Air stacking: effects on pulmonary function in patients with spinal muscular atrophy and in patients with congenital muscular dystrophy,

Abstract

OBJECTIVE: Respiratory complications are the main causes of morbidity and mortality in patients with neuromuscular disease (NMD). The objectives of this study were to determine the effects that routine daily home air-stacking maneuvers have on pulmonary function in patients with spinal muscular atrophy (SMA) and in patients with congenital muscular dystrophy (CMD), as well as to identify associations between spinal deformities and the effects of the maneuvers. METHODS: Eighteen NMD patients (ten with CMD and eight with SMA) were submitted to routine daily air-stacking maneuvers at home with manual resuscitators for four to six months, undergoing pulmonary function tests before and after that period. The pulmonary function tests included measurements of FVC; PEF; maximum insufflation capacity (MIC); and assisted and unassisted peak cough flow (APCF and UPCF, respectively) with insufflations. RESULTS: After the use of home air-stacking maneuvers, there were improvements in the APCF and UPCF. In the patients without scoliosis, there was also a significant increase in FVC. When comparing patients with and without scoliosis, the increases in APCF and UPCF were more pronounced in those without scoliosis. CONCLUSIONS: Routine daily air-stacking maneuvers with a manual resuscitator appear to increase UPCF and APCF in patients with NMD, especially in those without scoliosis.

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

“…11,13,14,26 A recent study reported that air stacking can be learned by children with severe muscle weakness. 27 In 18 subjects affected by spinal muscular atrophy and congenital muscular dystrophy, air stacking was shown to be an effective airway clearance therapy. However, air stacking was more effective in the absence of scoliosis.…”

1st Italian SMA Family Association Consensus Meeting:

“…Only a recent study reported values < 270 L/min of PCF in a mixed group of 4 SMA II and 4 SMA III patients [42] and an improvement of this parameter after air stacking. Based on this report and on clinical observations expiratory aids should be Page 11 of 31 recommended in SMA III patients, particulary during acute illness.…”

Respiratory adjuncts to NIV in neuromuscular disease

“…Small, prospective observational studies of 3–6 months’ duration have reported conflicting outcomes. FVC and MIC did not change in 18 patients, but small gains in PCF (257.80 ± 84.31 pre vs 277.90 ± 90.24 L/min post) were observed . Whether this PCF change is clinically significant is unclear as normal PCF variability is not known.…”