A prospective observational study on assessment of vocal cord injuries after placement of double lumen tube.

Endotracheal tube is required for patients undergoing general anesthesia .Though it is a safe procedure it is not without its risks .It can cause injuries to oral cavity and vocal cords. For procedures requiring lung isolation ,placement of double lumen tube is essential . Double lumen tube has larger diameter and requires more intraoperative manipulations. Thus chances of vocal cord injuries caused by double lumen tubes is also more .Hence plan of this study is to assess vocal cord injuries using stroboscopy. Stroboscopy is based on Talbot law, which states that images persist on the human retina for very short time after exposure. Interpreting sequential images that correspond to an object in motion is a fundamental principle. Consequently stroboscopy leverages these principles by generating intermittent light flashes in close synchronization with the frequency of vocal cord vibration. Thus study of stroboscopy helps to study in depth intricate patterns of vocol cord vibration and mucosal waves. Thus we can identify the injuries at the earliest. Patients would be recruited from thoracic out patient department and stroboscopy  would be performed by Head and neck team. Stroboscopy would be performed twice pre operatively and within 48 hours after placement of double lumen tube.