title: Effects of age and sleeping position on arousal from sleep in preterm infants.
abstract: OBJECTIVE
  Preterm infants are at increased risk of sudden infant death syndrome (SIDS). We investigated whether the prone sleeping position impaired arousal from sleep in healthy preterm infants and whether this impairment was related to cardiorespiratory variables, temperature or postnatal age.
  
  
  METHODS
  Longitudinal
  
  
  METHODS
  14 healthy preterm infants (mean 32 +/- 0.4 weeks) were studied using daytime polysomnography on 4 occasions: 36-38 weeks postconception age, 2 to 3 weeks postterm, 2 to 3 months postterm, and 5 to 6 months postterm.
  
  
  METHODS
  N/A.
  
  
  METHODS
  Multiple measurements of arousal threshold (cm H2O) in response to air-jet stimulation applied alternately to the nares were made in both active sleep and quiet sleep when infants slept both prone and supine.
  
  
  RESULTS
  Arousal thresholds were significantly higher in both AS and QS when infants slept prone at 36 to 38 weeks postconception age and 2 to 3 months postterm but not at 2 to 3 weeks or 5 to 6 months postterm. These increases were independent of any sleep position-related changes in either rectal or abdominal skin temperature, respiratory rate, oxygen saturation or heart rate.
  
  
  CONCLUSIONS
  At the age when the risk of SIDS is highest, the prone position significantly impairs arousal from both active sleep and quiet sleep in healthy infants born prematurely. This impairment in arousability occurred with no clinically significant changes in cardiorespiratory parameters or body temperature. Decreased arousability from sleep in the prone position may explain its role as a risk factor for SIDS.
authors.affiliation: Department of Paediatrics and Ritchie Centre for Baby Health Research, Monash University, Clayton, Victoria, Australia. rosemary.horne@med.monash.edu.au
authors.forename: Rosemary S C
authors.initials: RS
authors.lastname: Horne
authors.forename: Pratiti
authors.initials: P
authors.lastname: Bandopadhayay
authors.forename: Jessica
authors.initials: J
authors.lastname: Vitkovic
authors.forename: Susan M
authors.initials: SM
authors.lastname: Cranage
authors.forename: T Michael
authors.initials: TM
authors.lastname: Adamson
mesh_terms: D001143:Arousal; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008137:Longitudinal Studies; D017286:Polysomnography; D011187:Posture; D016684:Prone Position; D012890:Sleep; D013398:Sudden Infant Death / Q000453:epidemiology