Effects of Adding Different Drugs for Preventing Cough Induced by Bronchoscopic Spraying of Local Anesthetics

Cough is the most unwanted response during bronchoscopic interventions for hemodynamic instability, hypoxemia, and interruption of interventions. Topical lidocaine is recommended with a grade evidence in British Thoracic Society guideline. However, severe cough often induces during the initial bronchoscopic spraying of local anesthesia, follows with uneven spraying, spasm or arrythmias. In previous reports, there were many drugs and techniques investigated for preventing cough during broncoscopic spraying. As bronchoscopic interventions need more space and stability of airways to precisely operate on, few studies have focused on the effects of different drugs for preventing cough. In this study, Different intravenous drugs (lidocaine, alfentanil, compared to normal saline) is planned to be injected one minutes before bronchoscopic insertion, the responses to bronchoscopicly spraying local anestheticsuch as cough intensity, BIS levels, ANI, Transdermal O2 and CO2, respiration were recorded and analyzed.