315.2 🩺 國考版

315.2.1 高頻考點

315.2.1.1 Respiratory Failure

  • Type I: hypoxemic (PaO2 < 60)
  • Type II: hypercapnic (PaCO2 > 45)

315.2.1.2 ARDS Berlin Definition (2012)

  • Within 1 week of insult
  • Bilateral opacities
  • Not solely cardiac
  • PaO2/FiO2 < 300 with PEEP ≥ 5

315.2.1.3 ARDS Severity

  • Mild: 200-300
  • Moderate: 100-200
  • Severe: ≀ 100

315.2.1.4 ARDS Etiology

  • Direct: pneumonia, aspiration, contusion, inhalation
  • Indirect: sepsis (most), trauma, pancreatitis, TRALI

315.2.1.5 Lung-Protective Ventilation

  • Tidal volume 6 mL/kg PBW
  • Plateau pressure < 30
  • Driving pressure < 15
  • Permissive hypercapnia (pH > 7.20 OK)

315.2.1.6 Key Trials

  • ARMA / ARDSnet (2000): 6 mL/kg vs 12 mL/kg → ↓ mortality 9%
  • PROSEVA (2013): prone for severe ARDS → ↓ mortality 16%
  • ACURASYS (2010): cisatracurium in severe ARDS → ↑ survival
  • ROSE (2019): early NMB no benefit with better sedation
  • FACTT (2006): conservative fluid → ↑ ventilator-free days
  • CESAR (2009), EOLIA (2018): ECMO benefit suggested
  • RECOVERY (2020): dexamethasone in COVID → ↓ mortality
  • REMAP-CAP: tocilizumab in severe COVID

315.2.1.7 Steroids in ARDS

  • Non-COVID: methylprednisolone or dexamethasone (DEXA-ARDS) — improved outcomes
  • COVID-19: dexamethasone 6 mg × 10 days (RECOVERY)

315.2.1.8 Subphenotypes (Calfee)

  • Hyperinflammatory (worse, ↑ IL-6/IL-8/TNF)
  • Hypoinflammatory (better)

315.2.2 易混淆比范

Type Mechanism Examples Treatment
I (hypoxemic) V/Q mismatch / shunt ARDS, pneumonia, PE O2, NIV, ventilation, prone, ECMO
II (hypercapnic) Alveolar hypoventilation COPD, NM, drug OD NIV, address cause
III (perioperative) Atelectasis Post-op PEEP, mobilization
IV (shock) Hypoperfusion Sepsis, MI shock Address shock

315.2.3 Special Topics

315.2.3.1 Driving Pressure (Amato 2015)

  • Plateau - PEEP
  • < 15 cm H2O = best survival
  • More predictive than Vt or plateau alone
  • Reduce by ↓ Vt or ↑ PEEP

315.2.3.2 Prone Positioning Mechanics

  • Improves V/Q matching
  • Reduces dorsal atelectasis
  • Reduces chest wall + diaphragm restriction
  • 16+ hours/day in severe ARDS

315.2.3.3 ECMO Indications + Contraindications

  • Indications: PaO2/FiO2 < 80, pH < 7.20, plateau > 30
  • Contraindications: irreversible disease, severe comorbidity, > 7 days mechanical ventilation, severe immunosuppression
  • Multidisciplinary decision