title: Non-Invasive detection of respiratory effort-related arousals (REras) by a nasal cannula/pressure transducer system.
abstract: OBJECTIVE
  The published AASM guidelines approve use of a nasal cannula/pressure transducer to detect apneas/hypopneas, but require esophageal manometry for Respiratory Effort-Related Arousals (RERAs). However, esophageal manometry may be poorly tolerated by many subjects. We have shown that the shape of the inspiratory flow signal from a nasal cannula identifies flow limitation and elevated upper-airway resistance. This study tests the hypothesis that detection of flow limitation events using the nasal cannula provides a non-invasive means to identify RERAs.
  
  
  METHODS
  N/A.
  
  
  METHODS
  N/A.
  
  
  METHODS
  10 UARS/OSAS and 5 normal subjects
  
  
  METHODS
  N/A.
  
  
  RESULTS
  All subjects underwent full NPSG. Two scorers identified events from the nasal cannula signal as apneas, hypopneas, and flow limitation events. Two additional scorers identified events from esophageal manometry. Arousals were scored in a separate pass. Interscorer reliability and intersignal agreement were assessed both without and with regard to arousal. The total number of respiratory events identified by the two scorers of the nasal cannula was similar with an Intraclass Correlation (ICC) =0.96, and was essentially identical to the agreement for the two scorers of esophageal manometry (ICC=0.96). There was good agreement between the number of events detected by the two techniques with a slight bias towards the nasal cannula (4.5 events/hr). There was no statistically significant difference (bias 0.9/hr, 95%CI -0.3-2.0) between the number of nasal cannula flow limitation events terminated by arousal and manometry events terminated by arousal (RERAs).
  
  
  CONCLUSIONS
  The nasal cannula/pressure transducer provides a non-invasive reproducible detector of all events in sleep disordered breathing; in particular, it detects the same events as esophageal manometry (RERAs).
authors.affiliation: NYU School of Medicine, New York, NY USA.
authors.forename: I
authors.initials: I
authors.lastname: Ayappa
authors.forename: R G
authors.initials: RG
authors.lastname: Norman
authors.forename: A C
authors.initials: AC
authors.lastname: Krieger
authors.forename: A
authors.initials: A
authors.lastname: Rosen
authors.forename: R L
authors.initials: RL
authors.lastname: O'malley
authors.forename: D M
authors.initials: DM
authors.lastname: Rapoport
mesh_terms: D000328:Adult; D000368:Aged; D001049:Apnea / Q000175:diagnosis; D001143:Arousal / Q000502:physiology*; D002404:Catheterization; D004947:Esophagus / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D009666:Nose; D011312:Pressure; D012119:Respiration; D014159:Transducers