Abstract
We investigated the blood lidocaine concentration during bronchofiberscopy and the effects of the addition of epinephrine. Twelve cases of respiratory disease were divided into two groups receiving lidocaine, either with or without epinephrine. The epinephrine group (EG, n=6) first of all received nebulized epinephrine (1 : 80, 000). Then 2% lidocaine with epinephrine (1 : 80, 000) was sprayed into the larynx. After that the same anesthetic was instilled into the tracheobronchial tree through the work channel of the bronchoscope. In the control group (CG, n=6), these procedures were performed using lidocaine alone. Lidocaine concentrations in the blood were measured 20, 40, 60, and 120 minutes after the administration of lidocaine. The mean total dose of lidocaine used and the mean remaining dose per kilogram of body weight were similar in the two groups. The lidocaine concentration in blood reached a peak at 40-60 minutes in all patients. No significant difference was found in the mean peak concentration of lidocaine between the two groups (EG : 1.9±0.6μg/m, CG : 2.0±0.5μg/ml). The pulse rate during bronchofiberscopy in EG had a tendency to be higher than that in CG. We conclude that the addition of epinephrine did not have a significant effect on the absorption of lidocaine during bronchofiberscopy.
