A Comparison of Carbocaine-Thesat® and Lidocaine as Surface Anaesthetics for the Lower Respiratory Tract

In this study, 189 patients were anaesthetized with local anaesthetics for bronchographic x-ray examination. Carbocaine-Thesat (4 + 1)% and lido-caine (4%) were compared in a double blind test. The anaesthetic solutions were used both with and without epinephrine. There was no difference between Carbocaine-Thesat and lidocaine in the onset of anaesthesia. When the group without epinephrine in the anaesthetic solution was compared with the epinephrine group the difference was significant (p<0.01). If epinephrine is added the onset of anaesthesia is slower on the tracheal mucosa. The durations of anaesthesia without epinephrine in the local anaesthetic solutions were compared. The mean for Carbocaine-Thesat was 61 minutes and for lidocaine 102 minutes. The results seem to suggest that it is not advisable to add vasoconstrictors to local anaesthetic solutions for surface anaesthesia of the lower respiratory tract.