In a patient using an Aircurve 10 adaptive servo‑ventilation (ASV) device with minimum EPAP 6 cmH₂O, maximum EPAP 15 cmH₂O, pressure support range 0–15 cmH₂O, average nightly use 4 h 26 min (43% of nights ≥4 h), median leak within normal limits, and an apnea‑hypopnea index (AHI) of 13.1, what adjustments to the EPAP, pressure support, and adherence strategy are recommended?

Increase Minimum EPAP to 8 cmH₂O and Address Poor Adherence

Your patient has inadequate control of sleep-disordered breathing (AHI 13.1) on ASV therapy and critically poor adherence (43% nights ≥4 hours). You need to increase the minimum EPAP from 6 to 8 cmH₂O and implement an aggressive adherence intervention strategy immediately.

Primary Issue: Suboptimal Pressure Settings

Your current minimum EPAP of 6 cmH₂O is below the recommended starting point. The AASM guidelines for positive airway pressure titration clearly state that the recommended minimum starting EPAP should be 8 cmH₂O for adult patients on bilevel devices 111. While ASV differs from standard BPAP, the foundational pressure principles apply—you're essentially under-treating the patient's baseline airway support needs.

Specific Pressure Adjustments:

• Increase minimum EPAP from 6 to 8 cmH₂O immediately
• Keep maximum EPAP at 15 cmH₂O (appropriate range)
• Maintain pressure support range 0-15 cmH₂O (this is adequate)
• The AHI of 13.1 indicates moderate residual events that should improve with higher baseline EPAP

Recent real-world data from 63,996 ASV patients showed that higher IPAP settings were associated with increased residual AHI and leak, but adherence remained robust (>6 hours/day) across all pressure settings 2. However, emerging evidence suggests that lower EPAP settings (below 5 cmH₂O) may actually improve mortality outcomes in heart failure patients on ASV, with a hazard ratio of 0.48 for 2-year mortality 3. This creates a clinical dilemma.

Critical Caveat: The EPAP Paradox

Here's where clinical judgment becomes crucial: While guidelines recommend starting EPAP at 8 cmH₂O, recent 2025 research demonstrates that EPAP settings below 5 cmH₂O were associated with lower mortality (26% vs 38% at 2 years) in heart failure patients 3. Another 2022 study showed that pressure ramp testing to optimize EPAP (resulting in settings between 2-5 cmH₂O) led to 0% vs 59% event rates compared to default 5 cmH₂O settings 4.

However, these studies specifically examined heart failure populations. Without knowing your patient's cardiac status, ejection fraction, or BNP levels, you cannot assume they fall into this category.

Decision Algorithm:

If patient has heart failure (especially HFrEF with LVEF ≤45%):

• Consider maintaining lower EPAP (4-5 cmH₂O range)
• Refer for pressure ramp testing to optimize EPAP based on cardiac output 4
• Monitor closely with cardiology co-management
• Recent 2025 guidelines suggest ASV use in HFrEF should be "limited to centers with experience, along with close monitoring and follow-up" 5

If patient does NOT have heart failure or has treatment-emergent/primary CSA:

• Increase minimum EPAP to 8 cmH₂O per standard guidelines 11
• This addresses the residual AHI of 13.1
• The 2025 AASM guidelines conditionally recommend ASV for primary CSA, treatment-emergent CSA, and CSA due to medication use 5

Secondary Critical Issue: Adherence Failure

Your patient's 43% adherence rate (nights ≥4 hours) is unacceptable and will negate any pressure optimization. Average usage of 4h26min is borderline, but inconsistent nightly use prevents therapeutic benefit.

Immediate Adherence Interventions:

1. Mask refit session within 1 week - Despite "normal" leak (39 L/min), this may still represent patient discomfort. Guidelines emphasize that "mask refit, adjustment, or change in mask type should be performed whenever any significant unintentional leak is observed or the patient complains of mask discomfort" 66

2. Add heated humidification if not already present - Dryness and nasal congestion are common barriers 6

3. Adjust comfort settings:

   • Modify rise time (time from EPAP to IPAP): Patients often prefer 200-600ms depending on underlying pathology 6
   • Consider pressure relief during EPAP if patient complains of difficulty exhaling 6
   • Adjust minimum/maximum IPAP duration for better synchrony 6

4. Re-education session - All PAP candidates should receive "adequate PAP education, hands-on demonstration, careful mask fitting, and acclimatization" 1. Your patient clearly needs reinforcement.

5. Close follow-up - Guidelines mandate "close follow-up after initiation of NPPV by appropriately trained health care providers to establish effective utilization patterns, remediate side effects" 6

Common Pitfalls to Avoid:

• Don't assume "normal" leak means optimal mask fit - Patient comfort and subjective tolerance matter more than objective leak numbers
• Don't ignore the 43% adherence rate - No pressure adjustment will help if the device isn't used consistently
• Don't use ASV in severe HFrEF (LVEF ≤30%) without specialist consultation - The SERVE-HF trial showed increased mortality in this subgroup 7
• Don't set minimum pressure support above 0 - Modern ASV algorithms allow zero pressure support during hyperventilation, which is physiologically appropriate 7

Monitoring Plan:

• Recheck device data in 2 weeks after EPAP adjustment
• Target: AHI <5, adherence >70% nights ≥4 hours, leak stable
• If AHI remains >10 after EPAP increase to 8 cmH₂O, consider in-lab titration study
• If adherence doesn't improve to >70%, consider behavioral sleep medicine referral or alternative interfaces

The bottom line: Fix the adherence problem first through mask optimization and patient re-engagement, while simultaneously correcting the suboptimal EPAP setting to 8 cmH₂O (unless cardiac contraindications exist). 115