title: Night-to-night variation of pulse oximetry in children with sleep-disordered breathing.
abstract: BACKGROUND
  Sleep-disordered breathing is a common and serious feature of many paediatric conditions and is particularly a problem in children with Down syndrome. Overnight pulse oximetry is recommended as an initial screening test, but it is unclear how overnight oximetry results should be interpreted and how many nights should be recorded.
  
  
  METHODS
  This retrospective observational study evaluated night-to-night variation using statistical measures of repeatability for 214 children referred to a paediatric respiratory clinic, who required overnight oximetry measurements. This included 30 children with Down syndrome. We measured length of adequate trace, basal SpO2, number of desaturations (>4% SpO2drop for >10 s) per hour ('adjusted index') and time with SpO2<90%. We classified oximetry traces into normal or abnormal based on physiology.
  
  
  RESULTS
  132 out of 214 (62%) children had three technically adequate nights' oximetry, including 13 out of 30 (43%) children with Down syndrome. Intraclass correlation coefficient for adjusted index was 0.54 (95% CI 0.20 to 0.81) among children with Down syndrome and 0.88 (95% CI 0.84 to 0.91) for children with other diagnoses. Negative predictor value of a negative first night predicting two subsequent negative nights was 0.2 in children with Down syndrome and 0.55 in children with other diagnoses.
  
  
  CONCLUSIONS
  There is substantial night-to-night variation in overnight oximetry readings among children in all clinical groups undergoing overnight oximetry. This is a more pronounced problem in children with Down syndrome. Increasing the number of attempted nights' recording from one to three provides useful additional clinical information.
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, UK.|Royal Belfast Hospital for Sick Children, Belfast Health & Social Care Trust, Belfast, UK.
authors.forename: Rachael M
authors.initials: RM
authors.lastname: Burke
authors.affiliation: Royal Belfast Hospital for Sick Children, Belfast Health & Social Care Trust, Belfast, UK.
authors.forename: Barbara
authors.initials: B
authors.lastname: Maxwell
authors.affiliation: Royal Belfast Hospital for Sick Children, Belfast Health & Social Care Trust, Belfast, UK.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Hunter
authors.affiliation: Royal Belfast Hospital for Sick Children, Belfast Health & Social Care Trust, Belfast, UK.
authors.forename: David
authors.initials: D
authors.lastname: Graham
authors.affiliation: Royal Belfast Hospital for Sick Children, Belfast Health & Social Care Trust, Belfast, UK.
authors.forename: Dara
authors.initials: D
authors.lastname: O'Donoghue
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, UK.|Royal Belfast Hospital for Sick Children, Belfast Health & Social Care Trust, Belfast, UK.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Shields
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm / Q000502:physiology*; D004314:Down Syndrome / Q000097:blood* / Q000150:complications; D006801:Humans; D007223:Infant; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000150:complications
chemical_list: D010100:Oxygen
keywords: Congenital Abnorm; Neuromuscular; Respiratory; Sleep