Flutter Valve and Acapella (PEP Therapy) Vector

Flutter Valve vs. Acapella: PEP Therapy Devices (2024)

by | Updated: May 7, 2024

Positive expiratory pressure (PEP) therapy is a vital technique for clearing mucus from the lungs, playing a crucial role in managing conditions like cystic fibrosis.

This therapy has two main forms: flutter valves and acapella devices, both of which facilitate the removal of lung secretions.

This article explores the mechanisms and effectiveness of PEP therapy, highlighting how flutter valves and acapella devices function, their recommended uses, potential contraindications, and possible risks.

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What is PEP Therapy?

PEP therapy is a therapeutic technique for mobilizing lung secretions, minimizing air trapping, and preventing lung collapse. It involves the patient exhaling actively into a device that creates back-pressure.

This pressure not only helps to expand the lungs but also moves the secretions into larger airways, where they can be expelled by coughing or suctioning.

The primary devices used in PEP therapy are flutter valves and acapella devices. Each works slightly differently to achieve the same goal of secretion clearance.

What is a Flutter Valve?

A flutter valve is a prevalent type of oscillatory PEP therapy device that is especially beneficial for patients with cystic fibrosis. This compact, handheld device contains a triangular chamber with a freely moving steel ball inside.

During use, the patient exhales into the device against a resistance, causing the ball to vibrate rapidly.

These vibrations generate high-frequency oscillations that help to dislodge and break down mucus, making it easier to clear from the lungs.

Parts of a Flutter Valve Device Labeled Vector Illustration


A flutter valve is made up of the following parts:

  • Removable mouthpiece
  • Body
  • Steel ball
  • Expiratory resistance dial
  • One-way valve
  • 22 mm O.D. connection

The user exhales into the mouthpiece, which is connected to the body, causing the steel ball to rattle, creating high-frequency oscillations.

The expiratory resistance dial can be adjusted to increase or decrease the level of back-pressure. The one-way valve prevents air from entering the device during inhalation.

What is an Acapella Device?

An acapella device is a compact, handheld instrument that uses positive expiratory pressure (PEP) therapy to aid in the clearance of mucus from the lungs.

While it shares many applications and indications with the flutter valve, it operates on a distinct mechanism to generate backpressure and oscillations, enhancing its effectiveness in mucus clearance.

Types of Acapella Breathing Devices Green Blue Model Vector


Acapella devices are available in two models, catering to different levels of patient expiratory flow capability:

  • Green Model: This version is suited for patients who can achieve an expiratory flow rate greater than 15 L/min. It requires more effort to operate, making it ideal for those with stronger respiratory capabilities.
  • Blue Model: Designed for ease of use, this model is appropriate for patients with an expiratory flow rate of less than 15 L/min. It is less demanding, making it accessible for individuals with lower respiratory strength.

One significant benefit of the acapella device over the flutter valve is its versatility in use across different patient positions. It can be effectively used whether the patient is sitting, standing, or lying down, providing greater flexibility and comfort during therapy sessions.

In contrast, the flutter valve is typically recommended for use only when the patient is in an upright position, limiting its usability in certain clinical scenarios.


The primary indications for PEP therapy include:

  • To help clear mucus
  • To prevent or reverse atelectasis
  • To reduce air trapping
  • To help mobilize retained secretions
  • To maximize the delivery of aerosolized medications


While there are no absolute contraindications for PEP therapy, several relative contraindications warrant careful consideration before implementing this treatment.

These include:

  • Untreated pneumothorax
  • Intracranial pressure >20 mmHg
  • Hemodynamic instability
  • Active hemoptysis
  • Recent facial trauma or surgery
  • Patients with acute asthma or COPD
  • Acute sinusitis
  • Acute epistaxis
  • Tympanic membrane rupture
  • Acute nausea

PEP therapy is typically not recommended for children under three years old, as they may not have the capacity to comprehend and follow the necessary instructions for using the device effectively.

Additionally, adult users must be capable of taking a deep breath and generating an expiratory pressure of more than 10 to 12 mL/kg. This level of pressure is essential to produce the oscillations required for effective PEP therapy.

Note: Ensuring that patients can meet this requirement is crucial for the successful application of the therapy.

Hazards of PEP Therapy

Using a flutter valve or acapella device is generally regarded as safe for airway clearance therapy. Nonetheless, there are some potential hazards associated with their use that warrant consideration.

These include:

  • Pulmonary barotrauma
  • Increased work of breathing
  • Increased intracranial pressure (ICP)
  • Air swallowing
  • Myocardial ischemia
  • Decreased venous return to the heart

How to Use a Flutter Valve or Acapella Device

Follow these steps to effectively use a flutter valve or acapella device for airway clearance:

  • Assemble the Device: Ensure that all parts are securely fitted together according to the manufacturer’s instructions.
  • Position Yourself Correctly: For the flutter valve, remain upright to ensure proper function. The acapella device can be used in any position, offering greater flexibility.
  • Take a Deep Breath: Fill your lungs completely to maximize the effectiveness of the exhalation.
  • Create a Seal: Place the mouthpiece in your mouth and seal your lips tightly around it to prevent air from escaping.
  • Exhale with Backpressure: Exhale slightly faster than normal against the resistance created by the device. This helps generate the necessary oscillations for mucus clearance.
  • Adjust for Maximum Vibration: Fine-tune the device’s settings until you feel strong vibrations in your chest, indicating effective mucus mobilization.
  • Perform Multiple Exhalations: Repeat the exhalation process up to 10 times per session, maintaining the rhythm and pressure.
  • Finish with Forceful Exhalations: Conclude the session with one or two maximal expiratory efforts: inhale deeply and then exhale forcefully through the device.
  • Cough to Clear Secretions: After using the device, perform a strong cough to expel the loosened mucus.
  • Repeat the Process: Complete four to eight cycles of the above steps during each therapy session to ensure thorough clearance of secretions.

Diseases That Benefit From PEP Therapy

PEP therapy is beneficial for managing a variety of respiratory conditions that involve secretion accumulation in the airways.

Some examples include:

  • Cystic Fibrosis: This genetic disorder leads to the production of thick, sticky mucus that can obstruct the airways. PEP therapy helps mobilize and clear this mucus, thereby reducing the risk of infections and improving lung function.
  • Chronic Obstructive Pulmonary Disease (COPD): In conditions such as chronic bronchitis and emphysema, mucus clearance is a major challenge. PEP therapy can aid in clearing mucus, which may improve breathing and reduce the frequency of exacerbations.
  • Asthma: Although primarily an inflammatory disorder, asthma can also involve mucus hypersecretion. PEP therapy can be used as part of an asthma management plan to help clear mucus and improve ventilation.
  • Bronchiectasis: This condition involves permanent enlargement of parts of the airways, leading to significant mucus build-up. PEP therapy is useful in clearing mucus and preventing further complications like bacterial infections.
  • Atelectasis: This condition is characterized by the partial collapse of a lung or a segment of a lung. PEP therapy can help re-expand the affected areas by increasing air pressure and aiding in mucus clearance, which is often a contributing factor to the collapse.
  • Neuromuscular Diseases: In diseases such as muscular dystrophy, where the respiratory muscles may be weakened, PEP therapy can assist in clearing mucus, thus reducing the workload on weakened muscles and helping maintain lung function.

Note: PEP therapy’s ability to assist in mucus clearance makes it a valuable adjunct treatment in the respiratory care of patients with these conditions, contributing to better respiratory health and improved quality of life.

Delivering Aerosol Drugs with PEP Therapy

Combining aerosol drug therapy with PEP therapy can enhance the treatment’s effectiveness. This is typically achieved by integrating an in-line handheld nebulizer or a metered-dose inhaler with the device, attaching it directly to the one-way inlet valve.

This setup improves the distribution of medication within the peripheral airways, making the treatment more efficient in managing respiratory conditions.

FAQs About Flutter Valves and PEP Therapy

What Does a Flutter Valve Do?

A flutter valve is a type of respiratory therapy device used primarily for airway clearance. It helps loosen and mobilize mucus from the lungs by creating oscillations and back pressure when a person exhales through it.

This mechanism facilitates easier breathing by improving mucus clearance.

How Does a Flutter Valve Help Your Lungs?

A flutter valve aids lung function by generating vibrations and pressure during exhalation. This helps break up and thin out mucus, making it easier to expel through coughing.

Regular use can enhance lung capacity, reduce the risk of infections, and improve overall respiratory health, especially for individuals with conditions that cause mucus buildup.

What is the Best Device for Removing Mucus from the Lungs?

The best device for removing mucus depends on the user’s specific health needs and comfort with the device. Both flutter valves and acapella devices are highly effective.

Flutter valves are excellent for producing high-frequency oscillations that help break down mucus, while acapella devices offer adjustable resistance and can be used in any position, making them versatile.

Consulting with a healthcare provider can help determine the most suitable option based on individual conditions and preferences.

What is Another Name for a Flutter Valve?

A flutter valve and acapella are sometimes used interchangeably; however, it’s important to note that they are actually different devices.

While both are used for airway clearance, they employ distinct mechanisms to achieve this.

What is Vibratory PEP Therapy?

Vibratory PEP therapy uses high-frequency vibrations or oscillations to shift small air volumes back and forth within the respiratory tract. This movement helps to loosen mucus, facilitating its removal through coughing.

Key devices used in vibratory PEP therapy include flutter valves and acapella breathing devices, with lesser-known options like the RC-Cornet, Lung Flute, Quake, and Aerobika also available.

How Often Should You Perform PEP Therapy?

The frequency with which PEP therapy should be performed varies based on individual patient needs.

Typically, two to four sessions per day are recommended, although this can be adjusted according to the severity of their condition and the guidance of a healthcare professional.

What are the Advantages of PEP Therapy?

PEP therapy offers several benefits, making it a valuable option for airway clearance therapy. It is as effective as other techniques like autogenic drainage but has the added benefits of being portable and easy to use.

Additionally, PEP therapy can be self-administered, making it a convenient and cost-effective option for ongoing respiratory management.

What is the Difference Between an Acapella and a Flutter Valve?

The main difference between an acapella and a flutter valve lies in their design and the mechanism by which they help clear mucus from the lungs.

A flutter valve typically uses a steel ball that moves within a cone-shaped device to create vibrations when the user exhales. This action helps break up mucus.

In contrast, an acapella device uses a counterweighted plug and magnet to create adjustable resistance and vibrations during exhalation, which can be used in any body position, offering greater flexibility than the flutter valve.

What Does a Flutter Valve Look Like?

A flutter valve is a small, handheld device, often triangular or cone-shaped. It typically consists of a plastic body with a mouthpiece at one end and an opening at the other that houses a freely moving steel ball.

The design is simple yet effective for its purpose of creating oscillatory pressure to help clear mucus from the lungs.

Can a Flutter Valve Help with COPD?

Yes, a flutter valve can be beneficial for patients with chronic obstructive pulmonary disease (COPD). By facilitating the clearance of mucus, it can help reduce the frequency of exacerbations and improve overall lung function.

Regular use of a flutter valve as part of a comprehensive COPD management plan can enhance breathing efficiency and help maintain clearer airways.

Where to Buy an Acapella or Flutter Valve Device?

Acapella and flutter valve devices can be purchased at medical supply stores, both in physical locations and online.

They are also available through various online retailers such as Amazon.

It’s important to ensure that any device purchased is from a reputable supplier and to consult with a healthcare provider before starting use to ensure it is appropriate for your specific health needs.

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Final Thoughts

PEP therapy, including flutter valves and acapella devices, serves as a vital tool in respiratory care, especially for those managing conditions that involve mucus accumulation.

With options to accommodate different respiratory capacities and the ability to use these devices in various positions, PEP therapy provides a flexible, efficient, and user-friendly approach to managing respiratory health.

Regular and correct use of these devices, as advised by healthcare professionals, can significantly improve the quality of life for those with chronic respiratory conditions.

John Landry, BS, RRT

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.


  • Figueiredo PH, Zin WA, Guimarães FS. Flutter valve improves respiratory mechanics and sputum production in patients with bronchiectasis. Physiother Res Int. 2012.
  • Rocamora-Pérez P, Benzo-Iglesias MJ, Valverde-Martínez MLÁ, García-Luengo AV, Aguilar-Parra JM, Trigueros R, López-Liria R. Effectiveness of positive expiratory pressure on patients over 16 years of age with cystic fibrosis: systematic review and meta-analysis. Ther Adv Respir Dis. 2022.

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