Makindo Medical Notes

💡 Key Point: The “meniscus” on CXR is a visual illusion caused by thoracic shape – not a true meniscus. 💉 Diagnostic tap: 20 mL syringe + 21G needle → send fluid for protein/LDH, cell count, culture (inc. TB), and cytology. ⚠️ Large-volume rapid drainage risks re-expansion pulmonary oedema → always drain slowly with monitoring.

📖 About

• 🫁 Pleural effusion = fluid in pleural space → impaired lung expansion + breathlessness.
• 🔍 Suggests underlying lung/pleural/systemic disease (infection, malignancy, systemic illness).

🔄 Types

• 💧 Pleural Effusion: Fluid in pleural space.
• 🌬️ Pneumothorax: Air in pleural space.
• 🟢 Empyema: Pus in pleural space (often post-infection).
• 🩸 Haemothorax: Blood, usually trauma/malignancy.
• 🥛 Chylothorax: Milky lymph (thoracic duct injury/malignancy).

🧪 Aetiology

• Causes: inflammation, malignancy, ↑ permeability, or osmotic imbalance.
• 🔎 Classified by Light’s Criteria → Exudates (high protein) vs Transudates (low protein).

🩺 Clinical (detectable if >500 mL)

• 😮 Progressive breathlessness.
• ⚡ Pleuritic chest pain (esp. inflammatory).
• 📉 Reduced chest movement on affected side.
• 🔨 Stony dull percussion.
• ➡️ Mediastinal shift/tracheal deviation in large effusions.
• 🔇 ↓ breath sounds + vocal resonance over fluid.
• 🎶 Bronchial breathing above fluid level.

📊 Light’s Criteria – Exudate if ≥1 present

• Protein ratio (pleural/serum) > 0.5
• LDH ratio (pleural/serum) > 0.6
• Pleural LDH > ⅔ upper serum LDH normal

🔍 Classical Findings by Cause

• 🎗️ Cancer: Serous/bloody exudate. Cytology/biopsy may show malignant cells.
• ❤️ Heart Failure: Transudate, straw-coloured. Responds to diuretics. BNP↑.
• 🦠 Tuberculosis: Amber fluid, lymphocytosis, exudative. ADA↑.
• 🫀 Pulmonary Embolism: Clear/blood-stained. Exudate or transudate.
• 🦴 Rheumatoid: Turbid, high lymphocytes, low glucose, cholesterol crystals.
• 🌸 SLE: Serous, lymphocytic. ANA/anti-DNA positive.
• 🔥 Pancreatitis: Bloody/serous, amylase↑.
• 🥛 Chylothorax: Milky (chylomicrons present).

📌 Causes Using Light’s Criteria

• Exudates: (high protein/LDH)
  • Bacterial pneumonia, TB, abscess, fungal.
  • Malignancy: carcinoma, lymphoma, mesothelioma.
  • Autoimmune: RA, SLE, vasculitis.
  • Pancreatitis, oesophageal rupture.
  • Radiation/asbestos lung injury.
• Transudates: (low protein/LDH)
  • Heart failure, nephrotic syndrome, cirrhosis.
  • Hypoalbuminaemia, peritoneal dialysis.
  • Urinothorax (urinary obstruction).
  • CSF leak into pleural space.

💉 Therapeutic Tap

• Indicated if breathless/unclear cause. Avoid in HF unless diuretic-resistant.
• Relieves symptoms + diagnostic yield.
• 🔎 Use small-bore (10–14F) drain, ideally US-guided.
• ⚠️ Drain slowly & intermittently → prevent re-expansion pulmonary oedema.
• 🟢 Empyema → antibiotics + larger drain ± intrapleural fibrinolytics.

📚 References

• BTS Pleural Guidelines
• BMJ Best Practice: Pleural Effusion

4 Clinical Cases — Pleural Effusion 🌊🫁

• Case 1 — Heart failure (transudate) ❤️: A 72-year-old man with worsening orthopnoea and ankle swelling. CXR: bilateral, symmetric pleural effusions with blunting of costophrenic angles. BNP elevated. Teaching: Transudative effusions from raised hydrostatic pressure (HF, nephrotic syndrome, cirrhosis). Treat underlying cause + diuretics; thoracocentesis if symptomatic.
• Case 2 — Pneumonia (parapneumonic effusion) 🦠: A 46-year-old woman with fever, pleuritic chest pain, and productive cough. CXR: left lower lobe consolidation with associated effusion. Pleural fluid: exudate, neutrophil-predominant, pH 7.1. Teaching: Exudates arise from inflammation/infection. Low pH and low glucose suggest complicated effusion/empyema → chest drain often required.
• Case 3 — Malignancy (exudate) 🎗️: A 65-year-old woman with weight loss and dyspnoea. Ex-smoker, history of breast cancer. CXR: right-sided large effusion, mediastinal shift to opposite side. Pleural tap: exudate with malignant cells. Teaching: Malignant effusions often recur. Options: repeated aspiration, indwelling pleural catheter, or talc pleurodesis for palliation.
• Case 4 — Tuberculous effusion 🧫: A 29-year-old man recently arrived from South Asia with fever, night sweats, and pleuritic chest pain. CXR: unilateral pleural effusion, no obvious consolidation. Pleural aspirate: straw-coloured exudate, lymphocyte-rich, ADA elevated. Teaching: TB effusions are usually unilateral, lymphocytic exudates. Diagnosis via pleural biopsy or PCR. Requires full anti-TB therapy.