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ADC-FNN Online First, published on July 26, 2017 as 10.1136/archdischild-2016-311769 Original article

Changes in cardiac output and cerebral oxygenation during prone and supine sleep positioning in healthy term infants Tai-Wei Wu,1,2 Rey-In Lien,3 Istvan Seri,2 Shahab Noori1,2 1

Abstract Objective  To investigate the changes in systemic and cerebral haemodynamics between supine and prone sleep in healthy term infants during the early postnatal period. Design/methods  Healthy term infants without congenital anomalies, patent ductus arteriosus and/or small for gestational age status were enrolled. Infants were placed in supine (SP1), prone (PP) and back in supine (SP2) position for 15 min each while asleep. Cardiac output Correspondence to (CO) and stroke volume (SV) were assessed by electrical Dr Tai-Wei Wu, Division of velocimetry (EV) and echocardiography (echo), and cerebral Neonatology, Fetal and regional oxygen saturation (CrSO2) in the frontal lobes was Neonatal Institute, Children’s monitored by near-infrared spectroscopy. Heart rate (HR) Hospital Los Angeles, 4650 and SpO2 were continuously monitored by conventional Sunset Blvd; MS #31 Los Angeles, CA 90027, USA; ​twu@​ monitoring. chla.u​ sc.​edu Results  In 34 healthy term infants (mean age 3.7±1.2 days; 16 females), 66 sets of serial CO measurements Received 5 August 2016 (34 EV and 32 echo) in three sleep positions were Revised 4 April 2017 Accepted 2 May 2017 obtained. Mean COEV and COecho were 182±57 (SP1), 170±50 (PP) and 177±54 (SP2), and 193±48 (SP1), 174±40 (PP) and 192±50 (SP2) mL/kg/min, respectively. Mean SVEV and SVecho were 1.46±0.47 (SP1), 1.36±0.38 (PP) and 1.37±0.39 (SP2), and 1.54±40 (SP1), 1.38±0.38 (PP) and 1.51±0.41 (SP2) mL/kg, respectively. Repeated measures analysis of variance revealed a decrease in CO and SV during prone positions by both EV and echo, while HR, SpO2 and CrSO2 did not change. Thirty-eight per cent of the CO measurements decreased ≥10% during prone positioning. Conclusions  In healthy term infants, CO decreases in prone position due to a decrease in SV and not HR. CO recovers when placed back in supine. However, frontal lobe CrSO2 does not change in the different positions.

Division of Neonatology, Fetal and Neonatal Institute, Children’s Hospital Los Angeles, Los Angeles, California, USA 2 Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA 3 Department of Pediatrics, Chang Gung Children’s Hospital, Taoyuan, Taiwan

Background

To cite: Wu T-W, Lien R-I, Seri I, et al. Arch Dis Child Fetal Neonatal Ed Published Online First: [please include Day Month Year]. doi:10.1136/ archdischild-2016-311769

Sudden infant death syndrome (SIDS) continues to be the leading cause of death in children between 1  month and 1  year of age.1 In 2015, about 1600 infants died of SIDS in the USA.2 Although the Back to Sleep campaign has reduced the incidence of SIDS by more than 50%, the exact mechanism(s) by which prone sleep position (PP) contributes to SIDS risk remains unclear.1 3 There is a growing body of evidence that sleep position can alter an infant’s cerebrovascular control, even in a healthy term infant. Cerebral tissue oxygenation index is depressed in PP and the magnitude of decrease is more pronounced at 2–3 months of age, a time period in development when the SIDS incidence peaks.4 Importantly, PP induces cardiovascular

What is already known on this topic? ►► Prone sleep positioning is a major risk factor

for sudden infant death syndrome. Prone positioning induces haemodynamic changes in adults and children, altering heart rate, baroreflex, blood pressure and cerebral tissue oxygenation.

►► In late preterm infants, cardiac output is lower in

the prone compared with supine position.

What this study adds? ►► In healthy term infants, prone sleep positioning

can cause a decrease in cardiac output, due to a decrease in stroke volume and not heart rate.

►► However, regional cerebral oxygenation remained

unchanged even in infants who had a significant decrease in cardiac output. changes in infants, including chronological age-dependent changes in blood pressure (BP), baroreflex control 4–6 and a minimal increase in heart rate (HR).4 In healthy adults, cardiac MRI detected an 8%–9%  decrease in stroke volume (SV) and cardiac output (CO) in PP compared with supine position (SP).7 8 We have recently reported similar findings in late preterm infants in the intensive care setting at around 36 weeks’ postmenstrual age. Using electrical velocimetry (EV) and laser Doppler to estimate CO and skin perfusion, respectively, we found that PP, compared with SP, is associated with a significant reduction in CO, SV and skin perfusion, and a concomitant increase in calculated systemic vascular resistance (SVR).9 However, it is unclear if the reduction in SV is secondary to changes in preload, afterload and/or contractility. Changes in CO have not been systematically studied in healthy term infants in different sleep positions. CO  can be non-invasively assessed by EV,10 echocardiography (echo) or cardiac MRI.11 However, there are technical difficulties in the assessment of CO in PP. It is unclear if PP alters the chest wall electrical impedance, which is an important variable in the algorithmic calculation of CO when EV is being used. Echo  is not usually performed in PP, unless it is by the transoesophageal route. Cardiac MRI is becoming the new gold standard for CO measurements, but is limited by logistic difficulties in clinical studies that require

Wu T-W, et al. Arch Dis Child Fetal Neonatal Ed 2017;0:1–7. doi:10.1136/archdischild-2016-311769

   F1

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Original article haemodynamic trending. In this study, we used two non-invasive methods of CO assessment, EV (COEV) and echocardiography (COecho), to evaluate changes in CO, SV and HR during sleep positional changes. Furthermore, we investigated whether cerebral oxygenation is affected if there is a positioning-associated alteration in CO . Accordingly, this study aims to assess the changes in CO, SV, HR and cerebral regional oxygen saturation (CrSO2) in relation to changes in sleep position in healthy term infants during the first week after birth. We hypothesise that prone positioning will decrease CO and CrSO2 in healthy term infants during the first postnatal week.

Methods Subjects

Thirty-four healthy term newborns delivered at the Chang Gung Memorial Hospital, Taoyuan, Taiwan, were prospectively enrolled into the study within the first week of life, between August 2014 and November 2015. Exclusion criteria included prematurity, respiratory distress, congenital anomalies and small for gestational age (

Changes in cardiac output and cerebral oxygenation during prone and supine sleep positioning in healthy term infants.

To investigate the changes in systemic and cerebral haemodynamics between supine and prone sleep in healthy term infants during the early postnatal pe...
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