title: Vocal nodules and edema may be due to vibration-induced rises in capillary pressure.
abstract: OBJECTIVE
  Vocal fold vibration may physically raise intravascular pressure to levels high enough to damage capillaries and result in leakage of erythrocytes. This type of injury is commonly seen in benign vocal fold lesions and is not well explained.
  
  
  METHODS
  Theoretical, retrospective.
  
  
  METHODS
  The relationship of intravascular pressure to vibration frequency and amplitude is derived and confirmed with a physical blood vessel model, then applied to published human measurements to estimate human intravascular pressures.
  
  
  RESULTS
  Vocal fold intravascular pressure is predicted to have a quadratic dependence on both frequency and amplitude. During speaking, the pressure may rise to over 20 cmH2O, and may reach levels far higher for screaming and singing. Such pressure magnitudes are known to trigger inflammatory cascades and can lead to fluid leakage. They also have the potential for pharmacologic control with beta-agonists.
  
  
  CONCLUSIONS
  Intravascular pressure likely rises significantly during vocal fold vibration and may lead to the type of injury seen in benign vocal fold lesions. The results support voice therapy aimed at reducing vibratory amplitude. More vibratory amplitude measurements need to be performed in a wider range of subjects before the full range of human vocal fold vascular pressures can be estimated.
authors.affiliation: Department of Surgery, Division of Otolaryngology Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Czerwonka
authors.forename: Jack J
authors.initials: JJ
authors.lastname: Jiang
authors.forename: Chao
authors.initials: C
authors.lastname: Tao
mesh_terms: D000465:Algorithms; D001696:Biomechanical Phenomena; D001794:Blood Pressure / Q000502:physiology*; D002196:Capillaries / Q000503:physiopathology; D002198:Capillary Fragility / Q000502:physiology*; D005260:Female; D006801:Humans; D007818:Laryngeal Diseases / Q000209:etiology*; D007819:Laryngeal Edema / Q000209:etiology*; D007820:Laryngeal Mucosa / Q000098:blood supply; D008297:Male; D008955:Models, Cardiovascular; D010699:Phonation / Q000502:physiology; D011312:Pressure; D012189:Retrospective Studies; D013314:Stress, Mechanical; D014732:Vibration / Q000009:adverse effects; D014827:Vocal Cords / Q000098:blood supply*; D014831:Voice / Q000502:physiology*