[Intratympanic pressure changes during general anaesthesia (author's transl)].

A common observation during otologic surgery under general anaesthesia, notably with nitrous oxide, is tympanic membrane graft displacement due to elevated intratympanic pressure. It can be assumed that nitrous oxide increases the intratympanic pressure. The authors measured the intratympanic pressure changes with the Madsen Impedance measuring instrument Z073. The results of the measurements of 84 ears are discussed and the tendencies of the connection between pressure in the middle ear and the size of the mastoid bone are shown.