Updated: 10/4/2016

Adult Respiratory Distress Syndrome

Review Topic
  • Acute Respiratory Distress Syndrome (ARDS) results from acute lung injury that leads to 
    • non-cardiogenic pulmonary edema
    • respiratory distress
    • refractory hypoxemia
    • decreased lung compliance
  • Etiology
    • acute endothelial damage resulting from
      • aspiration
      • infection
      • pancreatitis
      • multiple blood transfusions
      • lung injury
      • sepsis or shock
      • major trauma
      • large surface area burns
      • fat emboli
      • thromboembolism
      • multi-system organ failure
  • Prognosis
    • high mortality rate (50% overall) is associated with ARDS even in setting of ICU
  • ARDS is represented by three phases

    Exudative phase initially hyaline membrane comprised of fibrin form
    Proliferative phase 3 days alveolar exudate resolves or organizes
    Fibrotic phase 3-4 weeks alveolar ducts and spaces undergo fibrosis
  • Symptoms
    • acute onset (12-48 hours) of
      • dyspnea
      • fever
      • mottled or cyanotic skin
  • Physical exam
    • resistant hypoxia
    • intercostal retractions
    • rales/crackles and ronchi
    • tachypnea
  • Hypoxemia is refractory to O2
    • 3 different categories of ARDS based on degree of hypoxemia
    • PaO2 / FIO2 ratio < 300 mm Hg=  mild
    • PaO2 / FIO2 ratio < 200 mm Hg=  moderate
    • PaO2 / FIO2 ratio < 100 mm Hg=  severe
  • Chest xray 
    • shows patchy pulmonary edema (air space disease)
    • diffuse bilateral pulmonary infiltrates
      • normal sized heart
        • makes CHF less likely
  • Respiratory compliance (<40 mL/cm H20)
  • Positive end-expiratory pressure (>10cm H20)
  • Corrected expired volume per minute (>10L/min)
  • Cardiogenic pulmonary edema (i.e. CHF or MI), bilateral pneumonia, SARS
  • Nonoperative
    • PEEP ventilation and steroids
    • treat the underlying pathology/disease
  • Operative
    • early stabilization of long bone fractures (femur)
  • Prevention
    • closely monitor PEEP in patients at-risk of ARDS
    • serial X-rays in concerning patients can assist in early identification and intervention
  • Pneumothorax
    • secondary to ventilator with high PEEP

Please rate topic.

Average 3.3 of 33 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (1)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Topic COMMENTS (8)
Private Note