Short-long term near infrared spectroscopy patterns after different milk regimens olfactory stimuli in late preterms

Background: The aim of the study is to investigate the effects of olfactory stimuli from breast and formula milk on near-infrared spectroscopy (NIRS) cerebral and splanchnic patterns in late preterm infants. Methods: We conducted a multicenter prospective observational pretest-test study in 30 late preterm infants subjected to olfactory stimuli from breast and formula milk. Regional oxygenation status, tissue function in cerebral and splanchnic districts, and cerebral-splanchnic hemodynamic redistribution were recorded at four pre-determined time-points: before sniffing (30 min), during sniffing (30 s), short-term (30 min), and long-term after olfactory stimuli (180 min). Results: After olfactory stimuli from breast and formula milk we found: (i) a significant increase (p < 0.05) in cerebral oxygenation and cerebral-splanchnic hemodynamic redistribution after breast milk stimulus, (ii) a significant increase (p < 0.05) in splanchnic oxygenation and splanchnic-cerebral hemodynamic redistribution after formula milk stimulus. Conclusions: The present results show early changes in NIRS patterns in cerebral and splanchnic districts after breast and formula milk stimuli. Data opens the way to further studies using NIRS as a reliable tool for central nervous system and splanchnic development and response after olfactory stimuli.