Pleural Tap (Thoracocentesis)

Diagnostic / Therapeutic

Indications

  1. • New unilateral pleural effusion (diagnostic)
  2. • Symptomatic effusion (therapeutic)
  3. • Suspected empyema / haemothorax

Contraindications

  1. ⚠ Uncorrected coagulopathy
  2. ⚠ Skin infection over site
  3. ⚠ Small effusion not localisable on USS

Equipment

  1. • USS machine
  2. • Sterile pack, chlorhexidine, drapes
  3. • 1% lidocaine
  4. • 21G needle + 50 mL syringe for diagnostic; 8 Fr pigtail or large-bore cannula + 3-way tap + drainage set for therapeutic
  5. • Sample tubes incl blood culture bottles

Technique

  1. • Ultrasound-mark site (BTS standard) — usually mid-scapular or posterior axillary line, above rib
  2. • Sit patient leaning forward over pillow
  3. • Sterilise, drape, infiltrate skin → rib → parietal pleura with lidocaine
  4. • Aspirate slowly as you advance — fluid confirms position
  5. • Diagnostic: 30–50 mL into syringes + culture bottles
  6. • Therapeutic: insert pigtail with Seldinger, drain ≤1.5 L per session, stop if cough/chest pain

Complications

  1. ⚠ Pneumothorax
  2. ⚠ Haemothorax (intercostal vessels)
  3. ⚠ Re-expansion pulmonary oedema
  4. ⚠ Visceral puncture (liver, spleen)
  5. ⚠ Infection

Aftercare

  1. • Erect CXR after procedure
  2. • Send: protein + LDH (Light's), pH (heparinised), glucose, cytology, MC&S, AFB

Clinical pearls

  1. • Light's criteria: exudate if any of fluid/serum protein >0.5, LDH >0.6, LDH >2/3 ULN
  2. • pH <7.2 in para-pneumonic → drain
  3. • Always above rib to avoid neurovascular bundle

Perform under supervision until competent. Follow local SOPs and consent policy.

WardRound

WardRound

Clinical Decisions in Seconds