A Comparison of Cough Assistance Techniques in Patients with Respiratory Muscle Weakness.
OBJECTIVE
To assess the ability of a mechanical in-exsufflator (MI-E), either alone or in combination with manual thrust, to augment cough in patients with neuromuscular disease (NMD) and respiratory muscle dysfunction.


METHODS
For this randomized crossover single-center controlled trial, patients with noninvasive ventilator-dependent NMD were recruited. The primary outcome was peak cough flow (PCF), which was measured in each patient after a cough that was unassisted, manually assisted following a maximum insufflation capacity (MIC) maneuver, assisted by MI-E, or assisted by manual thrust plus MI-E. The cough augmentation techniques were provided in random order. PCF was measured using a new device, the Cough Aid.


RESULTS
All 40 enrolled participants (37 males, three females; average age, 20.9±7.2 years) completed the study. The mean (standard deviation) PCFs in the unassisted, manually assisted following an MIC maneuver, MI-E-assisted, and manual thrust plus MI-E-assisted conditions were 95.7 (40.5), 155.9 (53.1), 177.2 (33.9), and 202.4 (46.6) L/min, respectively. All three interventions significantly improved PCF. However, manual assistance following an MIC maneuver was significantly less effective than MI-E alone. Manual thrust plus MI-E was significantly more effective than both of these interventions.


CONCLUSIONS
In patients with NMD and respiratory muscle dysfunction, MI-E alone was more effective than manual assistance following an MIC maneuver. However, MI-E used in conjunction with manual thrust improved PCF even further.
Department of Rehabilitation Medicine, Incheon Workers' Compensation Hospital, Incheon, Korea.|Department of Medicine, The Graduate School of Yonsei University, Seoul, Korea.
Sun Mi
SM
Kim
Department of Rehabilitation Medicine, Gangnam Severance Hospital, Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, Korea.
Won Ah
WA
Choi
Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Korea.
Yu Hui
YH
Won
Department of Rehabilitation Medicine, Gangnam Severance Hospital, Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, Korea. kswoong@yuhs.ac.
Seong Woong
SW
Kang
D000293:Adolescent; D000328:Adult; D000368:Aged; D003371:Cough; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007327:Insufflation / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009468:Neuromuscular Diseases / Q000503:physiopathology*; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D011312:Pressure; D012129:Respiratory Function Tests / Q000295:instrumentation / Q000379:methods; D012132:Respiratory Muscles / Q000503:physiopathology*; D012138:Respiratory Therapy / Q000379:methods*; D016896:Treatment Outcome; D014797:Vital Capacity / Q000502:physiology
Neuromuscular disease; cough augmentation; mechanical in-exsufflator; peak cough flow