Chest drains are tubes which are inserted into the pleural space, the cavity which surrounds the lungs, for the purpose of draining fluid or air. A doctor may determine that chest drains should be inserted for the purpose of treating a variety of conditions involving the lungs. Once inserted, the drain is left in place until it has fulfilled its purpose, and then it can be carefully removed to allow the patient to heal.
Pleural effusion, in which fluid builds up in the pleural space and makes it difficult for the patient to breathe, is one reason to insert a chest drain. Fluids can include water, blood, or pus from an active infection. As the fluid builds up it puts pressure on the lungs which makes them difficult to inflate, causing the patient to develop labored breathing. Likewise, in pneumothorax, air pockets are present in the pleural space, causing difficulty breathing. Chest drains provide a way for this material to exit the pleural space.
The chest tube must be carefully inserted to avoid injuring the lung. The patient is given anesthetic because the insertion would be painful otherwise, and the doctor works carefully to avoid causing injuries. Once the tube is in place, an x-ray will be used to confirm that it is in the correct location. Chest drains may be sutured or taped in place, depending on the patient's level of mobility.
While a chest drain is in, the tube outside the body is kept below the level of the patient. This is designed to prevent backflow, ensuring that air and fluids move out of the drain, but not back into it. The end of the tube can be connected to a chest drain canister which also acts to prevent backflow by creating a seal, or to a collection bag connected with a one-way flutter valve. As the lungs drain, the output of the chest drain is monitored.
When the drainage is reduced to a level deemed acceptable by a doctor, the chest drain is removed. Changes in the material collected from the chest drains, such as collections of pus, can indicate that there is a medical complication which requires attention. If a chest drain starts to pull out for any reason, the patient should immediately inform a doctor or nurse. Once a chest drain starts to pull out, it should not be forced back in as this can expose the patient to the risk of infection in addition to potentially causing injuries to the lung.