👤 By the CinnaRN Clinical Content Team🕐 Updated 2026-08-23🏷️ Physiological Adaptation🔖 Free to read, print, and share
Also known as: acute respiratory distress syndrome · shock lung · wet lung · noncardiogenic pulmonary edema
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Use this quick-reference guide to spot, treat, and prevent ARDS on the NCLEX. Keep it handy during review and on exam day!
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📒 The 1-minute cheat sheet
🩺 Signs
Severe dyspnea, ↓ O₂ despite O₂
Tachypnea, retractions, anxiety
Bilateral infiltrates (white-out)
🧪 Labs
PaO₂/FiO₂ ratio < 300
Resp acidosis, low PaO₂
✅ Do
Intubate + mech ventilation
PEEP, low tidal volume
Prone positioning, treat cause
⚠️ Causes
Sepsis, aspiration, trauma
📚 ARDS — full study notes
The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.
Acute respiratory distress syndrome is a severe inflammatory lung injury causing increased alveolar-capillary permeability, noncardiogenic pulmonary edema, and collapse of the alveoli, leading to refractory hypoxemia. It develops 12 to 48 hours after an insult such as sepsis, aspiration, trauma, or pancreatitis. The hallmark is hypoxemia that does not improve with supplemental oxygen.
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Key points
Understand these first
Refractory hypoxemia that does not respond to increasing oxygen is the defining feature.
Severe dyspnea, tachypnea, and use of accessory muscles develop rapidly.
Chest x-ray shows bilateral diffuse white-out infiltrates with no cardiac cause.
Decreased lung compliance makes the lungs stiff and hard to ventilate.
Pulmonary capillary wedge pressure is normal or low, distinguishing it from cardiogenic pulmonary edema.
ARDS commonly progresses to multi-organ dysfunction and carries high mortality.
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Nursing priorities
What to do, in order
Support oxygenation and prepare for intubation and mechanical ventilation with PEEP.
Use low tidal volume lung-protective ventilation to prevent further barotrauma.
Consider prone positioning to improve oxygenation and ventilation-perfusion matching.
Treat the underlying cause, such as sepsis or aspiration, aggressively.
Monitor ABGs, hemodynamics, and oxygenation continuously, and provide sedation as needed.
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Red flags — report now
Escalate immediately
Worsening hypoxemia despite high FiO2 and PEEP indicates deterioration toward failure.
Sudden drop in oxygen saturation or chest asymmetry on a ventilator may signal pneumothorax from barotrauma.
ABG: severe hypoxemia with PaO2/FiO2 ratio <300 (mild) to <100 (severe)
Refractory hypoxemia: low PaO2 despite high oxygen
PCWP normal or low (<18 mmHg), unlike cardiogenic edema
❓ ARDS: NCLEX FAQs
What are the priority nursing interventions for ARDS?
Support oxygenation and prepare for intubation and mechanical ventilation with PEEP. Use low tidal volume lung-protective ventilation to prevent further barotrauma. Consider prone positioning to improve oxygenation and ventilation-perfusion matching. Treat the underlying cause, such as sepsis or aspiration, aggressively.
What are the warning signs of ARDS a nurse must report?
Worsening hypoxemia despite high FiO2 and PEEP indicates deterioration toward failure. Sudden drop in oxygen saturation or chest asymmetry on a ventilator may signal pneumothorax from barotrauma. Signs of multi-organ failure (oliguria, hypotension, altered mentation) require immediate escalation.
What do I need to know about ARDS for the NCLEX?
Refractory hypoxemia that does not respond to increasing oxygen is the defining feature. Severe dyspnea, tachypnea, and use of accessory muscles develop rapidly. Chest x-ray shows bilateral diffuse white-out infiltrates with no cardiac cause. Decreased lung compliance makes the lungs stiff and hard to ventilate.
What lab values are associated with ARDS?
ABG: severe hypoxemia with PaO2/FiO2 ratio <300 (mild) to <100 (severe). Refractory hypoxemia: low PaO2 despite high oxygen. PCWP normal or low (<18 mmHg), unlike cardiogenic edema.
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Quick Tip
Refractory hypoxemia that does not respond to increasing oxygen is the defining feature.