Joined: 05 Feb 2006
Location: Devon, UK
|Posted: Mon Feb 06, 2006 9:01 pm Post subject: Drains
|Regardless of the cause, the aim of treatment of pneumothorax is to eliminate the collection of air from the pleural cavity. Invasive techniques are required if the pneumothorax occupies greater than 15% of the involved hemithorax, is progressive over time, or, if the patient is symptomatic.
Needle aspiration may be carried out as the first treatment of Primary spontaneuos pneumthoraces without tension. local anesthetic is applied as deep as to the pleura before directing a needle over the top of the rib into the desired intercostal space. A small catheter can then be placed in the chest via the fourth or fifth intercostal space at the anterior axillary line, and the air removed via suction techniques with a 60 mL syringe and a 3-way stopcock. Patients must then be observed as subsequent intercostal drainage may be necessary. needle aspiration is shown to be useful in some cases. However the failure rate is high and aspiration cannot therefore be thought of as a single complete treatment for this condition.
Intercostal chest tube
If simple aspiration or catheter aspiration drainage of any pneumothorax is unsuccessful in controlling symptoms, then an intercostal tube may be inserted.
A chest tube or chest drain is a flexible plastic tube that is inserted through the side of the chest into the pleural space. It is used to remove air (pneumothorax) or fluid (pleural effusion, blood, chyle), or pus (empyema) from the intrathoracic space.
The free end of the tube is usually attached to an underwater seal, below the level of the chest. This allows air or fluid to escape from the pleural space, and prevents anything returning to the chest. Alternatively, the tube can be attached to a flutter valve. This allows patients with pneumothorax to remain more mobile.
Chest tubes are usually inserted under local anesthesia. The skin over the area of insertion is first cleansed with antiseptic solution before sterile drapes are placed around the area. The local anesthetic is injected into the skin and down to the muscle, and after the area is numb a small incision is made in the skin and a passage made through the skin and muscle into the chest. The tube is placed through this passage. If necessary, patients may be given additional painkillers for the procedure. Once the tube is in place it is stitched to the skin to prevent it falling out and a dressing applied to the area. The tube stays in for as long as there is air or fluid to be removed.
Underwater seal drainage using a chest tube was introduced in 1875. Widespread closed tube drainage was first adopted during the 1917 influenza epidemic. Intercostal tube drainage or underwater seal drainage in its modern form has been in use since 1916 when Kenyon described a siphon method of draining traumatic haemothorax. This treatment, despite being extremely effective, has many potential disadvantages ranging from chest and abdominal visceral trauma from sharp trocars in the hands of inexperienced operators.
The water-seal (tube immersed in water) acts as a one way valve, so that air can escape from the pleural space, yet not return. More air bubbles will be noted when the patient coughs, sneezes or exhales. If there is no bubbling, there is either a blockage in the chest tubing, or expansion of the patient's lung has occurred and there is no longer air in the pleural space.
Chest drain - suction
If suction is added to the water seal system, the subatmospheric pressure is further reduced, promoting air or fluid to move from the higher to the lower pressure more rapidly.
Suction to an intercostal tube should not be applied directly after tube insertion, but may be added after 48 hours for persistent air leak or failure of a pneumothorax to re-expand.
High volume, low pressure (10 to 20 cm H2O) suction systems are recommended.
Patients requiring suction should only be managed on lung units where there is specialist medical and nursing experience.
There is no evidence to support the routine initial use of suction applied to chest drain systems in the treatment of spontaneous pneumothorax. A persistent air leak, with or without incomplete re-expansion of the pneumothorax on a chest radiograph, is the usual reason for applying suction to an intercostal tube system. A persistent air leak is usually arbitrarily defined as a continued air bubbling through an intercostal tube 48 hours after insertion.
The Heimlich valve is a one-way, rubber flutter valve. The proximal end attaches to the chest tube, and the distal end connects to a suction device or is left open to the atmosphere. It allows outpatient treatment of a pneumothorax.