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

Abstract

BACKGROUND: Air stacking improves cough effectiveness in people with Duchenne muscular dystrophy (DMD) and respiratory muscle weakness. However, it is not known whether air stacking is more effective via a resuscitator bag or a home ventilator. METHODS: This prospective randomized study investigated the effect of air stacking via a volume-cycled home ventilator versus via a resuscitator bag in participants with DMD. Maximum insufflation capacity and peak expiratory flow during spontaneous (cough peak flow) and air stacking-assisted cough maneuvers (air stacking-assisted cough peak flow) were measured. RESULTS: Fifty-two adult DMD subjects receiving noninvasive ventilation were included in the study: 27 participants performed air stacking via their home ventilator (home-ventilator group; age ‫؍‬ 25.3 ؎ 5.1 y; forced vital capacity (FVC) ‫؍‬ 809 ؎ 555 mL), and 25 participants used a resuscitator bag (resuscitator-bag group; age ‫؍‬ 24.7 ؎ 5.7 y, FVC ‫؍‬ 807 ؎ 495 mL). Following a single training session, air stacking could be performed successfully by 89% (home ventilator) and 88% (resuscitator bag) of participants. There were comparable maximum insufflation capacities (1,481 mL for the home-ventilator group vs 1,344 mL for the resuscitator-bag group, P ‫؍‬ .33) and mean air stacking-assisted cough peak flow values (199 L/min for the home-ventilator group vs 186 L/min for the resuscitator-bag group, P ‫؍‬ .33) between techniques. Air stacking-assisted cough peak flow increased significantly compared with baseline in both groups (mean increase: ؉51% [home ventilator] vs ؉49% [resuscitator bag], P < .001), with individual air stacking-assisted cough peak flow improvements ranging from ؊20 to 245%. CONCLUSIONS: Cough augmentation is an important component of the respiratory management of people with a neuromuscular disorder. No difference in cough effectiveness as measured by air stacking-assisted cough peak flow was found in air stacking via a ventilator compared with via a resuscitator bag. Both methods achieved mean air stacking-assisted cough peak flow values of >160 L/min. Provision of an inexpensive resuscitator bag can effectively improve cough capacity, and it is simple to use, which may improve access to respiratory care in people with DMD.

Respiratory Implications of Pediatric Neuromuscular Disease

“…Among 52 adults with DMD, manual insufflation was equivalent to use of a mechanical ventilator in increasing cough peak flow over unassisted cough peak flow values. 41 There are, however, limits to the effectiveness of manually assisted cough and manually assisted cough with breath-stacking. Chest-wall distortion and scoliosis can reduce the usefulness of manually assisted cough, and the frequency at which manually assisted cough is required during acute illnesses can cause caregiver fatigue.…”

Assessment of gas compression and lung volume during air stacking maneuver

“…Air stacking, obtained by either a positive pressure mechanical ventilator or by a manual insufflator (Toussaint et al 2016), is currently being considered, particularly in patients with restrictive disorders, to increase maximal lung volume and consequently peak cough flow (Jeong and Yoo Table 2 Gas compression and pressure in a single air stacking maneuver…”

Respiratory adjuncts to NIV in neuromuscular disease

“…Breath‐stacking can also be performed using GPB or a volume‐cycled NIV device. The ‘NIV method’ appears to be as effective as a manual resuscitation bag in increasing MIC, assisted PCF and mastering the technique …”