Safety of topical tetracaine in patients undergoing flexible bronchoscopy

Lidocaine is currently the most commonly used topical anesthetic during flexible bronchoscopy (FFB) in North America. Tetracaine, a longer-acting agent, might produce better airway analgesia; however, previous literature has suggested that tetracaine is more risky and can even result in cardiac arrest. The maximum recommended tetracaine dose for topical anesthesia is 20 mg. Over the past 30 years, our Pulmonary Special Procedures Unit has used topical tetracaine in considerably higher doses. In this study, we sought to review the safety of this approach. We completed a retrospective review of all FFBs performed on nonintubated patients by a single bronchoscopist from January 2005 to February 2007. The primary outcome variables included adverse reactions and tetracaine dose administered. Five hundred thirty-seven FFBs were performed on 431 patients. Patient age ranged from 20 to 94 years, with a mean age of 55 years. Eighty-one percent (n=434) of these FFBs were performed using only topical anesthesia. Tetracaine solution 0.45% was used in 99.6% of these procedures. Mean tetracaine dose was 120 mg (range: 18 to 158 mg). No adverse reactions attributable to tetracaine were noted. Specifically, no cardiac or neurologic events occurred. Bronchospasm was noted in 1.5% of patients and 1 patient required intubation after the procedure owing to severe hypoxemia. This retrospective study suggests that topical tetracaine at doses up to 8 times the "recommended" dose is safe for the use during FFB.