312.2 🩺 國考版

312.2.1 高頻考點

312.2.1.1 Light’s Criteria (MEMORIZE)

Exudate if ≥ 1: - Pleural protein / serum protein > 0.5 - Pleural LDH / serum LDH > 0.6 - Pleural LDH > 2/3 upper limit serum LDH

312.2.1.2 Specific Diagnoses by Pleural Fluid

  • pH < 7.20: complicated parapneumonic, RA, malignancy, TB
  • Glucose < 60: same + lupus
  • ADA > 40: TB pleurisy
  • TG > 110: chylothorax
  • Cholesterol > 200: pseudochylothorax
  • Amylase very high: esophageal rupture
  • Pleural/serum Hct > 50%: hemothorax

312.2.1.3 Parapneumonic Effusion Management

  • Simple: pH > 7.30, LDH < 1000, glucose > 60 → antibiotics
  • Complicated: pH < 7.30 OR LDH > 1000 OR glucose < 60 → chest tube
  • Empyema: frank pus or + Gram → chest tube + antibiotics
  • Loculated: tPA + DNase (MIST-2)

312.2.1.4 Spontaneous Pneumothorax

  • PSP: tall thin young men (15-35), smokers, family history
  • SSP: underlying lung disease (COPD most common, CF, ILD, PCP, cancer)
  • Catamenial: recurrent during menstruation; thoracic endometriosis

312.2.1.5 Tension Pneumothorax

  • Hemodynamic compromise
  • EMERGENCY: needle decompression (2nd ICS MCL or 4-5th ICS MAL) → chest tube

312.2.1.6 Recurrence Prevention

  • VATS pleurodesis + bullectomy
  • After first SSP or recurrent PSP

312.2.1.7 Malignant Pleural Effusion

  • Cytology (50-70% sensitivity)
  • Pleural biopsy (90%+ via VATS)
  • Management: therapeutic thoracentesis → pleurodesis or PleurX

312.2.1.8 Mesothelioma

  • Asbestos latency 20-40 years
  • Subtypes: epithelioid (60% best), sarcomatoid (worst), biphasic
  • CheckMate 743: nivolumab + ipilimumab first-line

312.2.1.9 Trials

  • MIST-1 (2005): streptokinase only — neg
  • MIST-2 (2011): tPA + DNase combination — positive
  • CheckMate 743: nivolumab + ipi mesothelioma

312.2.2 易混淆比范

Fluid Type Glucose pH LDH Cause
Transudate Normal Normal Low HF, cirrhosis
Simple parapneumonic Normal > 7.30 < 1000 Pneumonia
Complicated < 60 < 7.30 > 1000 Pneumonia + need drain
Empyema < 60 < 7.20 > 1000 Frank pus
Malignancy Variable Variable High Cancer
TB Variable Variable High TB (ADA > 40)
RA Very low < 7.20 High RA pleuritis

312.2.3 Special Topics

312.2.3.1 Tension Pneumothorax Clinical

  • Hypotension, tachycardia
  • Tracheal deviation away
  • Distended neck veins
  • Distant breath sounds
  • Cyanosis
  • DON’T wait for CXR — treat clinically

312.2.3.2 Bilateral vs Unilateral Effusions

  • Bilateral: typically transudate (HF, cirrhosis, hypoalbuminemia, nephrotic)
  • Unilateral: typically exudate (parapneumonic, malignancy, PE, TB)

312.2.3.3 Recurrent Pleural Effusion Workup

  • Multiple cytology
  • Bronchoscopy if hemoptysis or suspicious
  • VATS for definitive
  • PleurX or pleurodesis