milk or with formula with the levels seemingly chiseled in stone. That the breastmilk components vary from the onset of the nursing period to the end (foremilk versus hindmilk) over the days and weeks postpartum and by means of expression and are adjusted to the needs of the infant is the reality. The importance of studies of Mangel et al. ⁶ and Moran-Lev et al. ⁶ published in this issue is that they confirm this dynamic aspect of the macronutrient components of breastmilk.