Chest drains or thoracic drains/chest tubes/thoracostomy drains/tubes are drains that are used to remove any air (pneumothorax) or fluid (pleural effusion) that builds up in the pleural space due to variable reasons.^1,3 Thoracostomy tubes are indicated in cases of recurrent pneumothorax, tension pneumothorax, pyothorax, rapidly forming pleural effusion, and postoperative management of thoracotomy patients.¹

The placement of these tubes can be a life-saving intervention especially if this evacuation cannot be performed by thoracocentesis or if the production rate is too high.³ If a thoracocentesis has to be performed more than 3 times in 12–24 hours, then a chest drain should be placed.³ They allow either frequent intermittent evacuation of the pleural space or continuous evacuation if connected to a continuous suction device. As well as draining pleural effusion or pneumothorax, these tubes can be used to perform pleurodesis or administration of local or regional analgesia. Pleurodesis consists of the delivery of a substance (whole blood or chemotherapeutic drug) via the chest drain into the pleural space with the intent of obliterating the space, promoting adhesion of the pleural membranes.³ Thoracostomy tube placement is contraindicated in patients with coagulopathies.¹

There are three different types of chest drains: trocar drains, small bore wire guided drains, or red rubber catheters.³ Trocar drains are stiffer, less prone to kinking but cause more discomfort to the patient during placement, and so a general anaesthetic is required. Small bore wire guided drains are placed using the Seldinger technique. These are the most commonly placed drains as their smaller bore causes less discomfort to the patient, but still, a general anaesthetic can be performed. Sterile red rubber catheters are used if no other options are available. Fenestrations can be made into the tube to improve its draining capacity.³

In order to place any of these tubes it is necessary to know the technique very well and to be comfortable with it. As well as knowing the technique, all the material should be prepared beforehand.

List of required material:

• Chosen chest tube (size comparable to the diameter of the mainstem bronchi)
• 14–16 Fr for small dogs/cats
• 24–26 Fr for large dogs
• Christmas tree connector
• Tubing with Luer Lock
• Non collapsing extension set
• 3-way tap
• Scalpel blades
• Haemostats, scissors, needle holders
• Sterile swabs
• Tube clamp
• Bandage material³

Regardless of the chosen tube type and because it is a painful procedure, a general anaesthetic/sedation should be performed. If a large bore trocar tube is chosen, the patient’s airway should be secured with an endotracheal tube. The patient should never be ventilated during the insertion or advancement of the trocar, minimising the risks of lung puncture.³ Pre-oxygenation is advised prior to induction.¹ Once anaesthetised, the patient should be placed in lateral recumbency, have the lateral aspect of the chest clipped between the 6th–10th intercostal spaces, and then have this area aseptically prepared. Intercostal block analgesia can be administered, making the insertion of the chest tube less painful.³

If a red rubber tube or trocar is the chosen tube, after aseptic preparation of the thoracic wall, an assistant pulls the skin cranially. The surgeon placing the tube can choose between two different techniques:

1.  Full-thickness incision

a.  Make a full thickness incision at the 10th–11th intercostal space

b.  Advance tube through to the level of the 7th/8th intercostal space³

2.  Partial thickness intercostal incision

a.  Make a partial thickness intercostal incision

b.  Bluntly dissect with haemostat forceps

c.  Holding the distal end of the tube with the non-dominant hand, start advancing, avoiding over-advancement³

Once in, the tube should be reoriented to advance in a cranioventral direction and the assistant releases the skin, creating a tunnel for the tube. The tube should then be connected to a 3-way tap and using a syringe, the chest should be drained. A chest radiograph should be performed to confirm position. A purse string suture is placed around the base of the tube, and the tube secured with a Chinese finger trap suture.³

If a wire guided tube is chosen, once the thoracic wall is prepared, a skin incision is made between the 7th–9th intercostal spaces and an over-the-needle catheter is inserted into pleural space. The stylet is then removed and the guidewire advanced through the catheter into the pleural space. The catheter is then removed allowing the chest drain to be advanced over the guidewire. As with trocar or red rubber tubes, a radiograph should be performed to confirm position and then the tube should be secured to the thoracic skin.³

These tubes require 24-hour supervision and should be handled in an aseptic manner, using gloves at all times.^1,3 A bandage or some kind of barrier should be used to protect the incision site and tube and should be changed daily. An Elizabethan collar should be worn by the patient at all the times to avoid complications. The drain should always be clamped when not being drained in order to prevent the entry of air into the pleural space.^1,3 The insertion site should be evaluated at least once daily for signs of subcutaneous emphysema, as well as for signs of inflammation or infection such as redness, pain, heat or swelling and/or purulent discharge.¹ When manually draining a pneumothorax/pleural effusion, an empty syringe should be connected to a 3-way tap which is connected to the chest tube.¹ The tube is then gently aspirated until negative pressure is obtained. Once this happens, the patient should be repositioned to understand if the movement will allow any further drainage or not.¹ An analgesia plan should be decided and could include the administration of local anaesthetic into the pleural space making drainage more comfortable.³ Respiratory rate and effort should be monitored and recorded to evaluate trends and assess frequently for any abnormalities.

Chest drains should be removed as soon as they are no longer needed. The decision to pull the tube should be based on the amount of fluid/air that is being drained. In a pneumothorax case, if no or minimum air is produced, the tube can be removed. In a pleural effusion case, the tube can be pulled out when the fluid production volume is low and is not causing respiratory distress to the patient.³

The placement of these tubes carries possible complications such as infection, haemorrhage, visceral injury, re-expansion pulmonary oedema, occlusion/kinking of tubing, and patient interaction with tubing.³

References

1.  Lombardi R, Savino E, Waddell LS. Pleural space drainage. advanced monitoring and procedures for small animal emergency and critical care. In: Aspinall V, ed. The Complete Textbook of Veterinary Nursing, 2nd ed. Elsevier Health Sciences. 2012:378–392.

2.  Dodd L. Critical patient care (venous catheters, urinary catheters, drains). In: The 13th Annual EVECCS Congress Proceedings. 2014.

3.  Lynch A, Campos S. Thoracostomy tube placement. In: Textbook of Small Animal Emergency Medicine. 2018:1199–1201.