Medical Thoracoscopy

Pleural effusion is a common problem in hospital patients. It may arise from a wide range of diseases. There is a multitude of recognised causes of pleural effusion, and in addition, other pleural conditions such as pleural thickening and pneumothorax represent a significant burden to the healthcare system and to patients. However, the diagnosis of this condition may sometimes be difficult. In pleural effusions undiagnosed by thoracocentesis, closed pleural biopsy provides limited yield, whereas the diagnostic yield of thoracoscopy is substantially higher for both malignant and tuberculous pleural effusions. Hence, medical thoracoscopy (MT) (pleuroscopy) is the gold standard in the diagnosis of pleural effusion and it is indicated when less invasive tests have failed. MT is a procedure in which the pleura is directly and visually examined. An endoscope is inserted into the intercostal space by creating a pneumothorax with an incision through the chest wall. The pleural space and its lining can be inspected and therapeutic interventions performed. There are two different techniques that can be performed for diagnostic and therapeutic thoracoscopy. One method recommends a single-entry site, the use of a rigid thoracoscope (or of a semi-rigid/semi-flexible pleuroscope) with a working channel for accessory instruments and an optical biopsy forceps, both performed under local anaesthesia. The other method requires two entry sites: one for a trocar for the examination telescope, and the second for accessory instruments including the biopsy forceps, and is usually performed with conscious sedation or general anaesthesia. In the trained hands of a pulmonologist, MT is a safe and effective procedure for diagnosing and treating multiple pleural diseases. The unfamiliarity of the pulmonary physician with rigid instruments and familiarity with the flexible bronchoscope has led various investigators to attempt thoracoscopy with flexible endoscopes. Flexible instruments allow concurrent suctioning to maintain a clear optical field, providing good views at the apex and paravertebral gutters. This method is considered useful for physicians with experience in chest drainage and flexible bronchoscopy, as well as safe and well tolerated with a minimal degree of discomfort and expense.

Medical thoracoscopy can be performed under procedural sedation (conscious sedation) in most of the cases. Procedural sedation is a state where the patient lies comfortably without much movement, does not feel pain and has a dissociative state (separation of mind and body. In view of the existing literature, we hypothesize that use of dexmedetomidine for procedural sedation during medical thoracoscopy will improve the ease of performing the procedure, lower the consumption of rescue analgesics and risk of intra- and post-procedure complications, improve the yield, shorten the recovery period and reduce the post-procedure pain in comparison to midazolam. In this study we propose to show that procedural sedation with dexmedetomidine during medical thoracoscopy is more beneficial for both patient and the clinician in terms of yield and shorter procedure time in comparison with conventional midazolam-fentanyl combination.