What is the best ventilator recruitment strategy for a patient with acute respiratory distress syndrome (ARDS) or severe respiratory failure?

Ventilator Recruitment Strategy for ARDS

For patients with moderate to severe ARDS, use higher PEEP without prolonged lung recruitment maneuvers, and avoid routine prolonged recruitment maneuvers entirely. 1

Core Ventilation Strategy

All ARDS patients require lung-protective ventilation as the foundation:

• Tidal volume: 4-8 mL/kg predicted body weight 1
• Plateau pressure: ≤30 cmH₂O 1
• Target driving pressure (plateau pressure - PEEP): ≤15 cmH₂O 2

These parameters take absolute priority over recruitment strategies. 1

PEEP Strategy by ARDS Severity

Mild ARDS (PaO₂/FiO₂ 200-300 mmHg)

• Use lower PEEP levels (typically 8-10 cmH₂O) 3
• Higher PEEP may be harmful in this population 3

Moderate to Severe ARDS (PaO₂/FiO₂ ≤200 mmHg)

• Use higher PEEP (typically 13-18 cmH₂O or higher) 1, 3
• Titrate PEEP to maximize alveolar recruitment while avoiding overdistention 3
• The 2024 ATS guideline provides a conditional recommendation for higher PEEP in this population 1

Recruitment Maneuvers: Critical Update

The evidence has shifted dramatically against prolonged recruitment maneuvers:

• Strong recommendation AGAINST prolonged lung recruitment maneuvers in moderate to severe ARDS (moderate certainty of evidence) 1
• The 2017 guideline gave only conditional support for recruitment maneuvers with low confidence 1
• The 2024 update strengthened this to a strong recommendation against their routine use 1

If Recruitment Maneuvers Are Considered (Not Recommended)

Only in refractory hypoxemia despite optimal PEEP and prone positioning:

• Brief maneuvers only (not prolonged) 1
• Sustained inflation to 40 cmH₂O for 40 seconds has been described, but this approach is no longer recommended based on current evidence 4
• Monitor closely for hemodynamic compromise and barotrauma 1

Adjunctive Strategies for Severe ARDS (PaO₂/FiO₂ <100 mmHg)

Prone Positioning (First-Line)

• Strong recommendation for prone positioning >12 hours daily in severe ARDS 1
• This has the strongest mortality benefit of any adjunctive therapy 1
• Implement early, not as rescue therapy 5, 6

Neuromuscular Blockade

• Conditional recommendation for neuromuscular blocking agents in early severe ARDS 1
• Consider for ≤48 hours when PaO₂/FiO₂ <150 mmHg 1
• Particularly useful for ventilator-patient dyssynchrony 6

Corticosteroids

• Conditional recommendation for corticosteroids in ARDS (moderate certainty of evidence) 1
• This represents new evidence since the 2017 guideline 1

VV-ECMO

• Conditional recommendation for VV-ECMO in selected patients with severe ARDS who fail conventional management 1
• Only at centers with ECMO expertise 6
• Consider when reversible disease is present 6

Fluid Management

• Conservative fluid strategy for established ARDS without tissue hypoperfusion 1
• Avoid fluid overload, which worsens pulmonary edema and promotes right ventricular failure 5, 6

Common Pitfalls to Avoid

• Do not use prolonged recruitment maneuvers routinely - the 2024 guideline provides a strong recommendation against this practice 1
• Do not use high-frequency oscillatory ventilation - strong recommendation against routine use 1
• Do not delay prone positioning in severe ARDS - implement early, not as rescue 5
• Do not apply higher PEEP to mild ARDS - this may worsen outcomes 3
• Do not use recruitment maneuvers as a substitute for adequate PEEP - PEEP is the primary strategy for maintaining recruitment 1

Monitoring Requirements

• Continuous oxygen saturation (target SpO₂ 88-95%, not >96%) 6
• Respiratory mechanics (plateau pressure, driving pressure) 2, 6
• Hemodynamics and right ventricular function via echocardiography 5, 6
• Assess for ventilator-patient dyssynchrony 6

Key Evidence Evolution

The most important change from 2017 to 2024 guidelines is the strengthening of the recommendation against prolonged recruitment maneuvers from conditional (low confidence) to strong (moderate certainty). 1 This reflects accumulating evidence that prolonged recruitment maneuvers do not improve outcomes and may cause harm. The focus has shifted to optimizing PEEP, prone positioning, and other adjunctive therapies rather than aggressive recruitment strategies. 1