What are the acceptable average and high average leak rates on a Luna (Positive Airway Pressure) device?

Acceptable Leak Rates for Luna Positive Airway Pressure Devices

For Luna PAP devices, the acceptable average leak is less than 24 L/min with a nasal interface and less than 36 L/min with a full face interface, while high average leak should not exceed these thresholds. 1

Understanding Leak Measurements on PAP Devices

The American Thoracic Society provides specific guidance on leak measurements for different PAP device manufacturers:

• Luna devices (manufactured by 3B Medical) follow similar standards to ResMed devices, which measure unintentional leak (total flow minus intentional leak)
• Acceptable leak thresholds are defined as:
  • < 24 L/min with nasal interfaces
  • < 36 L/min with full face/oronasal interfaces 1

Types of Leaks in PAP Therapy

It's important to distinguish between two types of leaks:

• Intentional leak: Designed into the mask system through vent holes to flush out exhaled CO2
• Unintentional leak: Occurs around mask edges or through the mouth (with nasal masks)

The Luna device, like other modern PAP machines, reports unintentional leak by subtracting the known intentional leak from the total measured flow 1, 2.

Clinical Significance of Leak Values

Monitoring leak trends is often more informative than focusing on absolute values:

• A sudden increase in leak without pressure changes suggests development of unintentional leak
• Persistent high leaks can:
  • Compromise therapy effectiveness
  • Reduce the ability of pressure support to augment tidal volume
  • Cause arousals and sleep fragmentation
  • Lead to dry mouth symptoms 2

Managing Excessive Leaks

When leaks exceed acceptable thresholds:

1. First-line approach: Mask refit or readjustment 1, 2
2. For persistent leaks: Consider changing mask type
3. For mouth leaks with nasal interface: Add chin strap or switch to full face mask
4. For BiPAP users: Consider adjusting pressure differential if clinically appropriate 2

Monitoring Best Practices

• Check leak values as part of routine PAP therapy follow-up
• Pay attention to leak trends rather than isolated high readings
• Consider the impact of leaks on other therapy parameters (AHI, oxygen saturation)
• Ensure adequate humidification, as high leaks can increase dry mouth symptoms 2

Caveats and Considerations

• Leak thresholds may vary slightly between different Luna device models
• Manufacturer specifications should always be consulted for the specific device being used
• Some patients may tolerate higher leak levels without clinical consequences
• The impact of leaks on therapy effectiveness should be evaluated alongside clinical symptoms and therapy outcomes 1, 2