Upper airway microbial colonization in patients with neuromuscular disorders

Inherited neuromuscular disorders (NMD) inevitably result in severe lung volume restriction and cough insufficiency associated with high morbidity and mortality. The aim of this retrospective study was to evaluate whether the airways of patients with NMD are colonized with potential pathogenic microorganisms that might contribute to the pulmonary morbidity in NMD.

In this cross-sectional study, cough swabs were obtained and cultured for microbiological analyses from 77 patients with NMD and different degrees of lung volume restriction and cough insufficiency. Upper airway microbial colonization was compared to lung function parameters and cough peak flow values.

Upper airway microbial colonization with potential pathogenic pathogens was identified in 39/77 (51%) of the subjects. Upper airway microbial colonization was associated with lower forced vital capacity (% pred.) 26.6 ± 19.7 versus 41.8 ± 20.4, P < 0.001 and cough peak flow (l/min) 125 ± 55 versus 207 ± 100, P < 0.001. In the subgroup colonized with potential pathogenic Gram-negative bacteria or Staphylococcus aureus forced vital capacity and cough peak flow remained significantly lower compared with subjects without upper airway colonization (FVC (% pred.): 22.6 ± 16.5 vs 37.9 ± 21.5, P = 0.003; CPF (l/min): 123 ± 60 vs 179 ± 93, P = 0.013).

Severe respiratory compromise in patients with NMD is associated with upper airway microbial airway colonization, which might contribute to respiratory morbidity/insufficiency.