Pleural aspiration

Drainage of fluid from the pleural space using needle, cannula, or flexible small-bore drain. Increasingly being performed under ultrasound guidance. Blood/pus often requires large-bore drain insertion.

Indications

• Improvement of blood gases.

• Symptomatic improvement of dyspnoea.

• Diagnostic ‘tap’.

Contraindications/cautions

•  Coagulopathy.

Technique

1 Confirm presence of effusion by CXR or ultrasound.

2 Select drainage site either by maximum area of stony dullness under percussion or under ultrasound guidance.

3 Use aseptic technique. Clean area with antiseptic and infiltrate local skin and subcutaneous tissues with 1% lidocaine. Advance into deeper tissues, aspirating to confirm absence of blood, then infiltrate with local anaesthetic until pleura is pierced and fluid can be aspirated.

4 Advance drainage needle/cannula/drain slowly through chest wall and intercostal space (above upper border of rib to avoid neurovascular bundle). Apply gentle suction until fluid is aspirated.

5 Withdraw 50mL for microbiological (M, C & S, TB stain, etc.), biochemical (protein, glucose, etc.) and histological/cytological

(pneumocystis, malignant cells, etc.) analysis, as indicated.

6 Either leave drain in situ connected to a drainage bag or connect needle/cannula by a three-way tap to a drainage apparatus.

7 Continue aspiration/drainage until no further fluid can be withdrawn or if patient becomes symptomatic (pain/dyspnoea). Dyspnoea or haemodynamic changes may occur due to removal of large volumes of fluid (>1–2L) and subsequent fluid shifts; if this is considered to be a possibility, remove no more than 1L at a time, either by clamping/ declamping drain or repeating needle aspiration after an equilibration interval (e.g. 4–6h).

8 Remove needle/drain. Cover puncture site with firmly applied gauze dressing.