Root Cause of Analysis of Peculiar Response of Pneumothorax to Chest Tube Drainage

Abstract

Chest tube drainage is a simple system to manage pneumothorax. It is inserted at the safety triangle after local anesthesia. Due to the positive intrapulmonary pressure and the negative intrapleural pressure during inspiration, air in the pleural space will be forced out into the chest drain bottle with underwater seal. The resorption of pneumothorax is further enhanced by oxygen therapy, which displaces the nitrogen inside the pneumothorax. Out of our expectation, there are cases with peculiar response to chest tube drainage. We should consider the following in the root cause analysis. 1. Chest drain system integrity: The chest drain should be placed in the pleural cavity, rather than sub-cutaneous or intra-abdominal cavity. The tubing should not be kinked or disconnected and the connection site should not be masked by dressing. 2. Anatomy of the pneumothorax: The anatomy of the pneumothorax should be on CXR or preferably contrast CT thorax. Any loculation, endobronchial obstruction, trapped lung due to old inflammatory process, lung entrapment due to persistent active inflammatory process should be noted. 3. Clinical assessment: It includes pleural fluid analysis, if present, and pleural manometry with air aspiration. In case of persistent air-leak seen in the chest drain bottle, suspect alveolopleural or bronchopleural fistula especially when patient is on positive pressure ventilation. Alternating or persistent bilateral pneumothorax without air-leak suggests interpleural communication (Simultaneous Bilateral Spontaneous Pneumothorax). The observed phenomena can be explained by considering the pressure change between various intra-thoracic compartments accounts for the observed phenomena, although confirmation of the communication during thoracoscopy is preferred.