title: Children with obstructive sleep-disordered breathing generate high-frequency inspiratory sounds during sleep.
abstract: OBJECTIVE
  We observed that some children with adenotonsillar hypertrophy and obstructive sleep-disordered breathing (SDB) make high-frequency inspiratory sounds (HFIS) during sleep. Our objective was to determine whether HFIS occur in most children with obstructive SDB and adenotonsillar hypertrophy and whether adenotonsillectomy reduces HFIS.
  
  
  METHODS
  Prospective consecutive-entry trial.
  
  
  METHODS
  Sleep laboratory.
  
  
  METHODS
  Twenty-six children between 6 and 12 years of age with adenotonsillar hypertrophy suspected of having obstructive SDB.
  
  
  RESULTS
  We performed polysomnography and measured sounds during sleep with a microphone suspended above the bed. Sounds were recorded on a computer at 44 kHz, analyzed with fast Fourier transformation for frequency content. HFIS were sounds occurring during an inspiration with frequencies greater than 2 kHz. HFIS were different from the low-frequency (< 2 kHz) sounds described in snoring adults. HFIS usually occurred in consecutive breaths, occasionally exceeding 100. We counted the number of HFIS that occurred per hour of sleep. Children who made more HFIS had more obstructive SDB than did those who did not make the HFIS, and there was a significant positive correlation between the number of HFIS and the obstructive apnea-hypopnea index. Children with more than 3 apneas and hypopneas per hour of sleep all made at least 10 HFIS per hour, and all children who had more than 10 HFIS per hour had obstructive apnea-hypopnea index values greater than 1. Children with adenotonsillar hypertrophy made more HFIS than did those children whose tonsils and adenoids had been removed.
  
  
  CONCLUSIONS
  HFIS may be a marker of disturbed breathing during sleep in children with adenotonsillar hypertrophy.
authors.affiliation: Cardiovascular Division, Department of Internal Medicine and Physiology, University of Virginia Health System, Charlottesville, VA 22908-1395, USA. crembold@virginia.edu
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Rembold
authors.forename: Paul M
authors.initials: PM
authors.lastname: Suratt
mesh_terms: D000233:Adenoidectomy; D000234:Adenoids / Q000473:pathology / Q000601:surgery; D015992:Body Mass Index; D002648:Child; D004576:Electromyography; D004585:Electrooculography; D005260:Female; D006801:Humans; D006984:Hypertrophy / Q000453:epidemiology / Q000473:pathology; D008297:Male; D014066:Palatine Tonsil / Q000473:pathology / Q000601:surgery; D017286:Polysomnography; D011446:Prospective Studies; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000453:epidemiology*; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology*; D012894:Sleep Stages / Q000502:physiology; D012913:Snoring / Q000453:epidemiology*; D014068:Tonsillectomy