For a 50‑kg woman with severe ARDS who has received lung‑protective ventilation (tidal volume 6 ml/kg) and seven 18‑hour prone positioning sessions without oxygenation improvement, now tracheostomized with sedation stopped and spontaneous breathing but persistent hypoxia and tachypnea, should I initiate airway‑pressure‑release ventilation (APRV)?

Should You Use APRV Mode in This Patient?

No, you should not routinely switch to APRV mode for this patient with severe ARDS. The major ARDS guidelines do not recommend APRV as a standard ventilation mode, and you should instead optimize your current lung-protective ventilation strategy with higher PEEP and consider resuming prone positioning despite the tracheostomy 1.

Why APRV Is Not Recommended

The 2017 ATS/ERS/SCCM clinical practice guidelines for ARDS mechanical ventilation do not include APRV among recommended ventilation strategies 1. In fact, one review explicitly states that "airway pressure release ventilation...are not recommended therapies" for ARDS 2. The absence of APRV from major guidelines reflects the lack of high-quality evidence demonstrating mortality benefit or improved patient-centered outcomes.

What You Should Do Instead

Continue Lung-Protective Ventilation

You are correctly using:

• Tidal volume 6 ml/kg predicted body weight (280 ml for 50 kg)
• This is the strong recommendation for all ARDS patients 1
• Maintain plateau pressure ≤30 cm H2O

Optimize PEEP Strategy

For your patient with severe ARDS (given the lack of response to proning and persistent hypoxemia):

• Use higher PEEP levels - this is a conditional recommendation specifically for moderate-to-severe ARDS 1
• The guidelines show that higher PEEP (mean ~15 cm H2O vs ~9 cm H2O) reduces mortality in patients with PaO2/FiO2 <200 1
• Titrate PEEP upward while monitoring plateau pressure and hemodynamics

Consider Resuming Prone Positioning

This is critical and often overlooked: The tracheostomy does not contraindicate prone positioning.

• Prone positioning has a strong recommendation for severe ARDS, with sessions >12 hours/day 1
• The mortality benefit (RR 0.74) is substantial in severe ARDS 1, 3
• Tracheostomized patients can be safely proned - the tracheostomy tube may actually make airway management easier during proning 3
• Your patient's lack of response to previous proning cycles may have been due to insufficient duration or other factors, but the evidence supports continued use

Address Spontaneous Breathing Carefully

Now that sedation is stopped and she has spontaneous breathing:

• Ensure respiratory drive is not excessive (avoid patient self-inflicted lung injury)
• If tachypnea and hypoxia persist, consider:
  • Pressure support ventilation (PSV) or SIMV modes that maintain lung-protective parameters
  • Light sedation to reduce respiratory drive if work of breathing is excessive
  • Do not abandon lung-protective tidal volumes even with spontaneous breathing

Additional Considerations for Refractory Hypoxemia

If optimizing PEEP and resuming prone positioning fail:

• Recruitment maneuvers: Conditional recommendation for moderate-to-severe ARDS 1
• Neuromuscular blockade: May be considered for severe ARDS with refractory hypoxemia 4, 5
• Corticosteroids: Should be considered within 14 days of ARDS onset for moderate-to-severe cases 5
• ECMO: Consider transfer to an ECMO center if she remains refractory to all conventional therapies 1, 5

Common Pitfalls to Avoid

1. Don't abandon proven strategies: The lack of response to proning doesn't mean it won't work with optimization or that APRV is the answer
2. Don't allow high tidal volumes: Even with spontaneous breathing, maintain lung-protective parameters
3. Don't forget driving pressure: Target driving pressure (plateau pressure - PEEP) <15 cm H2O 5
4. Don't overlook fluid management: Aim for neutral-to-negative fluid balance if hemodynamically stable 5

The Bottom Line

APRV lacks guideline support and high-quality evidence for ARDS management. Your patient needs optimization of evidence-based therapies: higher PEEP for severe ARDS, consideration of resuming prone positioning (which works even post-tracheostomy), and careful management of spontaneous breathing to maintain lung protection. If these fail, escalate to recruitment maneuvers, neuromuscular blockade, or ECMO rather than switching to unproven modes like APRV.