Management

• Address hypoxemia

• Apply lung-protective ventilation strategies.

• Augment therapy as needed based on severity (see the Berlin criteria for ARDS).

  • Moderate-severe ARDS: Apply prone positioning, lung recruitment maneuvers; consider neuromuscular blockade.

  • Severe ARDS refractory to therapy: Consider indications for ECMO.

• Identify and treat the underlying cause (e.g., pneumonia, pancreatitis, sepsis).

The foundation of management in all patients with ARDS consists of treating hypoxemia, lung-protective ventilation (to minimize further lung damage), treatment of the underlying cause, and supportive care.

• Oxygenation: Hypoxemia is a hallmark feature of ARDS and should be addressed immediately.

• Lung-protective ventilation: All patients with ARDS should be treated with lung-protective ventilation to decrease the risk of VILI. [9]

  • General initial settings include:

    • Low tidal volume (Vt 6–8 mL/kg) : prevents alveolar distention

    • Low plateau pressure (PPlat ≤ 30 cm H2O): prevents barotrauma

    • PEEP > 5 cm H2O: allows for alveolar recruitment

  • Allow for permissive hypercapnia

  • PEEP and FiO2 can be adjusted to recruit collapsed alveoli and improve oxygenation.

    • Oxygenation goal: PaO2 55–80 mm Hg or SpO2 88–95%

    • Avoid oxygen toxicity: use lowest FiO2 possible

  • See lung-protective ventilation strategy for more information and specific parameter settings.

  • See also “Intensive care” in “COVID-19.”

• Supportive care

  • Conservative fluid management

  • Consider furosemide for volume overload.

  • VTE prophylaxis

  • Optimize nutrition.

  • Consider stress ulcer prophylaxis

Prone positioning

• Effects

  • Reduces V/Q mismatch from dependent atelectasis

  • Increases lung compliance

• Indications

  • P/F ratio < 150 mm Hg

  • Pulmonary edema

Lung recruitment maneuvers

• Definition: a series of treatment measures that increase the surface area of lung available for gas exchange

• Methods

  • Sustained inflation techniques (e.g., increasing airway pressure to 30–40 cm H2O for 30–40 seconds followed by a decrease in PEEP)

  • Incremental PEEP increase

• Neuromuscular blockade

  • Consider within the first 48 hours for patients with P/F ratio < 150 mm Hg and/or severe patient-ventilator dyssynchrony. [14]

• Corticosteroids: Consider in early ARDS

The following interventions should only be considered with expert consultation and when guideline-recommended treatments have failed.

• Consider alternative ventilator settings (e.g., mode, parameters, or overall strategy): See mechanical ventilation.

• Consider experimental therapies (e.g., inhaled vasodilators such as nitric oxide or prostacyclin).

• ECMO: method of supporting the O2/CO2 exchange through the use of artificial lung membranes

• Disease course

  • Most patients begin to improve after the first 1–3 weeks and symptoms usually resolve fully.

  • Some develop interstitial pulmonary fibrosis with prolonged ventilator dependence and restrictive lung disease.

• In patients with simultaneous multiorgan failure, the mortality rate is 30–50%.