title: Assessment of effect of nasal continuous positive pressure on laryngeal opening using fibre optic laryngoscopy.
abstract: OBJECTIVE
  To assess the effect of nasal continuous positive airways pressure (CPAP) on the dimensions of the laryngeal opening.
  
  
  METHODS
  Nine preterm infants who had previously received ventilatory support for respiratory distress syndrome (RDS) were studied. All were receiving nasal CPAP. The laryngeal opening was visualised using a fibre optic video camera system. The ratio of width to length of the opening was measured on and off CPAP.
  
  
  RESULTS
  In eight of the infants the width: length ratio increased on CPAP; mean change for group +24.4% (95% CI +11.9 to +37.9).
  
  
  CONCLUSIONS
  Nasal CPAP seems to dilate the larynx. This may explain the selective beneficial effects of CPAP on mixed and obstructive apnoea.
authors.affiliation: Department of Paediatrics, United Medical and Dental School of Guy's and St Thomas' Hospital, London SE1 7EH.
authors.forename: P
authors.initials: P
authors.lastname: Gaon
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: S
authors.initials: S
authors.lastname: Hannan
authors.forename: D
authors.initials: D
authors.lastname: Ingram
authors.forename: A D
authors.initials: AD
authors.lastname: Milner
mesh_terms: D001049:Apnea / Q000517:prevention & control*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007830:Larynx / Q000033:anatomy & histology*; D011175:Positive-Pressure Respiration