title: Measurement of Oxygen Desaturation Is Not Useful for the Detection of Aspiration in Dysphagic Stroke Patients.
abstract: BACKGROUND
  Dysphagia is one of the most dangerous symptoms of acute stroke. Various screening tools have been suggested for the early detection of this condition. In spite of conflicting results, measurement of oxygen saturation (SpO2) during clinical swallowing assessment is still recommended by different national guidelines as a screening tool with a decline in SpO2 ≥2% usually being regarded as a marker of aspiration. This paper assesses the sensitivity of SpO2 measurements for the evaluation of aspiration risk in acute stroke patients.
  
  
  METHODS
  Fifty acute stroke patients with moderate to severe dysphagia were included in this study. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardised protocol. Blinded to the results of FEES, SpO2 was monitored simultaneously. The degree of desaturation during/after swallows with aspiration was compared to the degree of desaturation during/after swallows without aspiration in a swallow-to-swallow analysis of each patient. To minimise potential confounders, every patient served as their control.
  
  
  RESULTS
  In each subject, a swallow with and a swallow without aspiration were analysed. Overall, aspiration seen in FEES was related to a minor decline in SpO2 (mean SpO2 without aspiration 95.54 ± 2.7% vs. mean SpO2 with aspiration 95.28 ± 2.7%). However, a significant desaturation ≥2% occurred only in 5 patients during/after aspiration. There was no correlation between aspiration/dysphagia severity or the amount of aspirated material and SpO2 levels.
  
  
  CONCLUSIONS
  According to this study, measurement of oxygen desaturation is not a suitable screening tool for the detection of aspiration in stroke patients.
authors.affiliation: Department of Neurology, University Hospital Münster, Münster, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Marian
authors.forename: Jens
authors.initials: J
authors.lastname: Schröder
authors.forename: Paul
authors.initials: P
authors.lastname: Muhle
authors.forename: Inga
authors.initials: I
authors.lastname: Claus
authors.forename: Stephan
authors.initials: S
authors.lastname: Oelenberg
authors.forename: Christina
authors.initials: C
authors.lastname: Hamacher
authors.forename: Tobias
authors.initials: T
authors.lastname: Warnecke
authors.forename: Sonja
authors.initials: S
authors.lastname: Suntrup-Krüger
authors.forename: Rainer
authors.initials: R
authors.lastname: Dziewas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001785:Blood Gas Monitoring, Transcutaneous; D003679:Deglutition; D003680:Deglutition Disorders / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D063466:Respiratory Aspiration of Gastric Contents / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D010100:Oxygen
keywords: Aspiration; Dysphagic stroke patients; Fiberoptic endoscopic evaluation of swallowing; Oxygen desaturation measurement