FLUTTER
®
Mucus Clearance Device
Instructions for Use
PRODUCT DESCRIPTION
The FLUTTER
®
mucus clearance device is shaped like a pipe with a hardened plastic mouthpiece
at one end, a plastic protective, perforated cover at the other end, and a high-density stainless
steel ball resting in a plastic circular cone on the inside (Figures 1 and 2).
INDICATIONS
The FLUTTER
®
provides positive expiratory pressure (PEP) therapy for patients with mucus-
producing respiratory conditions, including: Atelectasis, Bronchitis, Bronchiectasis, Cystic
Fibrosis, Chronic Obstructive Pulmonary Disease (COPD), Asthma or other conditions producing
retained secretions.
CONTRAINDICATIONS
The FLUTTER
®
is contraindicated for patients known to have pneumothorax or overt right-sided
heart failure.
PRINCIPLES OF OPERATION
The principle of the FLUTTER
®
as a mucus clearance device is based on its ability to: (1) vibrate
the airways (which loosens mucus from the airway walls); (2) intermittently increase
endobronchial pressure (which helps maintain the patency of the airways during exhalation so
that mucus does not become trapped as it moves up the airways); and (3) accelerate expiratory
airflow (which facilitates the upward movement of mucus through the airways so that it can be
more easily cleared).
The FLUTTER
®
effect occurs during the expiratory phase of respiration. Before exhalation, the
steel ball blocks the conical canal of the FLUTTER
®
. During exhalation, the actual position of the
steel ball is the result of an equilibrium between the pressure of the exhaled air, the force of
gravity on the ball, and the angle of the cone where the contact with the ball occurs. As the steel
ball rolls and bounces up and down, it creates an opening and closing cycle which repeats itself
many times throughout each exhalation (Figure 3). The net result is that oscillations in expiratory
pressure and airflow are produced. When the oscillation frequency approximates the resonance
frequency of the pulmonary system, endobronchial pressure oscillations are amplified and result
in vibrations of the airways. The vibrations produced by these oscillations cause the "fluttering"
sensation from which the FLUTTER
®
derived its name. These vibrations loosen mucus from the
airway walls. The intermittent increases in endobronchial pressure decrease the collapsibility of
the airways during exhalation, increasing the likelihood of clearing mucus from the
tracheobronchial tract. The airflow accelerations increase the velocity of the air being exhaled,
facilitating the movement of mucus up the airways (Figure 4).
The FLUTTER
®
produces a range of oscillation frequencies between 6 and 20 Hz, which
corresponds to the range of the pulmonary resonance frequencies in humans. Attaining oscillation
frequencies in this range is fundamental to the efficacy of the FLUTTER
®
. The individual
pulmonary resonance frequency of each patient is dependent on many factors, including lung
volume, lung elasticity, and degree of airway obstruction. The frequency of oscillation that
produces the best transmission of vibrations in a given patient corresponds to the pulmonary
resonance frequency for that patient. When the resonance frequency of the pulmonary system is
achieved, the pressure variations are amplified, maximizing the vibrations of the airway wall.
These vibrations, coupled with increases in expiratory pressure and airflow, facilitate the
clearance of mucus.
The oscillation frequency produced by the FLUTTER
®
when its stem is in the horizontal position is
approximately 15 Hz. This frequency can be modulated by changing the inclination of the
FLUTTER
®
slightly up (higher frequency) or down (lower frequency) from its original horizontal
position. Adjusting the FLUTTER
®
to the resonance frequency is easily accomplished by the
patient who selects the angle tilt that results in the best transmission of vibrations to his/her
airways.
