title: Upper airway collapsibility during REM sleep in children with the obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  In children, most obstructive events occur during rapid eye movement (REM) sleep. We hypothesized that children with the obstructive sleep apnea syndrome (OSAS), in contrast to age-matched control subjects, would not maintain airflow in the face of an upper airway inspiratory pressure drop during REM sleep.
  
  
  METHODS
  During slow wave sleep (SWS) and REM sleep, we measured airflow, inspiratory time, inspiratory time/total respiratory cycle time, respiratory rate, tidal volume, and minute ventilation at a holding pressure at which flow limitation occurred and at 5 cm H2O below the holding pressure in children with OSAS and in control subjects.
  
  
  METHODS
  Sleep laboratory.
  
  
  METHODS
  Fourteen children with OSAS and 23 normal control subjects.
  
  
  RESULTS
  In both sleep states, control subjects were able to maintain airflow, whereas subjects with OSAS preserved airflow in SWS but had a significant decrease in airflow during REM sleep (change in airflow of 18.58 +/- 12.41 mL/s for control subjects vs -44.33 +/- 14.09 mL/s for children with OSAS, P = 0.002). Although tidal volume decreased, patients with OSAS were able to maintain minute ventilation by increasing the respiratory rate and also had an increase in inspiratory time and inspiratory time per total respiratory cycle time
  
  
  CONCLUSIONS
  Children with OSAS do not maintain airflow in the face of upper-airway inspiratory-pressure drops during REM sleep, indicating a more collapsible upper airway, compared with that of control subjects during REM sleep. However, compensatory mechanisms exist to maintain minute ventilation. Local reflexes, central control mechanisms, or both reflexes and control mechanisms need to be further explored to better understand the pathophysiology of this abnormality and the compensation mechanism.
authors.affiliation: Sleep Center, Children s Hospital of Philadelphia, University of Pennsylvania School ofMedicine, Philadelphia, PA, USA.
authors.forename: Jingtao
authors.initials: J
authors.lastname: Huang
authors.forename: Laurie R
authors.initials: LR
authors.lastname: Karamessinis
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Pepe
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Glinka
authors.forename: John M
authors.initials: JM
authors.lastname: Samuel
authors.forename: Paul R
authors.initials: PR
authors.lastname: Gallagher
authors.forename: Carole L
authors.initials: CL
authors.lastname: Marcus
mesh_terms: D000402:Airway Obstruction / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000150:complications / Q000503:physiopathology; D017286:Polysomnography / Q000379:methods; D012137:Respiratory System / Q000503:physiopathology*; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000503:physiopathology*; D012895:Sleep, REM; D013990:Tidal Volume