2006 OPEN FORUM Abstracts
PERFORMANCE CHARACTERISTICS OF THREE HANDHELD AIRWAY CLEARANCE DEVICES: QUAKE, ACAPELLA AND FLUTTER
Carl Okeson, Ph.D., Kendall
Loomis, B.S., Paul McGowen, RRT Thayer Medical Corporation,
Tucson
,
Arizona
,
USA
Background: Airway clearance methods such as CPT and The Vest (Hill-Rom,
St. Paul
,
MN
) loosen mucus by providing
strong vibration pulses to the airways during both exhalation and inhalation,
and allow a wide range of vibration frequencies (i.e. number of vibratory
pulses per second). Three handheld airway clearance devices are now available
as a supplement to or replacement for CPT or the Vest. When breathed through,
the three handheld devices tested here, the Quake® (Thayer Medical,
Tucson
,
AZ
), the Acapella® (green) (DHD Healthcare,
Wampsville
,
NY
), and the Flutter®
(Axcan Scandipharm,
Birmingham
,
AL
), generate
pressure waves in the airways of the patient to loosen mucus. In this study, the
three handheld devices were compared according
to three key performance criteria: pressure wave frequency (i.e. how many
pressure pulses are delivered to the lungs per second), mean pressure wave
amplitude (i.e. the average strength of the pressure pulses) during exhalation,
and mean pressure wave amplitude during inhalation.
Method: Three of
each device (n=3) were evaluated at three different settings (handle turning at
30, 60 and 120 RPM for the Quake; counterclockwise,
midpoint, and clockwise dial settings for the Acapella;
0° (horizontal), 20° and 40° alignments for the Flutter). The devices were
attached via 22 mm respirator tubing to a modified Harvard Breathing Apparatus
(Holliston, MA) simulating tidal breathing of 1500 mL
and 1000 mL at 12 breaths/minute and 1:1 I:E. Tidal
volumes of 1500 mL and 1000 mL
were used to mimic the deeper breathing, per manufacturer's instructions,
performed by patients when using handheld devices. Resulting pressure waves were
measured with Honeywell (
Morris
Township
, NJ) ASDX series voltage
pressure sensors attached to the mouthpieces of the handheld devices. The
output of the pressure sensors was collected on a PC and analysed in Excel.
Device performances were compared via two-tailed T-tests; p ≤ 0.05
indicated a significant difference.
Results: The results are summarized
in the table. The Quake had a wider frequency range than the Acapella and Flutter at the settings evaluated. The best
mean amplitudes for the Quake during exhalation (observed at the 30 RPM setting)
were significantly higher than the best of the Acapella
(at the midpoint setting) and the Flutter (at 0°) at both the 1500 mL and 1000 mL tidal volumes. The
Quake was the only device that provided vibratory pulses during inhalation.
Conclusion: Under the conditions evaluated, the Quake offered both greater flexibility in
pressure wave frequency and stronger pressure pulses than both the Acapella and Flutter during the entire breathing cycle.
These stronger pressure pulses likely translate into greater vibration of
patients' airways. By providing strong
vibratory pulses during both exhalation and inhalation with a wider range of
vibration frequencies, the Quake best mimics the performance of CPT or The
Vest.
| Performance Characteristics (SDs in Parentheses) | Quake | Acapella | Flutter |
| Frequency Range : Min - Max (Pulses/Second) | 6.1 - 23.5 | 12.5 - 25.5 | 12.1 - 16.8 |
| 1500 mL Tidal Volume: | |||
| Best Mean Pulse Amplitude - Exhalation (cm H2O) | 14.1 (1.2)* | 7.4 (0.7) | 8.4 (0.3) |
| Best Mean Pulse Amplitude - Inhalation (cm H2O) | 9.3 (1.9)* | 0 | 0 |
| 1000 mL Tidal Volume: | |||
| Best Mean Pulse Amplitude - Exhalation (cm H2O) | 7.8 (0.7)* | 4.3 (0.2) | 6.5 (0.3) |
| Best Mean Pulse Amplitude - Inhalation (cm H2O) | 5.8 (0.9)* | 0 | 0 |
| *Significantly higher than other devices; p < 0.05 |