The Science Journal of the American Association for Respiratory Care

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

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