title: Overnight pulse oximetry for evaluation of sleep apnea among children with trisomy 21.
abstract: OBJECTIVE
  For children with trisomy 21, polysomnography at age 4 to assess obstructive sleep disordered breathing (OSDB) is the standard of care. Oximetry alone has been used to screen for disease among children without trisomy 21. This study evaluates the potential usefulness of oximetry scoring in diagnosing OSDB among children with trisomy 21.
  
  
  METHODS
  A McGill oximetry score from 1 to 4 was derived from a full overnight PSG done on 119 consecutive pediatric subjects with trisomy 21. Most were referred to the sleep laboratory because of suspicion for OSDB. Oximetry scorers were blinded to the child's full PSG and clinical course. Results of the complete PSG were then compared to oximetry scores.
  
  
  RESULTS
  Obstructive apnea-hypopnea index (OAHI) was ≥ 2.5 for 50% of all subjects. Fifty-nine subjects (49.6%) had McGill Score 1 ("inconclusive"); median OAHI was 1.0 (IQR 0.4-3.3). McGill Score was 2 for 43 subjects (36.1%); median OAHI was 4.5 (IQR 1.3-8.8). Seventeen subjects (14.3%) had McGill Scores of 3 or 4; median OAHI was 16.1 (IQR 9.3-45.5, range 2.1 to 101.1). Ten percent of subjects had a considerable number of central events (≥ 2.5 respiratory events/h but OAHI < 2.5), including 7 with McGill Score 2.
  
  
  CONCLUSIONS
  In a retrospective cohort of children with trisomy 21, McGill oximetry scores of 3 or 4 reliably identified patients with marked OSDB. The possibility of central apneas causing hypoxemia must be considered in those with McGill Score 2. With these caveats, oximetry screening should be considered when developing streamlined protocols for early intervention to treat OSDB in this population.
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Coverstone
authors.affiliation: Sleep Medicine, St. Louis Children's Hospital, St. Louis, MO.
authors.forename: Merielle
authors.initials: M
authors.lastname: Bird
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors.forename: Melissa
authors.initials: M
authors.lastname: Sicard
authors.affiliation: Department of Biostatistics, Washington University School of Medicine, St. Louis, MO.
authors.forename: Yu
authors.initials: Y
authors.lastname: Tao
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors.forename: Dorothy K
authors.initials: DK
authors.lastname: Grange
authors.affiliation: Sleep Medicine, St. Louis Children's Hospital, St. Louis, MO.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cleveland
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, Washington University School of Medicine, St. Louis, MO.
authors.forename: David
authors.initials: D
authors.lastname: Molter
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors.forename: James S
authors.initials: JS
authors.lastname: Kemp
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004314:Down Syndrome / Q000150:complications*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010092:Oximetry / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000175:diagnosis*; D055815:Young Adult
keywords: central apnea; obstructive sleep apnea; pulse oximetry; trisomy 21