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

Cough is the most unwanted response during bronchoscopic interventions. Cough could lead to airway spasm, hemodynamic instability, desaturation, hypoventilation, and then interrupt the following interventions. In previous reports, lodicaine and other drugs given intravenously, inhalationally or trans-cricoidally have been investigated for preventing cough during conventional broncoscopic examinations. As bronchoscopic interventions were goaled to precise localization and operations with higher yield rate. Steady airways without endotracheal tubes are usually required. 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. There are few studies focused on the effects of different drugs for preventing cough even bronchoscopic spary of local anesthetics has become the routine pratice before interventions. In this study, different intravenous drugs (lidocaine, alfentanil, compared to normal saline) are planned to be injected one minutes before bronchoscopic insertion, the responses to bronchoscopic spraying local anesthetic were recorded and analyzed. Besdies cough scores, the following changes are recorded and compared: (1) status on visualization and the responses to spraying of vocal cords, (2) anesthetic depth (BIS levels), ANI scores (3) blood pressure and heart beats, (4) data of hemoglobin saturation (SPO2) and Transdermal O2 and CO2. We goaled to compare the effects of intravenous lidocaine and etomidate on cough intensity, hemodynamics, ventilation, and bronchoscopic withdrawl rate during bronchoscopic interventions with intravenous anethesia.