title: Tracheal pH monitoring and aspiration in acute stroke.
abstract: BACKGROUND
  aspiration can lead to chest infections, increased morbidity and mortality in stroke sufferers. It is important clinically and for research purposes to identify all patients who aspirate. At present, videofluoroscopy is the gold standard for detecting aspiration. The aim of this study was to investigate aspiration in acute stroke patients, who are safe for oral intake as assessed by bedside swallow test and videofluoroscopy, using tracheal pH monitoring.
  
  
  METHODS
  thirty-four stroke patients admitted to the Acute Stroke Unit gave informed consent and underwent tracheal pH monitoring 4-19 days post-stroke. A standardised acid meal was served.
  
  
  RESULTS
  two traces were discarded. Nine of the 32 remaining studies showed a drop in tracheal pH <5.5 following ingestion of an acidic meal. Two patterns of lowered tracheal pH were observed: three cases showed a prolonged fall in pH to <5.5, which took over 15 minutes to return to baseline and six had acute falls in pH to <5.5, which rapidly recovered in under 4 minutes. In six the drop occurred immediately after the meal, and in three a delay was observed prior to the drop.
  
  
  CONCLUSIONS
  tracheal acidification, which could represent aspiration, has been observed in 9 of 32 stroke patients assessed as safe to take diet and fluids orally by bedside assessment and videofluoroscopy. This is a preliminary investigation that provides information about tracheal pH monitoring in acute stroke patients.
authors.affiliation: Department of Geriatric Medicine, University of Liverpool, Liverpool, Merseyside, UK. Joanne.Clayton@rlbuht.nhs.uk
authors.forename: Joanne
authors.initials: J
authors.lastname: Clayton
authors.forename: Catherine I A
authors.initials: CI
authors.lastname: Jack
authors.forename: Christopher
authors.initials: C
authors.lastname: Ryall
authors.forename: Jane
authors.initials: J
authors.lastname: Tran
authors.forename: Emad
authors.initials: E
authors.lastname: Hilal
authors.forename: Margot
authors.initials: M
authors.lastname: Gosney
mesh_terms: D000208:Acute Disease; D000368:Aged; D003680:Deglutition Disorders / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015994:Incidence; D008297:Male; D011015:Pneumonia, Aspiration / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism; D012307:Risk Factors; D020521:Stroke / Q000150:complications*; D014132:Trachea / Q000378:metabolism*