title: Effects of Moderate Hyperbilirubinemia on Nutritive Swallowing and Swallowing-Breathing Coordination in Preterm Lambs.
abstract: BACKGROUND
  Hyperbilirubinemia (HB) occurs in 90% of preterm newborns. HB induces acute neurological disorders (somnolence, abnormal tone, feeding difficulties, auditory dysfunction) and alterations in respiratory control. These findings suggest brainstem neurotoxicity that could also affect swallowing centers.
  
  
  OBJECTIVE
  To test the hypothesis that HB impairs nutritive swallowing (NS) and swallowing-breathing coordination.
  
  
  METHODS
  Two groups of preterm lambs (born 14 days prior to term), namely control (n = 6) and HB (n = 5), were studied. On day 5 of life (D0), moderate HB (150-250 µmol/l) was induced during 17 h in the HB group. Swallowing was assessed via recording of pharyngeal pressure and respiration by respiratory inductance plethysmography and pulse oximetry. The effect of HB on NS was assessed during standardized bottle-feeding. A second recording was performed 48 h after recovery from HB (D3).
  
  
  RESULTS
  Swallows were less frequent (p = 0.003) and of smaller volume (p = 0.01) in HB lambs while swallowing frequency was decreased (p = 0.004). These differences disappeared after HB normalization. Swallowing-breathing coordination was impaired in HB lambs, with a decrease in percent time with NS burst-related apneas/hypopneas at D0 and D3. Simultaneously, HB lambs tended to experience more severe desaturations (<80%) during bottle-feeding. Finally, following bottle-feeding, the respiratory rate was significantly lower, along with an increased apnea duration in HB lambs.
  
  
  CONCLUSIONS
  Swallowing and swallowing-breathing coordination are altered by acute moderate HB in preterm lambs. Decreased efficiency at bottle-feeding is accompanied by continuation of breathing during swallow bursts, which may promote lung aspiration.
authors.affiliation: Respiratory Physiology Department, CHU de Poitiers, Faculté de Médecine et de Pharmacie, Université de Poitiers, Poitiers, France.
authors.forename: Mélisande
authors.initials: M
authors.lastname: Bourgoin-Heck
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Specq
authors.forename: Nathalie
authors.initials: N
authors.lastname: Samson
authors.forename: Charlène
authors.initials: C
authors.lastname: Nadeau
authors.forename: Martin
authors.initials: M
authors.lastname: Prodel
authors.forename: François
authors.initials: F
authors.lastname: Corbin
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Praud
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001049:Apnea / Q000503:physiopathology*; D001903:Bottle Feeding; D003679:Deglutition; D005260:Female; D006932:Hyperbilirubinemia / Q000503:physiopathology*; D008297:Male; D010991:Plethysmography; D012119:Respiration; D012756:Sheep