Bubble-PEP May Help Clear Airways in Patients with Bronchiectasis

Bronchiectasis News covers a potentially beneficial treatment for patients with bronchiectasis: bubble-positive expiratory pressure, or Bubble-PEP. These devices help clear mucus from the lungs. Although other forms of airway clearance techniques have been proven effective, no former studies tested the efficacy of therapist-developed bubble-PEP devices. Find the full study results in Physiotherapy Research International.


Bronchiectasis is a damaging respiratory condition which causes someone’s bronchial tubes to permanently thicken or widen. The bronchial tubes scar. As this occurs, mucus and other bacteria accumulate in the lungs, but the scarring makes it difficult to clear. As a result, patients with bronchiectasis experience infection and inflammation, leading to further damage.

Bronchiectasis is divided into cystic fibrosis (CF) bronchiectasis and non-CF bronchiectasis. Symptoms include a chronic daily cough which produces blood or green/yellow mucus, shortness of breath, chest pain, unintended weight loss, fatigue, and fever. Because of its similar presentation to other conditions, bronchiectasis is estimated to be heavily under-diagnosed.

Read more about bronchiectasis.

The Study


Bubble positive expiratory pressure (bubble-PEP) is an airway clearance technique used to help patients clear buildups in their airways.

Airway clearance techniques assist in loosening and clearing mucus from the lungs. These techniques contribute to increased lung function and higher quality of life.

In this case, positive expiratory pressure (PEP) forces patients to breathe against some sort of resistance. So, in bubble-PEP specifically, patients use a device to blow bubbles in water. According to the West Suffolk NHS Foundation Trust, bubble-PEP works by creating positive pressure.

As a result:

This positive pressure helps to hold open your airways, allowing more air to flow in and out. The air can then get behind the phlegm helping to move it more easily upwards through the open airways.

Bronchiectasis Research Considerations

Active Cycle of Breathing Technique (ACBT) is a common airway clearance technique. The Cystic Fibrosis Foundation notes that this technique is carried out in three parts:

  1. Breath control: breathing in through the nose and out through the mouth helps patients to relax their airways. Patients learning to control their breathing should also relax their chest and shoulders, and hold one hand to their stomach. When breathing out through the mouth, pursed lips increase airway pressure. Repeat 6x.
  2. Chest expansion: Patients should breathe in as deeply as possible, then hold the breath for a few seconds. Next, breathe out gently. Repeat steps 1 and 2 for 2-3x before huffing.
  3. Forced expiration: Also known as huffing, patients take a deep breathe before forcefully exhaling. This helps to dislodge mucus and expel it from the lungs. Patients should continue ACBT until no mucus is brought up during huffing. Learn proper huffing techniques here.

Researchers wanted to understand whether therapist-developed bubble-PEP devices, created from water, a bottle, and a breathing tube, could be as effective in treating bronchiectasis as ACBT.


Researchers compared the efficacy of bubble-PEP to ACBT, as well as to a control group with no therapies. The study followed 35 patients with bronchiectasis who coughed up mucus on a daily basis.

Each patient experienced 3 days of treatment: one for bubble-PEP, one for no intervention, and one for ACBT. Patients were treated for 30 minutes, then sat for one hour. After 30 minutes, patients treated with bubble-PEP and ACBT coughed up similar amounts of mucus. The mucus expelled by the control group was much lower.

However, after 60 minutes, patients treated with bubble-PEP coughed up more mucus than those treated with ACBT. This suggests that while both options are effective in airway clearance, bubble-PEP is most likely to continue clearing mucus following treatment.

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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