Intrapulmonary route for drug administration: effects on plasma concentrations and blood gases

ABSTRACT

This work aimed to compare four different methods of endotracheal and bronchial lidocaine administration with respect to the site of administration. Forty-eight patients undergoing elective operations with an anesthetic risk ASA I and II were included in this study. In this study, all other patients received lidocaine under bronchoscopic control through the side channel of bronchoscope either deep endotracheal, into the right main bronchus and into the right lower lobe bronchus. At 10 points of time after drug administration, blood samples were taken for measurements of lidocaine plasma concentration [using high pressure liquid chromatography] and blood gas analysis. Therapeutic blood concentrations [>/ 1.4 mug/ml] could be achieved and toxic blood concentrations [>/ 6 mug/ml] could be avoided with all methods of administration. No significant difference was found between the different methods with regard to peak concentration, time to peak, onset and duration of therapeutic levels or relative bioavailability. A significant decrease in PaO2 to 75% of the baseline was seen with all methods used