312.3 🏥 內科專科考前版

312.3.1 Mechanistic Deep Dive

312.3.1.1 Pleural Fluid Production + Drainage

  • Parietal pleural arterial supply
  • Drainage via lymphatics through parietal stomata
  • Imbalance → effusion
  • Lymphatic blockade → chylothorax

312.3.1.2 Empyema Formation

  • Bacterial invasion of pleural space
  • Neutrophil infiltration
  • Pus formation
  • Loculations from fibrin
  • Untreated → fibrothorax → trapped lung

312.3.2 Recent Trials & Updates

312.3.2.1 MIST-2 (2011) — Intrapleural Therapy

  • N = 210 empyema
  • tPA + DNase combination vs each alone
  • ↓ Surgical referral
  • Pleural drainage volume increased
  • Practice-changing

312.3.2.2 IPC-PLUS (2017)

  • Tunneled pleural catheter (TPC) + talc pleurodesis
  • Effective for malignant effusion
  • Outpatient option

312.3.2.3 MesoCheck (2023) — Mesothelioma Screening

  • Biomarker-based screening high-risk individuals
  • Future role

312.3.2.4 EMPIRE (2024)

  • Empyema management trial
  • IL-1β role
  • Future biologic targeting

312.3.2.5 TIME2 + AMPLE (2021)

  • Indwelling pleural catheter vs talc pleurodesis for malignant effusion
  • Equivalent efficacy
  • TPC for outpatient convenience

312.3.3 High-Yield Specialist Points

312.3.3.1 Empyema Antibiotics

  • Community: ampicillin-sulbactam, piperacillin-tazobactam, ceftriaxone + metronidazole
  • Anaerobic coverage important (Bacteroides, Peptostreptococcus)
  • Healthcare-associated: broader (vanc/linezolid for MRSA, anti-pseudomonal)
  • Duration: 4-6 weeks
  • Switch to oral when stable + drainage

312.3.3.2 TB Pleurisy Diagnosis

  • ADA > 40 IU/L (high sensitivity)
  • Lymphocytic exudate
  • IFN-γ in pleural fluid
  • Pleural biopsy (granulomas in 60-80%)
  • Treatment: standard 6-month TB regimen
  • May resolve spontaneously but recurrence in 65% within 5 years

312.3.3.3 Trapped Lung

  • Chronic visceral pleural thickening → lung cannot expand
  • Persistent effusion (post-thoracentesis “ex vacuo” pleural pressure)
  • Treatment: pleurectomy + decortication

312.3.3.4 Lung Entrapment

  • Acute version of trapped lung
  • Active inflammation
  • May resolve with treatment

312.3.3.5 Chyle-Like Effusion

  • TG 50-110 mg/dL
  • Could be either chyle or pseudo (cholesterol crystals)
  • Lipid analysis distinguishes

312.3.3.6 Hemothorax Management

  • Large-bore (32-36F) chest tube

  • 1.5 L initial or > 200 mL/h × 3-4 hours → surgery

  • VATS for retained hemothorax (within 3-7 days)
  • Tranexamic acid in trauma (CRASH-2 inferred)

312.3.3.7 Iatrogenic Pneumothorax

  • Risk varies by procedure (1-30%)
  • Most resolve spontaneously
  • Watch for tension
  • Chest tube if symptomatic or large

312.3.3.8 Pleural Drainage Catheter Choices

  • Small bore (8-14F): for simple effusion
  • Medium (16-24F): for complicated
  • Large bore (28-40F): for empyema, hemothorax

312.3.3.9 Tunneled Pleural Catheter (TPC, PleurX)

  • For recurrent malignant pleural effusion
  • Outpatient drainage 3x/week
  • Spontaneous pleurodesis in 50%+
  • Less hospitalization than recurrent thoracentesis

312.3.3.10 Mesothelioma Subtypes + Treatment Response

  • Epithelioid: more chemo-responsive
  • Sarcomatoid: less; immunotherapy may help
  • Biphasic: intermediate
  • 2024: PD-L1 + neoadjuvant immunotherapy emerging

312.3.3.12 Catamenial Pneumothorax

  • Recurrent during menstruation
  • Thoracic endometriosis (often diaphragmatic)
  • Right-sided usually
  • Treatment: hormonal suppression + VATS
  • Considered in young female with recurrent pneumothorax

312.3.3.13 Air Travel + Pneumothorax

  • Generally avoid for 1-2 weeks post-resolution
  • Risk of expansion at altitude
  • Earlier OK if very small + stable

312.3.4 Pearls

  • Light’s criteria for exudate vs transudate
  • Transudate: HF, cirrhosis, nephrotic, atelectasis
  • Exudate: parapneumonic, malignancy, PE, TB, autoimmune
  • Complicated parapneumonic (pH < 7.30, LDH > 1000, glucose < 60): chest tube + abx
  • MIST-2: tPA + DNase for loculated empyema
  • PSP: tall thin young men; small → observe + O2
  • SSP: underlying lung disease; chest tube + pleurodesis
  • Tension pneumothorax: immediate needle decompression
  • Mesothelioma: nivolumab + ipilimumab (CheckMate 743)
  • TPC (PleurX): outpatient for malignant effusion