Comparing Flutter Device to IPV
By Charles R. Miller, MS, RRT
Traditionally, chest physical therapy (CPT) has been used in patients with diseases associated with production of copious secretions and atelectasis. However, an extensive review of CPT by Eid et al.1 shows CPT has only a short list of indications and may even be harmful. In some instances, it may not even be all that beneficial either, because extrathoracic assaults to the chest wall do not always allow vibrations to be transmitted to the lung parenchyma where it is needed.
Recently, airway clearance techniques using internal assaults have been introduced to the respiratory care community. Among the devices used for this technique are PEP valve, Flutter valve and Intrapulmonary Percussive Ventilation (IPV). Proponents of each device strongly champion their own method. While some studies have compared traditional, external CPT with some of the new equipment designed to start the process internally, to our knowledge, no study has previously been done to compare patient results using two of the newer devicesthe Flutter valve and IPV therapy.
WITH THAT THOUGHT in mind, Montana clinicians set up a study comparing IPV and the Flutter device to determine the ability of the two devices to cause bilateral basal chest oscillations. Ten patients with either thick inspissated secretions and/or atelectasis were included in the study.
The Flutter valve is a small hand-held, pipe-like device that capitalizes on a patient’s ability to generate relatively high expiratory flows over several seconds. If the patient exhales at a constant high flow, a steel ball in the pipe bowl oscillates and modulates a pressure gradient in the airway. This vibrates the bronchial walls and may help loosen secretions. The degree of chest wiggle and expiratory pressure is highly dependent on patient effort. In effect, the device is an oscillating PEP valve. It costs about $190.
IPV THERAPY uses a device delivering positive percussive inspiratory/expiratory pressure which is not dependent on patient effort. The clinician controls the amount of pressure and pulsatile flow by adjusting frequency and drive pressure. IPV is a combination therapy including components of incentive spirometry, hydration, bronchodilators, oscillatory PEP and positive inspiratory airway pressure. Cost of the device ranges from $1,500 to $3,500.
In our study, the efficacy of the therapy was determined by visible and tactile bilateral chest oscillations. We developed a chest wiggle index (CWI) score to assist therapists in assessing optimal treatment strategies.
Under the scoring system, a CWI of 0 denoted no visible or tactile thorax oscillations; a CWI score of 1 showed upper bilateral thorax oscillations; a CWI score of 2 indicated upper and bibasilar thorax oscillations.
We assumed one of the best clinical indicators for assessing the effectiveness of the two devices would be to evaluate the external thorax oscillations during therapy. Logically, with Flutter or IPV, the oscillations begin from inside the airway lumens and emanate toward the periphery and finally are observed or felt on the external chest wall.
Conversely, traditional CPT begins with oscillations/percussions on the extrathoracic chest wall and caregivers hope vibrations reach the lung periphery.
Our study clearly showed we were able to achieve the maximum CWI score of 2 in nine of the 10 patients with IPV therapy. This means the entire patient thorax was shaking like a bowl of Jello. By contrast, six of the 10 patients achieved a CWI of 0 with the Flutter valve; only one patient was able to score a CWI of 2 with the Flutter valve.
DATA SUGGEST if patients are unable to maintain peak expiratory flows of > 200 L/min for extended times, the Flutter valve is ineffective.
More studies are needed to compare the role of Flutter valve and IPV in the management of thick inspissated secretions. Based on further observations of our research, we found patients with airway clearance problems responded best to IPV when the IPV treatment was given for 20 minutes three to four times a day by either a respiratory therapist or a motivated, well-trained family member or health care assistant.
Table 1 shows a striking difference between IPV and the Flutter valve in CWI scores. Only 40 percent of the patients effectively used the Flutter, while 90 percent appeared to have optimal use of IPV.
Both devices allow patients to perform their own therapy. The Flutter is smaller and easier to carry; however, it does not interface to a mask of 15 mm fitting. It does not provide inspiratory mechanical dilation of the airways or a high-density mist. Therefore, no aerosolized drug therapy is available.
The Flutter is best used in a non-hospital setting in selected patients who do not have artificial airways or need a mask for therapy.
HARDY HAS REPORTED favorable results with the Flutter in an excellent review of airway clearance techniques.2 Unfortunately, the author was unaware of the IPV device and did not include it in the review. Conversely, E. Lyons et al. found the Flutter showed significant decrease in sputum volume when compared to traditional chest physiotherapy.3
It was concluded the Flutter VRP1 cannot be substituted for physiotheraphy and adds little, if anything, to physiotherapy in young adults with cystic fibrosis.
IPV therapy is currently being used successfully in western Montana. No other device can duplicate the combination of dense aerosol, SVN and oscillatory PEP therapy delivered simultaneously in one treatment.
Patients with severe expiratory flow limitations respond best to positive percussive inspiratory and expiratory pressure (IPV) which can promote alveolar recruitment, loosen secretions and create a positive expiratory flow gradient from the periphery of the lung to the proximal airway.
IPV is the treatment of choice since it is independent of patient expiratory flow effort and can be adapted for changing severity of lung dysfunction.
EFFECTIVE AIRWAY clearance management depends on the technical skills of practitioners and their abilities to educate and coach their patient properly.2,4 We urge therapists to experience the vastly different oscillatory/percussive capabilities of the Flutter valve and IPV therapy by using each device on themselves.
Based on our research here, IPV and the Flutter valve are far from equivalent airway clearance techniques, although both devices have been shown to be effective.
The techniques should be available to patients suffering from bronchial hypersecretion. Both are major advances in chest physiotherapy.
* About the author: Charles Miller is the director of clinical education at the University of Montana-Missoula, College of Technology.
1. Eid N, Buchheit J, Neuling M, Phelps H. Chest physiotherapy in review. Respir Care. 1991;36:270-282.
2. Hardy KA. A review of airway clearance: new techniques, indications and recommendations. Respir Care. 1994;39:440-455.
3. Lyons E, Chatham K, Campbell IA, Prescott RJ. Evaluation of the Flutter VRPI device in young adults with cystic fibrosis. Med Sci Res. 1993;21:101-102.
4. Natale JE, Pfeifle J, Hommnick DN. Comparison of intrapulmonary percussive ventilation and chest physiotherapy. Chest. 1994; 105:1789-1793.