Assisted Cough and Pulmonary Compliance in Patients with Duchenne Muscular Dystrophy

Abstract

The aim of this study was to investigate the factors affecting cough ability, and to compare the assisted cough methods in patients with Duchenne muscular dystrophy (DMD). A total seventy-one male patients with DMD were included in the study. The vital capacity (VC) and maximum insufflation capacity (MIC) were measured. The unassisted peak cough flow (UPCF) and three different techniques of assisted peak cough flow were evaluated. UPCF measurements were possible for all 71 subjects. But when performing the three different assisted cough techniques, peak cough flows (PCFs) could be obtained from only 51 subjects. The mean value of MICs (1801 ± 780 cc) was higher than that of VCs (1502 ± 765 cc) (p < 0.01). All three assisted cough methods showed a significantly higher value than the unassisted method (F=80.92, p < 0.01). The manual assisted PCF under MIC (MPCFmic) significantly exceeded those produced by manual assisted PCF (MPCF) or PCF under MIC (PCFmic). The positive correlation between the MIC, VC difference (MIC-VC), and the difference between PCFmic and UPCF (PCFmic-UPCF) was seen (r=0.572, p < 0.01). The preservation of pulmonary compliance is important for the development of an effective cough as well as assisting the compression and expulsive phases. Thus, the clinical importance of the inspiratory phase and pulmonary compliance in assisting a cough should be emphasized.

Cough Augmentation in Subjects With Duchenne Muscular Dystrophy: Comparison of Air Stacking via a Resuscitator Bag Versus Mechanical Ventilation

“…Future studies will be required to confirm this hypothesis. The magnitude of improvement in cough peak flow with air stacking varies in the literature between 19 and 87%, 15,22 possibly due to different populations, baseline lung function, the specific air stacking technique used, and the expertise of the therapist. FVC, P Emax , and inspiratory capacity are correlated with unassisted cough peak flow value, 23 with those subjects with poorer lung function recording smaller cough peak flow values but benefitting most from cough augmentation techniques.…”

“…In this study, we found that air stacking-assisted cough peak flow produced similar values compared with participants' manually assisted cough peak flow, a finding that supports previous work in this area. 10,22,23 Although we did not combine manually assisted coughing with air stacking in this study, prior data would suggest that combining these techniques to augment the different components of a cough has an even greater benefit on cough peak flow. 10,22,23,28 However, the question of how to best achieve air stacking, either as a stand-alone technique or in combination, has not previously been addressed.…”

“…10,22,23 Although we did not combine manually assisted coughing with air stacking in this study, prior data would suggest that combining these techniques to augment the different components of a cough has an even greater benefit on cough peak flow. 10,22,23,28 However, the question of how to best achieve air stacking, either as a stand-alone technique or in combination, has not previously been addressed. Given the high cost of ventilators, positive pressure devices, and mechanical in-exsufflation machines, there is a need for a clinically comparable but cheaper alternative for cough augmentation.…”

Neuromuscular Diseases and Rehabilitation

“…The assisted coughing device produces an airflow of approximately 10 L/s with pressures between -40 cm HO 2 and 40 cm HO 2 . It is a very vital and efficient device to use in patients using a mechanical ventilator and has reduced coughing ability [190]. Noninvasive mechanical ventilation devices are employed in later stages of NMDs.…”

Use of air stacking and abdominal compression for cough assistance in people with complete tetraplegia

“…10 The assessment of cough effectiveness can be performed through PCF using a pneumotachometer or a portable flowmeter (generally used for measurements of peak expiratory flow by using, commonly, a mouthpiece). 11 Expiratory flow values equal or below 160 l min À1 are considered as ineffective for removing airway secretions. 10 Meanwhile, values equal or below 270 l min À1 generate an increased risk of developing respiratory complications, which has been demonstrated in patients with Duchenne Muscular Dystrophy (DMD).…”