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ADC-FNN Online First, published on July 26, 2017 as 10.1136/archdischild-2016-312471 Original article
Cerebral oxygenation during skin-to-skin care in preterm infants not receiving respiratory support Laila Lorenz,1,2 Adriana Marulli,1,3 Jennifer A Dawson,1,3,4 Louise S Owen,1,3,4 Brett J Manley,1,3 Susan M Donath,3,4 Peter G Davis,1,3,4 C Omar F Kamlin1,3,4 1
Newborn Research Centre and Neonatal Services, The Royal Women's Hospital, Melbourne, Australia 2 Department of Neonatology, University Children's Hospital of Tübingen, Tübingen, Germany 3 University of Melbourne, Melbourne, Australia 4 Murdoch Childrens Research Institute, Melbourne, Australia Correspondence to Dr Laila Lorenz, Newborn Research Centre, The Royal Women's Hospital, Locked Bag 300, Grattan St & Flemington Road, Parkville VIC 3052, Australia; laila.lorenz@ thewomens.org.au Received 6 December 2016 Revised 19 May 2017 Accepted 20 May 2017
ABSTRACT Objective Skin-to-skin care (SSC) has proven benefits in preterm infants, but increased hypoxic and bradycardic events have been reported. This may make clinicians hesitant to recommend SSC as standard care. We hypothesised that regional cerebral oxygenation (rStO2) measured with near infrared spectroscopy is not worse during SSC compared with standard incubator care. Design Prospective, observational, non-inferiority study. Setting Single tertiary perinatal centre in Australia. Patients Forty preterm infants (median (IQR) 30.6 (29.1–31.7) weeks’ gestation) not receiving respiratory support were studied on day 14 (8–38). Interventions Recordings during 90 min of incubator care, followed by 90 min of SSC. Each infant acted as their own control and caregivers were blinded to the rStO2 measurements. Main outcome measures The primary outcome was the mean difference in rStO2 between SSC and incubator care. The prespecified margin of non-inferiority was −1.5%. Secondary outcomes included heart rate (HR), peripheral oxygen saturation (SpO2), time in quiet sleep, temperature and hypoxic (SpO2 5 s) or bradycardic events (HR5 s) and time spent in cerebral hypoxia (rStO285%). Results Mean (SD) rStO2 was lower during SSC compared with incubator care: 73.6 (6.0)% vs 74.8 (4.6)%, mean difference (95% CI) −1.3 (−2.2 to −0.4)%. HR was 5 bpm higher, SpO2 1% lower and time in quiet sleep 24% longer during SSC. Little evidence of a difference was observed in temperature. The number of hypoxic or bradycardic events as well as the proportion of time spent in cerebral hypoxia and hyperoxia was very low in both periods. Conclusions Mean rStO2 was marginally lower during SSC without observed differences in hypoxic or bardycardic events but an increase in time spent in quiet sleep. Trial registration number This trial is linked to Australian New Zealand Clinical Trials Registry: identifier 12616000240448. It was registered pre-results.
Background To cite: Lorenz L, Marulli A, Dawson JA, et al. Arch Dis Child Fetal Neonatal Ed Published Online First: [please include Day Month Year]. doi:10.1136/ archdischild-2016-312471
Kangaroo mother care was developed in 1978 as an intervention to address high rates of preterm infant mortality in an under-resourced hospital in Bogota, Colombia.1 Since then, the practice has been adapted to meet specific clinical needs and intermittent skin-to-skin care (SSC) is practised in conjunction with modern technology in neonatal intensive care units.2 SSC is defined as the prone placement
What is already known on this topic? ►► Bradycardic and hypoxic events can occur
during skin-to-skin care (SSC) potentially creating a barrier to its routine practice in very preterm infants. ►► Near infrared spectroscopy measures brain oxygenation and could help avoid the burden of hypoxia and hyperoxia. ►► Cerebral hypoxia and hyperoxia might contribute
to long-term morbidity in preterm infants.
What this study adds? ►► SSC leads to a reduction in rStO2 of about 1%
which is unlikely to be of clinical importance.
►► SSC does not lead to an increased number of
bradycardic and hypoxic events or a longer time spent in cerebral hyperoxia and hypoxia.
►► The change in position of the infant (from supine
to prone) and the angle on mother/father’s chest during SSC does not influence cerebral oxygenation.
of a nappy-clad infant in direct skin contact with their mother’s or father’s chest. There are many proven benefits of SSC to the preterm infant. It reduces mortality, decreases the risk of sepsis and increases exclusive breast feeding.3 4 The majority of these effects, however, were seen in studies conducted in low-income countries.5 6 Conversely, there are also reports of physiological instability during SSC. Bohnhorst et al showed an increased number of hypoxic and bradycardic events during SSC compared with incubator care,7 8 which may be a barrier to its widespread implementation, especially in preterm infants.9 Insufficient oxygen supply to the brain might contribute to morbidity and mortality in preterm infants.10 Monitoring regional cerebral oxygenation (rStO2) measured non-invasively by near-infrared spectroscopy (NIRS), which serves as a surrogate measure of brain oxygen supply and consumption, may be beneficial. NIRS uses light in the near infrared range (700–1000 nm) that penetrates tissue to a depth of 1–2 cm, and relies on the differential absorption capacities of oxygenated and deoxygenated haemoglobin.11 12 In the neonatal intensive care unit, NIRS is most commonly used as a research tool.13–15 Evidence suggests that the
Lorenz L, et al. Arch Dis Child Fetal Neonatal Ed 2017;0:1–6. doi:10.1136/archdischild-2016-312471
F1
Copyright Article author (or their employer) 2017. Produced by BMJ Publishing Group Ltd (& RCPCH) under licence.
Downloaded from http://fn.bmj.com/ on July 28, 2017 - Published by group.bmj.com
Original article burden of hyperoxia and hypoxia can be avoided by monitoring brain oxygenation using NIRS,16 but its long-term benefits are still unknown. There is a paucity of data regarding infant physiological stability during SSC especially in very preterm infants.9 If rStO2 is not reduced during SSC, compared with incubator care, this would provide reassurance regarding physiological stability during SSC. Therefore, our aim was to compare rStO2 and other physiological parameters during SSC with incubator care in very preterm infants.
Study outcomes
The primary outcome was the difference between each infant’s mean rStO2 during SSC compared with their rStO2 during incubator care. Secondary outcomes were HR, SpO2, cFTOE, variability in rStO2, proportion of time spent in cerebral hypoxia and hyperoxia, number of hypoxic and bradycardic events, proportion of time spent in quiet sleep and axillary temperature.
Study design and intervention
Infants were eligible for inclusion if they were born
ADC-FNN Online First, published on July 26, 2017 as 10.1136/archdischild-2016-312471 Original article
Cerebral oxygenation during skin-to-skin care in preterm infants not receiving respiratory support Laila Lorenz,1,2 Adriana Marulli,1,3 Jennifer A Dawson,1,3,4 Louise S Owen,1,3,4 Brett J Manley,1,3 Susan M Donath,3,4 Peter G Davis,1,3,4 C Omar F Kamlin1,3,4 1
Newborn Research Centre and Neonatal Services, The Royal Women's Hospital, Melbourne, Australia 2 Department of Neonatology, University Children's Hospital of Tübingen, Tübingen, Germany 3 University of Melbourne, Melbourne, Australia 4 Murdoch Childrens Research Institute, Melbourne, Australia Correspondence to Dr Laila Lorenz, Newborn Research Centre, The Royal Women's Hospital, Locked Bag 300, Grattan St & Flemington Road, Parkville VIC 3052, Australia; laila.lorenz@ thewomens.org.au Received 6 December 2016 Revised 19 May 2017 Accepted 20 May 2017
ABSTRACT Objective Skin-to-skin care (SSC) has proven benefits in preterm infants, but increased hypoxic and bradycardic events have been reported. This may make clinicians hesitant to recommend SSC as standard care. We hypothesised that regional cerebral oxygenation (rStO2) measured with near infrared spectroscopy is not worse during SSC compared with standard incubator care. Design Prospective, observational, non-inferiority study. Setting Single tertiary perinatal centre in Australia. Patients Forty preterm infants (median (IQR) 30.6 (29.1–31.7) weeks’ gestation) not receiving respiratory support were studied on day 14 (8–38). Interventions Recordings during 90 min of incubator care, followed by 90 min of SSC. Each infant acted as their own control and caregivers were blinded to the rStO2 measurements. Main outcome measures The primary outcome was the mean difference in rStO2 between SSC and incubator care. The prespecified margin of non-inferiority was −1.5%. Secondary outcomes included heart rate (HR), peripheral oxygen saturation (SpO2), time in quiet sleep, temperature and hypoxic (SpO2 5 s) or bradycardic events (HR5 s) and time spent in cerebral hypoxia (rStO285%). Results Mean (SD) rStO2 was lower during SSC compared with incubator care: 73.6 (6.0)% vs 74.8 (4.6)%, mean difference (95% CI) −1.3 (−2.2 to −0.4)%. HR was 5 bpm higher, SpO2 1% lower and time in quiet sleep 24% longer during SSC. Little evidence of a difference was observed in temperature. The number of hypoxic or bradycardic events as well as the proportion of time spent in cerebral hypoxia and hyperoxia was very low in both periods. Conclusions Mean rStO2 was marginally lower during SSC without observed differences in hypoxic or bardycardic events but an increase in time spent in quiet sleep. Trial registration number This trial is linked to Australian New Zealand Clinical Trials Registry: identifier 12616000240448. It was registered pre-results.
Background To cite: Lorenz L, Marulli A, Dawson JA, et al. Arch Dis Child Fetal Neonatal Ed Published Online First: [please include Day Month Year]. doi:10.1136/ archdischild-2016-312471
Kangaroo mother care was developed in 1978 as an intervention to address high rates of preterm infant mortality in an under-resourced hospital in Bogota, Colombia.1 Since then, the practice has been adapted to meet specific clinical needs and intermittent skin-to-skin care (SSC) is practised in conjunction with modern technology in neonatal intensive care units.2 SSC is defined as the prone placement
What is already known on this topic? ►► Bradycardic and hypoxic events can occur
during skin-to-skin care (SSC) potentially creating a barrier to its routine practice in very preterm infants. ►► Near infrared spectroscopy measures brain oxygenation and could help avoid the burden of hypoxia and hyperoxia. ►► Cerebral hypoxia and hyperoxia might contribute
to long-term morbidity in preterm infants.
What this study adds? ►► SSC leads to a reduction in rStO2 of about 1%
which is unlikely to be of clinical importance.
►► SSC does not lead to an increased number of
bradycardic and hypoxic events or a longer time spent in cerebral hyperoxia and hypoxia.
►► The change in position of the infant (from supine
to prone) and the angle on mother/father’s chest during SSC does not influence cerebral oxygenation.
of a nappy-clad infant in direct skin contact with their mother’s or father’s chest. There are many proven benefits of SSC to the preterm infant. It reduces mortality, decreases the risk of sepsis and increases exclusive breast feeding.3 4 The majority of these effects, however, were seen in studies conducted in low-income countries.5 6 Conversely, there are also reports of physiological instability during SSC. Bohnhorst et al showed an increased number of hypoxic and bradycardic events during SSC compared with incubator care,7 8 which may be a barrier to its widespread implementation, especially in preterm infants.9 Insufficient oxygen supply to the brain might contribute to morbidity and mortality in preterm infants.10 Monitoring regional cerebral oxygenation (rStO2) measured non-invasively by near-infrared spectroscopy (NIRS), which serves as a surrogate measure of brain oxygen supply and consumption, may be beneficial. NIRS uses light in the near infrared range (700–1000 nm) that penetrates tissue to a depth of 1–2 cm, and relies on the differential absorption capacities of oxygenated and deoxygenated haemoglobin.11 12 In the neonatal intensive care unit, NIRS is most commonly used as a research tool.13–15 Evidence suggests that the
Lorenz L, et al. Arch Dis Child Fetal Neonatal Ed 2017;0:1–6. doi:10.1136/archdischild-2016-312471
F1
Copyright Article author (or their employer) 2017. Produced by BMJ Publishing Group Ltd (& RCPCH) under licence.
Downloaded from http://fn.bmj.com/ on July 28, 2017 - Published by group.bmj.com
Original article burden of hyperoxia and hypoxia can be avoided by monitoring brain oxygenation using NIRS,16 but its long-term benefits are still unknown. There is a paucity of data regarding infant physiological stability during SSC especially in very preterm infants.9 If rStO2 is not reduced during SSC, compared with incubator care, this would provide reassurance regarding physiological stability during SSC. Therefore, our aim was to compare rStO2 and other physiological parameters during SSC with incubator care in very preterm infants.
Study outcomes
The primary outcome was the difference between each infant’s mean rStO2 during SSC compared with their rStO2 during incubator care. Secondary outcomes were HR, SpO2, cFTOE, variability in rStO2, proportion of time spent in cerebral hypoxia and hyperoxia, number of hypoxic and bradycardic events, proportion of time spent in quiet sleep and axillary temperature.
Study design and intervention
Infants were eligible for inclusion if they were born
