title: Ear injury caused by elevated intratympanic pressure during general anaesthesia.
abstract: Two cases of middle-ear injury, due to sharp fluctuations of intratympanic pressure as a result of general anaesthesia with nitrous oxide are presented. A study is reported indicating that the degree of these fluctuations is a function of the concentration of nitrous oxide. In order to reduce the risk of middle-ear injury due to nitrous oxide anaesthesia, it is suggested that the lowest concentration feasible should be used where there is a history of previous ear surgery.
mesh_terms: D000328:Adult; D000768:Anesthesia, General / Q000009:adverse effects*; D000769:Anesthesia, Inhalation / Q000009:adverse effects; D001469:Barotrauma / Q000209:etiology* / Q000517:prevention & control; D004305:Dose-Response Relationship, Drug; D004432:Ear, Middle / Q000293:injuries*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide / Q000008:administration & dosage; D011312:Pressure
chemical_list: D009609:Nitrous Oxide