1. Neonatal respiratory control
- Author
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Rossor, Thomas Edward, Rafferty, Gerrard Francis, and Greenough, Anne
- Subjects
618.92 - Abstract
Background: Disruption of the development of a stable and responsive system of respiratory control may be central to neonatal apnoea and Sudden Infant Death Syndrome. Aims: To test the hypotheses that sleeping position, maternal smoking and substance misuse will alter the ventilatory responses to hypercarbia and hypoxia in term infants; prematurely born infants with a lower ventilatory response to hypercarbia are at greater risk of developing apnoea, caffeine will increase this response; management of gastro-oesophageal reflux varies between NICUs, investigations that detect non-acid reflux will be more sensitive in diagnosing GORD, apnoea frequency will be greater following reflux events than before. Methods: The hypoxic and hypercarbic ventilatory responses were measured in term infants. The ventilatory response to hypercarbia was measured in preterm infants soon after birth and weekly until discharge. A survey was sent to UK NICUs. Infants on the NICU were investigated with pH/MII and polysomnography. Results of Upper gastro-intestinal contrast studies were compared with the results of pH/MII study. Results: Maternal substance misuse alters breathing characteristics and response to hypoxia in newborns. In these infants prone compared to supine sleeping is associated with a lower minute volume. In prematurely born infants, a lower ventilatory response to hypercarbia predicted those that would develop apnoea. Caffeine was associated with an increased ventilatory response to hypercarbia. Investigation and management of gastro-oesophageal reflux in NICUs varies widely. pH/MII increases the detection of reflux events compared to pH alone. The results of pH/MII and upper gastro-intestinal contrast study correlate poorly. Apnoea frequency is no greater following reflux than preceding, or during reflux free periods. Conclusion: Risks factors for SIDS alter respiratory control; apnoea of prematurity is associated with a reduced response to hypercarbia, which is increased by caffeine; there is little evidence for a role of gastro-oesophageal reflux in the pathogenesis of apnoea.
- Published
- 2018