Types of Airway Clearance Devices

Cystic fibrosis patients have abnormally thick, stick mucus that is difficult to remove from their airways. In order to prevent infection a combination of medications and airway clearance techniques are used. In the past, the methods of airway clearance we cumbersome, time consuming, and, at times, downright uncomfortable for both patient and care giver. One such example is the "clapping" technique. Sometimes referred to as "beatments" or "thumps" by CF sufferers, the process involved having a caretaker cup his or her hands and physically beat the patient's back in a rhythmic manner. By clapping each section of the lung's lobes, the mucus was dislodged to a point that it could be coughed up and spit out.

Over the last decade many developments have been made in the world of airway clearance devices that make expelling the mucus much easier. Although some patients do still prefer the clapping methods to which they have grown accustomed, newcomers to the disease have many options for airway clearance.

Intrapulmonary Percussive Ventilator (IPV)

This device, available in some hospitals and often called the "Percussion Air" stimulates the airways by directing several bursts of air into the lungs at a predetermined rate. A pneumatic flow interuptor sends a pulsing flow of air at a rate of 100-300 blasts or "cycles" per minute. The device is attached to a special mouthpiece and nebulizer cup so that the patient can benefit from medication simultaneously with the percussion treatment. Due to the high frequencies at which the air pulses, some patients have difficultly tolerating such a method. However, great benefits exist for those who have good posture and have been properly instructed in the technique of using and IPV.

The Flutter(r) Mucous Clearance Device

The Flutter is a small, handheld device that creates positive expiratory pressure (PEP) in order to stimulate the lungs to vibrate or "flutter" enough to dislodge the sticky mucous. The device itself consists of a weighted metal ball resting in a cone that sits atop a diaphragm through which air can flow. When the patient exhales, the cone and ball move around creating the "fluttering" motion that results in PEP. This causes pressure in the airways, keeping them open longer than would happen just through simple tidal breathing. The cap on the end of the device can be twisted to different settings to make the pressure lesser or greater depending on the patient's ability.The range of benefit of the Flutter depends largely on the patient's ability to exhale against the device. Longer, sustained breaths and the use of a technique called "huff coughing" are the best ways to benefit from using the Flutter.

Acapella (tm)

Similar to the Flutter, the Acapella employs the use of positive expiratory pressure. This device is considerably larger than the Flutter, but has a greater range of resistance than can be "dialed in" on one end. One advantage of the Acapella is that the t-piece of a nebulizer can be attached to it, allowing the patient to inhale medication while also engaging in airway clearance. The only drawback is that many home nebulizer-compressor systems do not deliver a high flow rate through the nebulizer cup. This results in wasted medication and decreased benefit for the user. In the hospital setting, however, the air flow can be adjusted to a rate that is high enough to push the medication through the device and reach the mouthpiece, ultimately benefiting the patient. Most often, the Acapella is used independently of nebulizer treatment.

Vests

The most favored and beneficial airway clearance device used by CF patients is the Vest. Different models are available from different companies, and determining which one to use is left to personal preference. The vest works by using a method called high frequency chest compression. The Vest is inflatable, and is connected to a compressor by two air hoses. Once switched on, the vest fills with air, and the air begins to oscillate, thereby loosening the mucus. The frequency (measures in Hertz) and Pressure (psi) can be adjusted according to the needs of the individual. Some patients wear their Vests while exercising, or while inhaling aerosolized medication. The technique of "huff coughing" is also applied while a patient is undergoing a vest treatment. Huff coughing is a type of deep exhalation that enables the airways to stay open longer. It's similar to how a person would breathe if they wanted to see their breath in the cold air, or breathe fog onto a window. When breathing in this way during a vest treatment, it's easier for the patient to cough up the mucous that is being dislodged.

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Additional Resources:

American Thoracic Society List of Airway Clearance Devices (includes Insurance and Cost Information for Acquiring Them)

How To Huff Cough Effectively

Respirtech inCourage vest

The Flutter Valve (From Axcan Pharma)

Hill-Rom Vest

Acapella PEP Therapy

Percussionaire Company