A chest drain (intercostal drain) removes air, blood or fluid from the pleural space, allowing the lung to re-expand. Drains are used for pneumothorax, pleural effusion, empyema, haemothorax (often after trauma) and after chest surgery. Poorly managed drains can cause serious harm, so the British Thoracic Society recommends that patients with drains are cared for on wards where staff are trained in their management.
How an underwater seal works
The tube from the chest runs into a bottle, with the end submerged under about 2–3 cm of sterile water. Air and fluid can escape from the chest into the bottle, but the water acts as a one-way valve preventing air from being sucked back in. That is why the bottle must always stay below the level of the chest and upright.
The three things to check: swinging, bubbling, draining
| Check | What it means | Concern |
|---|---|---|
| Swinging (fluid in the tube rises and falls with breathing) | The drain is patent and in the pleural space | Stopped swinging: tube blocked, kinked, displaced, or lung fully re-expanded. Check and report |
| Bubbling | Air is leaving the pleural space (expected with a pneumothorax) | Continuous bubbling may indicate an ongoing air leak or a leak in the system; new bubbling in a drain for fluid should be reported |
| Draining | Volume and type of fluid (serous, bloody, purulent) | Sudden large volumes, especially fresh blood (e.g. over 100–200 mL/hr after trauma or surgery), need urgent review |
When draining a large pleural effusion, the BTS advises draining no more than about 1.5 litres at once (or as instructed), because rapid drainage can cause re-expansion pulmonary oedema. Watch for coughing, chest discomfort and breathlessness.
Routine nursing care
- Observations including RR, SpOâ‚‚, pulse, BP, temperature, pain, and the early warning score.
- Check the insertion site: dressing intact, no leaking, signs of infection, surgical emphysema (crackling under the skin).
- Secure the drain to prevent pulling; check sutures and that connections are tight.
- Keep tubing free of kinks and loops where fluid can collect.
- Record drainage by marking the bottle level with time and date, at least each shift (or hourly when draining large volumes).
- Pain relief, so the patient can breathe deeply, cough and move.
- Encourage mobilisation, carrying the bottle below chest level.
- Change the bottle when it is about three-quarters full, according to policy and with aseptic technique.
Clamping: be very careful
Never clamp a bubbling drain. Clamping can cause a tension pneumothorax, a life-threatening emergency. Drains should be clamped only on specific medical instructions (for example, to control drainage of a large effusion), and never during transfer unless instructed. Keep clamps at the bedside for emergencies such as a disconnection or a broken bottle, per local policy.
Emergencies
- Disconnection or broken bottle: reconnect to a new sterile system as quickly as possible, or briefly clamp/kink the tube while you do so, then unclamp. Assess the patient and inform the doctor.
- Drain falls out: cover the site immediately with a sterile occlusive dressing, assess the patient, give oxygen and call for help.
- Tension pneumothorax: sudden worsening breathlessness, low SpOâ‚‚, falling BP, rising heart rate, deviated trachea. Call the emergency team.
Removal
Drains are removed when the doctor confirms (often with a chest X-ray) that the lung has re-expanded, bubbling has stopped, and drainage has reduced. Give analgesia beforehand. The patient is usually asked to hold their breath or perform a Valsalva manoeuvre while the drain is removed, and the wound is closed with a suture or occlusive dressing. Monitor afterwards for breathlessness and re-accumulation.
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Based on British Thoracic Society pleural disease guidance and standard chest drain nursing practice. Educational content: follow your local chest drain policy.