[Short-term changes in the larynx and voice after intubation].

The endoscopic and stroboscopic picture of the larynx as well as the voice were examined pre-operatively and on the first or second post-operative day in 75 patients who had been anaesthesized with intubation. The stroboscopic findings were evaluated according to the criteria suggested by Schürenberg (1990). The quality of the voice was estimated with a voice purity index (Moser 1984) and the dynamic and frequency range of the voice was measured. After intubation, we found alterations of the mucous membrane in 73% of the patients: increased amount of visible blood vessels, bleeding into the vocal cords or the trachea, bruises at the processus vocals or the arytenoid cartilages. The stroboscopic picture showed deterioration: pre-operatively large amplitudes and/or mucosal waves became even larger postoperatively, small amplitudes and mucosal waves decreased even further. The timing and the spatial symmetry of the vocal cord movements also deteriorated. On the average, the dynamic range and the frequency range of the voice did not change. However, in individual cases the changes were considerable. The same was true for the parameters of the voice purity index. There was no statistically significant dependency on sex or age of the patients, the duration of the intubation or the diameter of the intubation tube.