303.1 🎓 醫孞生版

303.1.0.1 📌 䞀頁重點

303.1.0.1.1 Imaging
303.1.0.1.1.1 Chest X-Ray (CXR)
  • First-line for most pulmonary symptoms
  • PA + lateral views standard
  • Portable AP in ICU/ED (less detail)

Key Patterns: - Pneumonia: consolidation - Pulmonary edema: bilateral interstitial → alveolar infiltrates, Kerley B lines, peribronchial cuffing, cardiomegaly - PE: often normal; Westermark sign (oligemia), Hampton hump (peripheral wedge), Fleischner sign - Pneumothorax: lung edge, no markings beyond - Effusion: blunted costophrenic angle, meniscus - ILD: reticular, interstitial, honeycomb (severe) - Atelectasis: linear opacity, volume loss - Mass: nodule (< 3 cm) or mass (≥ 3 cm) - Lymphadenopathy: mediastinal widening, hilar enlargement

303.1.0.1.1.2 High-Resolution CT (HRCT)
  • Thin slices (1-2 mm), reconstruction
  • Gold standard for ILD evaluation
  • Bronchiectasis, emphysema, ground-glass, mosaic perfusion, honeycomb
  • Inspiratory + expiratory + prone protocols
303.1.0.1.1.3 CT Pulmonary Angiography (CTPA)
  • Gold standard for PE
  • Contrast-enhanced
  • Filling defect in pulmonary arteries
  • Sensitivity ~ 95% for proximal; less for sub-segmental
303.1.0.1.1.4 V/Q Scan
  • Inhaled radiolabeled (Tc-99m DTPA) + IV (Tc-99m MAA)
  • Mismatched defects (V > Q) = PE
  • Alternative for pregnancy, CKD, contrast allergy
  • Less specific than CTPA
303.1.0.1.1.5 PET-CT
  • FDG uptake
  • Cancer staging (NSCLC standard)
  • Inflammation
  • Sarcoid activity
  • Lymphoma
303.1.0.1.1.6 Lung Ultrasound (LUS) — Bedside Game-Changer
  • A-lines: normal lung
  • B-lines: interstitial fluid (pulmonary edema, ILD)
  • Consolidation: pneumonia
  • Pleural effusion: anechoic
  • Pneumothorax: lack of pleural sliding
  • Tail of lung sign (M-mode): seashore (normal) vs barcode (pneumothorax)
  • BLUE protocol (Bedside Lung Ultrasound in Emergency)
  • 2024 + ATS/ACEP integration
303.1.0.1.1.7 MRI
  • Less common
  • ILD specific patterns
  • Mediastinal masses
  • Bronchogenic cyst
  • Vascular abnormalities (with MRA)
303.1.0.1.2 Pulmonary Function Tests (PFTs)
303.1.0.1.2.1 Spirometry
  • FVC (forced vital capacity)
  • FEV1 (forced expiratory volume in 1 sec)
  • FEV1/FVC ratio: < 0.7 (or < LLN) = obstruction

Patterns: - Obstructive: ↓ FEV1/FVC (< 0.7) - Severity by FEV1 % predicted (GOLD/ATS) - Asthma, COPD, bronchiectasis, CF - Restrictive: ↓ TLC (< 80%) - With normal FEV1/FVC ratio - ILD, neuromuscular, kyphoscoliosis, obesity - Mixed: ↓ FEV1/FVC + ↓ TLC

303.1.0.1.2.2 Bronchodilator Reversibility
  • After albuterol
  • Improvement: > 12% AND > 200 mL FEV1
  • Asthma reversible; COPD usually not
303.1.0.1.2.3 Methacholine Challenge
  • For asthma diagnosis when spirometry normal
  • Positive: FEV1 drops > 20% at given dose (PC20 ≀ 8 mg/mL)
  • Useful for cough-variant asthma
303.1.0.1.2.4 Lung Volumes (Body Plethysmography or Helium Dilution)
  • TLC (total lung capacity)
  • RV (residual volume)
  • FRC (functional residual capacity)
  • ↑ TLC: emphysema
  • ↓ TLC: restrictive (ILD, NM disease)
303.1.0.1.2.5 Diffusion Capacity (DLCO)
  • CO transfer
  • Adjusted for Hgb
  • ↓ in ILD, emphysema, PH, anemia
  • ↑ in alveolar hemorrhage, polycythemia, asthma, obesity
303.1.0.1.2.6 6-Minute Walk Test (6MWT)
  • Functional capacity
  • Distance, dyspnea (Borg), SpO2
  • < 300 m severely limited
  • Useful: ILD, PAH, COPD, HF, pre-transplant
303.1.0.1.2.7 Cardiopulmonary Exercise Testing (CPET)
  • VO2 max
  • Distinguishes cardiac vs pulmonary
  • Anaerobic threshold
  • Wasserman 9-panel plot
303.1.0.1.3 Bronchoscopy
303.1.0.1.3.1 Flexible Bronchoscopy
  • Diagnostic + therapeutic
  • Direct visualization
  • BAL (bronchoalveolar lavage): infection workup, ILD
  • Brushings + biopsy
  • Transbronchial biopsy (TBLB)
  • Endobronchial ultrasound (EBUS)
303.1.0.1.3.2 Endobronchial Ultrasound (EBUS) / TBNA
  • Mediastinal + hilar lymph nodes
  • NSCLC staging
  • TB, sarcoid diagnosis
  • Real-time imaging + biopsy
303.1.0.1.3.3 Cryobiopsy
  • Larger tissue sample
  • Better for ILD diagnosis
  • Reduced complications vs surgical
303.1.0.1.3.5 Rigid Bronchoscopy
  • Massive hemoptysis
  • Foreign body removal
  • Airway stenting
  • Therapeutic interventions
303.1.0.1.4 Sputum + Pleural Fluid
303.1.0.1.4.1 Sputum
  • Color, volume, consistency
  • Gram stain + culture
  • AFB smear + culture (TB)
  • Cytology
  • PCR (TB, viral, fungal)
  • Eosinophils (eosinophilic bronchitis)
303.1.0.1.4.2 Pleural Fluid (Thoracentesis)
  • Light’s Criteria (Exudate if ≥ 1):
    • Pleural protein / serum protein > 0.5
    • Pleural LDH / serum LDH > 0.6
    • Pleural LDH > 2/3 upper limit of normal serum LDH
  • Cell count + differential
  • Glucose: low in empyema, rheumatoid, malignant
  • pH: < 7.2 in complicated parapneumonic, empyema
  • Amylase: pancreatitis, esophageal rupture
  • Triglycerides: chylothorax (> 110)
  • Cytology: malignancy
  • Culture: bacterial, AFB, fungal
  • ADA (adenosine deaminase) > 40: TB pleurisy
303.1.0.1.5 Biopsy
303.1.0.1.5.1 Transbronchial Biopsy (TBLB)
  • Through bronchoscope
  • Small samples
  • Risk: pneumothorax, bleeding
303.1.0.1.5.2 Cryobiopsy
  • Larger sample
  • Better diagnostic yield for ILD
  • Improved safety profile
303.1.0.1.5.3 Surgical (VATS / Open)
  • Definitive ILD diagnosis (when needed)
  • Sentinel lymph node
  • Wedge resection
303.1.0.1.5.4 Percutaneous CT-Guided
  • Peripheral nodules
  • Risk: pneumothorax (10-30%), hemoptysis
  • For lesions inaccessible by bronchoscopy
303.1.0.1.6 Molecular + Genetic
303.1.0.1.6.1 NSCLC Molecular Profiling (Critical for Therapy)
  • EGFR (15% Asian populations have mutations)
  • ALK rearrangement
  • ROS1 rearrangement
  • KRAS G12C (sotorasib, adagrasib targets)
  • MET exon 14
  • HER2
  • BRAF V600E
  • NTRK fusion
  • PD-L1 expression (immunotherapy)
  • TMB (tumor mutational burden)
303.1.0.1.6.2 Liquid Biopsy (ctDNA)
  • Plasma cell-free DNA
  • Non-invasive
  • Useful for monitoring + resistance mutations
  • Less sensitive than tissue but improving
303.1.0.1.6.3 Single-Cell + Spatial Transcriptomics
  • Research / emerging
  • Lung cancer subtyping
  • Immune microenvironment
303.1.0.1.7 Sleep Studies
303.1.0.1.7.1 Polysomnography (PSG) — Gold Standard
  • EEG, ECG, EMG, EOG, respiratory effort, airflow, SpO2
  • In-lab overnight
  • AHI calculation
  • Diagnose: OSA, central sleep apnea, periodic limb movements
303.1.0.1.7.2 Home Sleep Apnea Test (HSAT)
  • Limited channels
  • Convenient
  • For uncomplicated OSA suspicion
  • Less sensitive than in-lab
303.1.0.1.8 Specialized Tests
303.1.0.1.8.1 Bronchial Provocation
  • Methacholine challenge (asthma)
  • Mannitol challenge
  • Exercise challenge
  • Aspirin challenge (NSAID-exacerbated respiratory disease)
303.1.0.1.8.2 Allergy Testing
  • Skin prick test
  • Specific IgE
  • For allergic asthma identification
303.1.0.1.8.3 Eosinophil Markers
  • Blood eosinophilia (predictive in biologic response)
  • FeNO (fractional exhaled nitric oxide)
  • Sputum eosinophils
303.1.0.1.8.4 Exhaled Breath Analysis
  • VOCs (volatile organic compounds)
  • Emerging diagnostic
  • COVID-19 detection in trials

303.1.0.2 🩺 床邊速查

  • CXR: first-line
  • HRCT: ILD gold standard; bronchiectasis, emphysema, ground-glass
  • CTPA: PE gold standard
  • LUS: bedside game-changer (A-line, B-line, sliding, M-mode)
  • PFT: obstructive (↓ FEV1/FVC) vs restrictive (↓ TLC) vs mixed
  • Methacholine challenge: asthma confirmation
  • EBUS: mediastinal LN sampling
  • Cryobiopsy / robotic bronchoscopy: peripheral lesions
  • Light’s criteria: pleural exudate vs transudate
  • NSCLC mol profile: EGFR/ALK/ROS1/KRAS G12C/MET/BRAF/NTRK/PD-L1