Prone sleeping affects cardiovascular control in preterm infants in NICU.

BACKGROUND: Prone sleeping is used in preterm infants undergoing intensive care to improve respiratory function, but evidence suggests that this position may compromise autonomic cardiovascular control. To test this hypothesis, this study assessed the effects of the prone sleeping position on cardiovascular control in preterm infants undergoing intensive care treatment during early postnatal life. METHODS: Fifty-six preterm infants, divided into extremely preterm (gestational age (GA) 24-28 weeks, n = 23) and very preterm (GA 29-34 weeks, n = 33) groups, were studied weekly for 3 weeks in prone and supine positions, during quiet and active sleep. Heart rate (HR) and non-invasive blood pressure (BP) were recorded and autonomic measures of HR variability (HRV), BP variability (BPV), and baroreflex sensitivity (BRS) using frequency analysis in low (LF) and high (HF) bands were assessed. RESULTS: During the first 3 weeks, prone sleeping increased HR, reduced BRS, and increased HF BPV compared to supine. LF and HF HRV were also lower prone compared to supine in very preterm infants. Extremely preterm infants had the lowest HRV and BRS measures, and the highest HF BPV. CONCLUSIONS: Prone sleeping dampens cardiovascular control in early postnatal life in preterm infants, having potential implications for BP regulation in infants undergoing intensive care.

Effects of Prone Sleeping on Cerebral Oxygenation in Preterm Infants.

OBJECTIVE: To determine the effect of prone sleeping on cerebral oxygenation in preterm infants in the neonatal intensive care unit. STUDY DESIGN: Preterm infants, divided into extremely preterm (gestational age 24-28 weeks; n = 23) and very preterm (gestational age 29-34 weeks; n = 33) groups, were studied weekly until discharge in prone and supine positions during active and quiet sleep. Cerebral tissue oxygenation index (TOI) and arterial oxygen saturation (SaO2) were recorded. Cerebral fractional tissue extraction (CFOE) was calculated as CFOE = (SaO2 - TOI)/SaO2. RESULTS: In extremely preterm infants, CFOE increased modestly in the prone position in both sleep states at age 1 week, in no change in TOI despite higher SaO2. In contrast, the very preterm infants did not have position-related differences in CFOE until the fifth week of life. In the very preterm infants, TOI decreased and CFOE increased with active sleep compared with quiet sleep and with increasing postnatal age. CONCLUSION: At 1 week of age, prone sleeping increased CFOE in extremely preterm infants, suggesting reduced cerebral blood flow. Our findings reveal important physiological insights in clinically stable preterm infants. Further studies are needed to verify our findings in unstable preterm infants regarding the potential risk of cerebral injury in the prone sleeping position in early postnatal life.

Insights into the effects of sleep disordered breathing on the brain in infants and children: Imaging and cerebral oxygenation measurements.

Sleep disordered breathing (SDB) is a common condition in infants and children. SDB encompasses a spectrum of respiratory disorders, which are defined as either obstructive or central in nature. Obstructive SDB ranges in severity from primary snoring (PS), to obstructive sleep apnea (OSA). There are a number of conditions characterized by central sleep apnea (CSA), including but not limited to periodic breathing in infants, Arnold Chiari malformations, and idiopathic CSA. SDB is associated with adverse cardiovascular and neurocognitive outcomes believed to be the consequence of the repeated cycles of hypoxia followed by reperfusion, hypercarbia, and sleep fragmentation. The peripheral hypoxia in individuals with SDB may not reflect cerebral oxygenation, and near infrared spectroscopy (NIRS) has been used to determine oxygen delivery and uptake in the brain. Neuroimaging in the form of structural and functional magnetic resonance imaging (MRI, fMRI), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS) have become widely used to determine the structural, functional and chemical changes in the brain associated with SDB. This review will explore the relationship between central and obstructive SDB and changes in cerebral oxygenation together with changes in brain structure and function, in infants and children. It is important to identify any adverse effects so that they can be mitigated as early as possible to minimize any detrimental effects on the developing brain.

When does prone sleeping improve cardiorespiratory status in preterm infants in the NICU?

STUDY OBJECTIVES: Preterm infants undergoing intensive care are often placed prone to improve respiratory function. Current clinical guidelines recommend preterm infants are slept supine from 32 weeks' postmenstrual age, regardless of gestational age at birth. However, respiratory function is also related to gestational and chronological ages and is affected by sleep state. We aimed to identify the optimal timing for adopting the supine sleeping position in preterm infants, using a longitudinal design assessing the effects of sleep position and state on cardiorespiratory stability. METHODS: Twenty-three extremely (24-28 weeks' gestation) and 33 very preterm (29-34 weeks' gestation) infants were studied weekly from birth until discharge, in both prone and supine positions, in quiet and active sleep determined by behavioral scoring. Bradycardia (heart rate ≤100 bpm), desaturation (oxygen saturation ≤80%), and apnea (pause in respiratory rate ≥10 s) episodes were analyzed. RESULTS: Prone positioning in extremely preterm infants reduced the frequency of bradycardias and desaturations and duration of desaturations. In very preterm infants, prone positioning only reduced the frequency of desaturations. The position-related effects were not related to postmenstrual age. Quiet sleep in both preterm groups was associated with fewer bradycardias and desaturations, and also reduced durations of bradycardia and desaturations in the very preterm group. CONCLUSIONS: Cardiorespiratory stability is improved by the prone sleep position, predominantly in extremely preterm infants, and the improvements are not dependent on postmenstrual age. In very preterm infants, quiet sleep has a more marked effect than the prone position. This evidence should be considered in individualizing management of preterm infant positioning.

Prone sleeping position in infancy: Implications for cardiovascular and cerebrovascular function.

Advances in neonatal care have improved the survival rates of preterm infants, however, the likelihood of brain injury and neurodevelopmental disability remains a significant problem. Whilst the etiology of preterm brain injury is complex, impairments in the cardio- and cerebro-vascular function have been implicated. During infancy, sleep is vital for brain development. However, instabilities in cardio- and cerebro-vascular function are most marked during sleep. Sleeping position is an important part of a safe sleeping environment. Prone sleeping increases the risk of sudden infant death syndrome and is associated with reduced blood pressure, cerebral oxygenation and impaired autonomic cardiovascular control in infants born at term. Importantly, these effects are amplified by preterm birth. Hospitalized preterm infants are often slept in the prone position to improve respiratory function. However, there is little consensus regarding the sustained benefits of prone sleeping in this population. In light of the impaired cardio- and cerebro-vascular function during prone sleeping in term and preterm infants after hospital discharge, the likely adverse effects of prone sleeping in hospitalized preterm infants are concerning. This review examines the cardiovascular and cerebrovascular effects of prone sleeping in infants born at term, those born preterm after term equivalent age and whilst hospitalized.