Lidocaine 10% in the endotracheal tube cuff: blood concentrations, haemodynamic and clinical effects.

The purpose of this study was to evaluate the effects (common haemodynamic variables, peak cuff pressures, the incidence of reaction ('bucking') during extubation and the incidence of sore throat after operation) of lidocaine 10% instilled into the endotracheal tube cuff in intubated patients. Plasma concentrations of lidocaine were assayed. Seventy ASA class I-II patients scheduled for plastic surgery were studied. Patients were randomly divided in two groups: the cuff of the endotracheal tube was inflated with either lidocaine 10% (group L) or with saline (group S) immediately after endotracheal intubation. In group L patients, the haemodynamic changes were less (P < 0.05), and the peak cuff pressure was lower (P < 0.01) than for group S. At extubation, more patients reacted ('bucked') in group S (70.5% vs. 19.4%, P < 0.01). The incidence and severity of sore throat were significantly lower in group L 1 and 24-h after extubation. Plasma lidocaine concentrations did not reach toxic values. Lidocaine 10%, compared with saline, in the endotracheal tube cuff was associated with less disturbance of haemodynamic responses and less incidence of bucking during tracheal extubation. Lidocaine was also effective in reducing of incidence and severity of sore throat after operation.