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.

Kangaroo mother care improves cardiorespiratory physiology in preterm infants: an observational study.

OBJECTIVES: To evaluate whether kangaroo mother care (KMC) in preterm infants on non-invasive respiratory support improves indices of cardiorespiratory wellbeing. STUDY DESIGN: Prospective quasi-experimental observational study. SETTING: Tertiary perinatal neonatal unit. PATIENTS: 50 very preterm infants being managed with nasal continuous positive airway pressure. INTERVENTIONS: Continuous high-resolution preductal pulse-oximetry recordings using Masimo Radical-7 oximeter for 1 hour (incubator care) followed by 1 hour during KMC performed on the same day. MAIN OUTCOME MEASURES: Measures of cardiorespiratory stability (dips in oxygen saturations (SpO2)) of ≥5% less than baseline, % time spent with oxygen saturations <90%, SpO2 variability and heart rate fluctuation and incidence of bradycardias. RESULTS: The gestational age and birth weight of the cohort were 28.4±2.1 weeks and 1137±301 g, respectively. Dips in SpO2 of ≥5% less than baseline were significantly fewer with KMC, median (IQR) 24 (12 to 42) vs 13 (3 to 25), p=0.001. SpO2 variability (Delta 12 s and 2 s), (1.24±0.6 vs 0.9±0.4, p=0.005 and 4.1±1.7 vs 2.8±1.2, p<0.0001) and rapid resaturation and desaturation indices were significantly lower during KMC, compared with incubator care. Percentage time spent in oxygen saturations <90% was less with KMC (7.5% vs 2.7%, p=0.04). Mean heart rate was comparable although fluctuations in heart rate (rise by >8 bpm) were lower with KMC (43±22 vs 33±20, p=0.03). Seven (14%) infants had bradycardias during incubator care and none during KMC, p=0.012. CONCLUSIONS: KMC improves cardiorespiratory stability in ventilated preterm infants. Regular KMC has the potential to improve clinical outcomes in this vulnerable cohort.

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.

A randomised crossover trial of clinical algorithm for oxygen saturation targeting in preterm infants with frequent desaturation episodes.

OBJECTIVES: Strategies for oxygen therapy for preterm infants, such as the Vermont-Oxford's 'Breathsavers' guidelines, seek to strike a balance between the potential risks of the extremes of hyperoxia and hypoxia in preterm infants. Using an algorithm based on those guidelines, we aimed to compare the proportion of time spent within the SpO2 target range during algorithm-based management of oxygen delivery compared with routine nursing care. STUDY DESIGN: In a randomised crossover trial, maintenance of SpO2 over a 4-hour period during routine care was compared with algorithm-based control (administered by a dedicated research nurse). SpO2 target (88-92%) and alarm limits (86-94%) were identical in both arms. Infants <32 weeks' gestation were eligible if having >8 desaturations episodes to <85%/4 h while receiving continuous positive airway pressure/synchronised intermittent mandatory ventilation. Data was recorded via the Powerlab system from Masimo oximeters and Babylog 8000+ ventilators. RESULTS: 16 infants with a gestation of 26.7 ± 1.3 weeks (mean ± SD) and birth weight 901 ± 193 g were studied at a postmenstrual age of 30.5 ± 2.4 weeks. The percentage of time spent within target range was 34.6 ± 28.5% during routine care versus 38.3 ± 29.3% during algorithm-based care (p = 0.23). Compliance with alarm limits was 58.4 ± 21.8% during routine versus 64.7 ± 22.1% for algorithm-based care (p = 0.091). The frequency of desaturations, episode severity or number of FiO2 adjustments did not differ between the two care strategies. CONCLUSIONS: The observation that algorithm-based control did not improve time spent within the SpO2 target and alarm limits suggests nursing care has reached an optimum in the unit studied. Our finding indicates that significant modifications to the algorithm are likely to be necessary to improve target range compliance.