Growth Inhibition of Mycobacteria by Lidocaine in Fiberoptic Bronchoscopic Aspirates

Abstract

Fiberoptic bronchoscopy was performed on 27 cases. Local anesthesia achieved with a 2% solution of Lidocaine, and bronchial aspirates were collected throughout the procedure. The drug concentration of Lidocaine in these aspirates was between 0.017 and 1.5mg/ml ; the mean was 0.6mg/ml. The in vitro study revealed that Lidocaine inhibited the growth of Mycobacteria in the above-mentioned range, particularly when more than 1mg/ml. The growth inhibition of Mycobacteria was dependent on the drug concentratin of Lidocaine and duration of exposure. It may be concluded that in order to increase the diagnostic yield of pulmonary tuberculosis using fiberoptic aspirates, it is important to decrease the contamination of Lidocaine, and perform the routine culture method as soon as possible.