Increase Your Minimum Pressure Setting
If you're feeling insufficient airflow with EPR level 3 on your ResMed AirSense 11 APAP, you should increase your minimum pressure by 2-3 cm H₂O increments, as EPR effectively reduces your expiratory pressure by 3 cm H₂O, which may be leaving your therapeutic pressure inadequate.
Understanding the Problem with EPR Level 3
EPR (Expiratory Pressure Relief) on level 3 reduces your expiratory pressure by 3 cm H₂O. Research demonstrates that pressure-relief features like EPR can actually impair CPAP efficacy if the therapeutic pressure isn't adjusted upward to compensate 1. When EPR 3 is activated, the device delivers 2.6 cm H₂O lower mean pressure than conventional CPAP, which can fail to normalize breathing and control obstructive events 1.
The core issue: If your minimum pressure is set at the standard 4 cm H₂O (as recommended by AASM guidelines 2), EPR 3 effectively drops your expiratory pressure to just 1 cm H₂O during exhalation—far too low to maintain airway patency.
How to Adjust Your Settings
Step 1: Increase Minimum Pressure
- Raise your minimum pressure by at least 3 cm H₂O to compensate for the EPR reduction
- If currently at 4 cm H₂O minimum, increase to 7-8 cm H₂O minimum
- AASM guidelines support pressure increases of 1-2 cm H₂O increments every 5 minutes during titration 2
- Maximum pressure can remain at 20 cm H₂O (standard maximum for adults ≥12 years) 2
Step 2: Monitor Your Response Over 3-5 Nights
- Check your device's data for residual apneas, hypopneas, and leak
- Assess subjective improvement in air hunger sensation
- If still inadequate after 3-5 nights, increase minimum pressure by another 1-2 cm H₂O
Step 3: Alternative Approach if Pressure Increases Don't Help
If raising minimum pressure to 8-10 cm H₂O still leaves you feeling air-starved:
- Reduce EPR to level 1 or 2 instead of level 3
- This provides some expiratory relief (1-2 cm H₂O reduction) while maintaining higher therapeutic pressure
- Studies show patient satisfaction can be maintained with lower EPR settings while improving efficacy 3
Critical Pitfall to Avoid
Do not simply increase EPR or add more pressure relief thinking it will give you more air. This is counterintuitive but important: EPR reduces pressure during exhalation, which can paradoxically worsen your sensation of insufficient airflow if your baseline therapeutic pressure is too low. The solution is higher baseline pressure, not more pressure relief 1, 4.
Why This Happens
The sensation of "not enough air" with high EPR typically indicates one of two problems:
- Your therapeutic pressure requirement is higher than your current minimum setting, and EPR 3 is dropping you below the threshold needed to maintain airway patency
- Residual flow limitation is occurring despite the APAP algorithm, which EPR can worsen by reducing mean delivered pressure 1
Clinical data shows that 83.5% of patients with pressure intolerance and PAP failure benefited from pressure mode changes, and 96.7% improved with pressure setting adjustments 4. Your situation—feeling insufficient airflow—suggests your settings need optimization rather than abandoning the therapy.
When to Consider Switching Modes
If after optimizing your minimum pressure (8-10 cm H₂O) and adjusting EPR (levels 1-2) you still experience discomfort or inadequate airflow, AASM guidelines recommend considering bilevel PAP (BPAP) 2. However, this should be a last resort, as CPAP/APAP with properly adjusted settings resolves most pressure intolerance issues 5, 4.
The key principle: Pressure relief features must be enabled BEFORE initial pressure titration, or therapeutic pressure must be increased to compensate for their activation 1. Since you've already activated EPR 3, you need to increase your minimum pressure accordingly.