Flutter Valve vs PEP Device: They Are Related But Not Identical
No, a flutter valve is not the same as a PEP device—the flutter is a specific type of oscillating PEP (OPEP) device, which is a subcategory within the broader family of PEP devices.
Understanding the Distinction
PEP Devices (Positive Expiratory Pressure)
PEP devices create resistance during exhalation, generating positive pressure in the airways without oscillation. These include:
- Standard PEP masks
- Threshold PEP devices
- Non-oscillating resistance valves
Flutter Valve (Oscillating PEP)
The Flutter is a gravity-dependent oscillating PEP device that contains a steel ball inside a cone that vibrates during exhalation, creating both positive expiratory pressure AND oscillations 1. This dual mechanism distinguishes it from simple PEP devices.
Key Mechanical Differences
The Flutter produces oscillating pressure waves while standard PEP devices produce steady pressure. Research demonstrates that the Flutter generates:
- Oscillation frequencies that correlate with expiratory pressure (r = 0.81-0.97) 1
- Pressure variations dependent on device angle (optimal at +40° to 0°, reduced at -40°) 1
- Flow-dependent pressure generation (r > 0.93 correlation) 1
Clinical Performance Comparison
Flutter vs Standard PEP
In a head-to-head trial over one year in CF patients, standard PEP masks outperformed the Flutter device 2:
- Flutter group: FVC declined -8.62% vs PEP +0.06% (p=0.05)
- Flutter group: 18 hospitalizations vs PEP 5 hospitalizations (p=0.03)
- Flutter group: increased antibiotic use and costs
Flutter vs Other OPEP Devices
The Flutter performs similarly to other gravity-dependent OPEP devices (Gelomuc, Pari O-PEP) but differs from gravity-independent devices like Acapella and Aerobika 3, 4. The Acapella uses a counterweighted plug and magnet system rather than a ball-in-cone design 3.
Guideline Perspective
The British Thoracic Society guideline treats these as distinct options within airway clearance techniques 5:
- Standard PEP is listed separately from oscillating devices
- Oscillating PEP (Flutter) is specifically named as an alternative technique
- Both are considered when other techniques are ineffective or unacceptable
The guideline evidence shows oscillating PEP (Acapella) improves outcomes, but does not demonstrate Flutter superiority over standard PEP 5.
Clinical Bottom Line
Choose standard PEP masks over Flutter devices when both are options, given the superior long-term outcomes in the comparative trial 2. Reserve Flutter or other OPEP devices for patients who:
- Cannot tolerate standard PEP
- Prefer the oscillatory sensation
- Need gravity-dependent positioning for specific bronchopulmonary segments
- Have failed standard PEP therapy
The Flutter is an OPEP device, which is a type of PEP device, but "PEP device" without qualification typically refers to non-oscillating positive pressure devices.