Abstract
When 4% Lidocaine solution was used for topical anesthesia, bacteriologic examination of tracheo-bronchial secretions occasionally showed negative cultures for bacteria in spite of the demonstration of microorganisms on direct smear tests.
To see if the anesthetic solution had any effect in producing these contradictory results, experiments were carried out with pure bacterial cultures and it was found that 4% Lidocaine solution suppressed the growth of bacteria.
Therefore, in order to assure accurate results whenever secretions are taken for bacteriologic examination, one should be careful not to take specimens that might contain some of the anesthetic solution.
