Assessment of a hearing protection device on infant sleep in the neonatal intensive care unit.

Premature infants often require prolonged hospitalisation in the neonatal intensive care unit (NICU) where they are exposed to adverse noise that may disrupt sleep and further compromise recovery and developmental outcomes. This single-session trial assessed the effects of a novel circumaural hearing protection device (DREAMIES®; NEATCAP Medical LLC) on sleep in 10 premature infants (mean 34.1 weeks GA) in a Level III NICU. Using polysomnography (PSG), the infant's sleep was compared between three interfeed periods throughout which DREAMIES® was ON or OFF. Each infant received the same condition order, OFF1-ON-OFF2. The PSG 30 s epochs were scored by a rater masked to the condition as Quiet Sleep, Active Sleep, Indeterminate Sleep, and Wake. There was a 14.1% increase in sleep from OFF1 to ON (p = 0.05) and an 18.4% decrease in sleep from ON to OFF2 (p = 0.02); an analogous inverse effect was observed for wake (χ2  = 5.03, p = 0.08). There was a main effect of DREAMIES on active sleep (χ2  = 7.4, p = 0.025) due to more active sleep for ON1 (46%) compared with OFF2 (32%; p = 0.074). No significant effect was observed for quiet sleep or indeterminate sleep. On average, the sound level was 51 dBA (range 36-113 dBA) and did not differ significantly among the three periods. The strongest relationship between the minute-by-minute maximum sound level and movement actigraphy was observed for the OFF1 condition (ρ0.301, p < 0.001). These findings suggest that DREAMIES® may augment sleep in premature infants by reducing acute episodes of adverse noise in the NICU.

Assessment of cardio-respiratory interactions in preterm infants by bivariate autoregressive modeling and surrogate data analysis.

BACKGROUND: Cardio-respiratory interactions are weak at the earliest stages of human development, suggesting that assessment of their presence and integrity may be an important indicator of development in infants. Despite the valuable research devoted to infant development, there is still a need for specifically targeted standards and methods to assess cardiopulmonary functions in the early stages of life. We present a new methodological framework for the analysis of cardiovascular variables in preterm infants. Our approach is based on a set of mathematical tools that have been successful in quantifying important cardiovascular control mechanisms in adult humans, here specifically adapted to reflect the physiology of the developing cardiovascular system. METHODS: We applied our methodology in a study of cardio-respiratory responses for 11 preterm infants. We quantified cardio-respiratory interactions using specifically tailored multivariate autoregressive analysis and calculated the coherence as well as gain using causal approaches. The significance of the interactions in each subject was determined by surrogate data analysis. The method was tested in control conditions as well as in two different experimental conditions; with and without use of mild mechanosensory intervention. RESULTS: Our multivariate analysis revealed a significantly higher coherence, as confirmed by surrogate data analysis, in the frequency range associated with eupneic breathing compared to the other ranges. CONCLUSIONS: Our analysis validates the models behind our new approaches, and our results confirm the presence of cardio-respiratory coupling in early stages of development, particularly during periods of mild mechanosensory intervention, thus encouraging further application of our approach.