title: Objective analysis of voice changes in a hemodialysis session and its correlation with ultrafiltration.
abstract: BACKGROUND
  The aim of the study is to analyze the voice changes occurring during a hemodialysis session objectively and to investigate the statistical correlation between voice changes and ultrafiltration, blood pressure, dry weight and the other variables of the patients.
  
  
  METHODS
  A total of 169 patients were included in the study. Electronic voice recordings of the patients were performed with the aim of making objective voice analysis before and after dialysis. Fundamental frequency measurements occurring at the level of the larynx (Fo) and harmonic-to-noise ratio (HNR) were measured from these voice recordings.
  
  
  RESULTS
  When the voice recordings obtained from 169 hemodialysis patients before and after dialysis were investigated, it was observed that a significant increase occurred in the Fo (from 164.52±43.36 Hz to 193.19±47.08 Hz, p<0.01). When the change in HNR was investigated, a significant reduction was determined in the post-dialysis measurements (4.6±3.23 dB) compared to the pre-dialysis measurements (16.10±4.06 dB, p<0.01). Mean 2.49±0.83 L of ultrafiltration was performed and a significant reduction was observed in post-session body weights of the patients (p<0.01). There was a highly statistical significance between the measurements of post-dialysis Fo and post-dialysis body weights. A highly significant correlation was determined between the amount of ultrafiltration performed and a significant increase observed in Fo before and after dialysis. Also a significant correlation was determined between the reduction in the mean post-session blood pressures and the reduction in the HNRs.
  
  
  CONCLUSIONS
  Objective voice analysis is suggesting that it can be a simple and applicable method that can be used to determine the dry weight.
authors.affiliation: Department of Dialysis, Health Services Vocational School of Higher Education, Istanbul Aydin University , Istanbul , Turkey .
authors.forename: Suat
authors.initials: S
authors.lastname: Unver
authors.forename: Umit
authors.initials: U
authors.lastname: Hardal
authors.forename: Kenan
authors.initials: K
authors.lastname: Esertas
authors.forename: Adem
authors.initials: A
authors.lastname: Sezen
authors.forename: Fatma
authors.initials: F
authors.lastname: Celikbilek
authors.forename: Aytug
authors.initials: A
authors.lastname: Altundag
mesh_terms: D000328:Adult; D000368:Aged; D001795:Blood Pressure Determination; D001835:Body Weight; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D013018:Sound Spectrography; D013068:Speech Production Measurement; D013223:Statistics as Topic; D014421:Turkey; D014462:Ultrafiltration / Q000009:adverse effects / Q000379:methods; D014832:Voice Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D014833:Voice Quality / Q000502:physiology*
keywords: Dry weight; hemodialysis; objective voice analysis; ultrafiltration