Briefly describe the extrusion method of closed thoracic drainage tube and how to check whether the drainage tube is unobstructed.

1. Thoracic closed drainage tube is generally hard and can only be squeezed normally. If you can pinch it, you can pinch it near the chest, squeeze the exhaust or liquid to the distal end, then pinch the distal end and loosen the proximal end.

2. Whether the drainage tube is unobstructed, it is recommended that the patient cough hard. If liquid or gas emerges, it will be unobstructed. Or when the patient breathes, the tail liquid column fluctuates with breathing.