Would decreasing the delta pressure on BiPAP (Bilevel Positive Airway Pressure) decrease leakage?

Managing BiPAP Leakage by Decreasing Delta Pressure

Yes, decreasing the delta pressure (the difference between IPAP and EPAP) on BiPAP can help reduce unintentional leakage, particularly when mask or mouth leaks are causing significant issues with therapy effectiveness.

Understanding BiPAP Leakage

BiPAP therapy involves two pressure levels:

• Inspiratory Positive Airway Pressure (IPAP)
• Expiratory Positive Airway Pressure (EPAP)
• The difference between these (IPAP-EPAP) is the delta pressure

Types of Leaks

1. Intentional leak: Controlled leak from mask ports that washes out CO2
2. Unintentional leak:
   • Mask leak (between mask and face)
   • Mouth leak (air escaping through mouth with nasal mask)

How Delta Pressure Affects Leakage

Higher pressure differences between IPAP and EPAP can increase the likelihood of unintentional leaks for several reasons:

• Higher IPAP creates greater pressure against mask seals
• Greater pressure differential increases the force pushing air through any potential leak points
• A study examining BiPAP therapy showed that minimizing leak improved oxygenation, decreased arousal index, and increased REM sleep 1

Algorithm for Managing BiPAP Leaks

1. First, attempt mask refit or adjustment

   • The American Academy of Sleep Medicine recommends mask refit or readjustment whenever significant unintentional leak is observed 1
   • This is the first-line approach before changing pressure settings

2. If leaks persist despite proper mask fit:

   • Consider decreasing delta pressure by:
     • Reducing IPAP while maintaining adequate ventilation
     • Slightly increasing EPAP if clinically appropriate
     • Maintaining an effective but smaller pressure differential

3. For mouth leaks with nasal mask:

   • Add a chin strap to reduce mouth opening
   • Consider switching to a full-face/oronasal mask 1

4. For patient comfort issues:

   • Use pressure relief during EPAP (flexible PAP) if the patient complains of difficulty exhaling 1
   • Adjust rise time (time for pressure change from EPAP to IPAP) for comfort 1

Monitoring Effectiveness

When adjusting delta pressure to reduce leaks, ensure:

• Respiratory disturbance index (RDI) remains <5 per hour for optimal titration 1
• Minimum sea level SpO2 stays above 90% 1
• Patient comfort is maintained to ensure adherence

Pitfalls and Caveats

1. Don't sacrifice therapeutic effectiveness

   • Reducing delta pressure too much may compromise ventilation
   • The primary goal remains control of obstructive respiration with a low RDI 1

2. Recognize normal vs. problematic leaks

   • Some level of leak is expected and acceptable
   • An unacceptable leak is substantially higher than the leak recorded from a well-fitted interface at the same pressure 1

3. Consider leak trends rather than absolute values

   • A sudden increase in leak without pressure change suggests mask/mouth leak 1
   • Different interfaces have different expected leak profiles

4. Be aware of humidification needs

   • Leaks can increase dry mouth symptoms
   • Adding heated humidification may improve comfort and reduce leak-related symptoms 2

By systematically addressing BiPAP leakage through appropriate mask fitting and careful adjustment of delta pressure, you can improve therapy effectiveness, patient comfort, and ultimately treatment outcomes.