Acute Effects of Air Stacking Versus Glossopharyngeal Breathing in Patients with Neuromuscular Disease.

Objective: To compare the effects of Air Stacking (AS) and Glossopharyngeal Breathing (GPB) on the Maximum Insufflation Capacity (MIC) in patients with Neuromuscular Disease (NMD). Methods: We design a randomized cross-over study. Children and adolescents with NMD who were users of non-invasive mechanical ventilation were recruited. Vital capacity (VC) and MIC were measured before and after the intervention with AS and GPB. Values were compared pre- and post-intervention and were considered statistically significant if p <0.05. Results: We selected 14 patients with a median age of 12.5 years (range 9-18) with the following diagnoses: Duchenne Muscular Dystrophy (7), Spinal Muscular Atrophy Type II (3), Spinal Cord Injury (1) and Congenital Myopathies (3). The median baseline VC was 1325 ml (CI 1084-1594 ml). AS improved the VC to 1930 mL (CI 1630-2434 mL, p<0.001), and GPB increased the VC to 1600 mL (CI 1370-1960 mL, p=0.001). There was a significant difference of 290 mL (CI 168-567 mL, p<0.002) between both techniques. Conclusion: The air stacking and glossopharyngeal breathing were both effective in increasing the maximum insufflation capacity, but air stacking resulted in a greater increase in MIC.

Assisted Cough and Pulmonary Compliance in Patients with Duchenne Muscular Dystrophy

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+/-780cc) was higher than that of VCs (1502+/-765cc) (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.

Analysis of Pulmonary Mechanics and the Factors for Coughing in Duchenne Muscular Dystrophy

OBJECTIVE: To investigate the pathologic pulmonary mechanics and analyze the factors affecting cough ability in patients with Duchenne muscular dystrophy (DMD). METHOD: Thirty-one patients with DMD were investigated. The vital capacity (VC), maximum insufflation capacity (MIC), maximal inspiratory (MIP), and expiratory pressure (MEP) were measured. Unassisted peak cough flow (UPCF) and assisted PCF at three different conditions were evaluated. RESULTS: The mean value of MICs (1, 873 +/- 644 cc) was higher than that of VCs (1, 509 +/- 640 cc). MIP and MEP were 48.8 +/- 21.4% and 29.5 +/- 19.5% of predicted normal value respectively. MIP was correlated with UPCFs as well as MEP. All of three assisted cough methods showed significantly higher value than unassisted method (p<0.01). The manual assisted PCFs at MIC significantly exceeded those produced by manual assisted or PCFs at MIC. The positive correlation between the MIC-VC difference and PCF at MIC-UPCF difference was seen (p<0.01). CONCLUSION: Inspiratory muscle strength and the preservation of pulmonary compliance is important for the development of effective cough as well as expiratory muscle power. Thus, the clinical implication of the inspiratory phase in assisting a cough should be emphasized.