title: Can eustachian tube ventilatory function impairment after oxygen diving be influenced by application of free radical scavenger vitamins C and E?
abstract: OBJECTIVE
  To evaluate the influence of free radical scavenger vitamins C and E on eustachian tube ventilatory function changes related to oxygen dives.
  
  
  METHODS
  Prospective, randomized, double-blind, placebo-controlled study of middle ear impedance changes of oxygen divers being orally treated with free radical scavenger vitamins C and E.
  
  
  METHODS
  Fifteen divers were allocated to two groups. Before diving on oxygen on consecutive days (days 1 and 2), divers in group 1 took a daily dose of 1 g ascorbic acid and 600 International Units d-alpha-tocopherol and divers in group 2 were given placebo. Before diving and 2 and 24 hours after diving on days 1 and 2, middle ear impedance was measured.
  
  
  RESULTS
  Impedance decreased overnight after dive 1 (P =.04) but not after dive 2 (P =.31). No impedance differences were found between groups after the dive on day 1 (P =.83). Twenty-four hours after the dive on day 1 and after the dive on day 2, impedance values in both groups were different (P =.02 vs. P =.07), emphasizing slightly more negative pressures in the vitamin group.
  
  
  CONCLUSIONS
  Vitamins C and E did not reduce eustachian tube ventilatory function impairment overnight after the dive on day 1, suggesting no evidence of free radical-mediated toxicity affecting the eustachian tube or middle ear mucosa. Repetitive oxygen dives may cause tissue adaptation suggesting other than antioxidant defense mechanisms.
authors.affiliation: Department of Anesthesiology and Critical Care, Federal Armed Forces Medical Center, 89070 Ulm, Germany.
authors.forename: T S
authors.initials: TS
authors.lastname: Mutzbauer
authors.forename: B
authors.initials: B
authors.lastname: Neubauer
authors.forename: P H
authors.initials: PH
authors.lastname: Mueller
authors.forename: O
authors.initials: O
authors.lastname: Sigg
authors.forename: K
authors.initials: K
authors.lastname: Tetzlaff
mesh_terms: D000284:Administration, Oral; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D004242:Diving / Q000009:adverse effects*; D004311:Double-Blind Method; D005064:Eustachian Tube / Q000187:drug effects / Q000502:physiology*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans; D010100:Oxygen; D011446:Prospective Studies; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D016166:Free Radical Scavengers; D014810:Vitamin E; D001205:Ascorbic Acid; D010100:Oxygen