2004 OPEN FORUM Abstracts
ACAPELLA PERFORMANCE MEASUREMENT IN A VENTILATOR CIRCUIT
Mary Ann Couture,
BS. RRT, Hartford Hospital, Hartford, CT.
Introduction: Acapella
(DHD Healthcare, Wampsville, NY) is a device that patients
self-administer to facilitate removal of pulmonary secretions, and
improve ventilation of the lungs through re-expansion of lung tissue.
These devices are inexpensive and readily available, although their
use is limited to patients who can cooperate with deep breathing and
cough. The PEP and oscillatory vibrations that the device generates
does not carry some of the risks or limitations of manual chest
physiotherapy. Without the mouthpiece, the Acapella has a
standardized 15 mm ID adapter that can be re-fitted with a 22 mm ID
adapter to fit into the exhalation port of either an open-end
ventilator circuit or a resuscitation bag. The purpose of this bench
study is to determine the different positive expiratory pressure
levels at various settings and determine if the choice of ventilator:
Crossvent portable ventilator (Bio-Med Devices Inc., Guilford, CT),
can safely deliver breaths with Acapella attached to the expiratory
port.
Methods: A
double test lung (Siemens 190) is attached to the Crossvent with the
following settings: IMV8, VT 1.0 L, flowrate 50 L/min, PEEP 0 and
pressure sensitivity of –2 cm H2O. The Acapella is
attached to the exhalation port. A NICO monitor (Respironics,
Wallingford, CT) with computer software measures multiple data points
for each breath in real time. The sensor is placed between the
ventilator wye and the test lung. Any change in expiratory time
indicates auto triggering of breaths. Each of Acapella’s 5
settings come with no label. Settings for data collection of both the
green and blue devices is on a scale numbered I-V. Setting # I
(full counterclockwise or full negative) is labeled as the setting
with the lowest frequency/resistance according to the package
directions and # V (full clockwise or full positive) as the setting
with greatest resistance. Three samples of each color with different
lot numbers were tested. Acapella measurements are compared to a
control test with no device in line.
Results: Acapella
directions indicate that setting # I has the lowest resistance. This
is true in the green device but the opposite occurs in the blue
device. Auto-PEEP increases from setting I to V in both devices, but
PEEP is not found in all settings. High RAW readings
adversely effect VTE. While data from each device has a
low standard deviation, there is wide variation in expiratory data
between the individual devices, especially in the blue device that
can produce high RAW levels and greatly reduce VTE.
Auto-triggering of breaths was not detected in this study.
| Control | 6.8 ± 0.3 (6-7) | 940 ± 30.5 (895-965) | 0 |
| Green I | 8.6 ± 1.0 (7-11) | 816 ± 14.8 (778-843) | 0 |
| II | 8.0 ± 1.9 (6-11) | 785 ± 26.3 (753-834) | 0.2 ± 0.3 (0-1) |
| III | 8.4 ± 2.0 (6-12) | 743 ± 22.4 (712-809) | 0.8 ± 0.6 (0-1) |
| IV | 8.5 ± 2.1 (6-12) | 730 ± 61.1 (652-832) | 1.8 ± 0.8 (1-3) |
| V | 10.1± 6.1 (5-19) | 715 ± 195.4 (377-910) | 7.8 ± 2.8 (4-11) |
| Blue I | 32.5 ± 32.9 (5-84) | 515 ± 257.0 (163-826) | 2.9 ± 4.2 (0-8) |
| II | 31.5 ± 21.3 (9-69) | 457 ± 234.2 (148-790) | 0.9 ± 0.7 (0-2) |
| III | 46.3 ± 34.7 (8-99) | 450 ± 264.5 (104-721) | 2.1 ± 0.5 (1-3) |
| IV | 29.0 ± 20.3 (8-62) | 453 ± 242.9 (171-768) | 5.2 ± 0.6 (4-6) |
| V | 11.7 ± 5.0 (5-21) | 532 ± 108.0 (383-686) | 10.1± 1.5 (8-12) |
Conclusion: The
properties of the green Acapella may benefit patients who receive
mechanical ventilation with careful observation of PEEP levels. The
high auto-PEEP findings on green and blue setting #V may be useful
for patients requiring high ventilator PEEP settings. Further
investigation is needed. The blue device, with high RAW readouts, may
be too difficult for patients to exhale adequate volumes.
Acknowledgment:
NICO measurement software was used with permission from Respironics
of Wallingford, CT