부산대학교 도서관

BACKGROUND: Manual and mechanical cough-augmentation techniques can improve peak cough flow (PCF) in patients with respiratory insufficiency caused by neuromuscular disease. METHODS: We studied cough-augmentation techniques in 179 clinically stable patients with various neuromuscular diseases. We measured vital capacity (VC), maximum expiratory pressure (MEP), and PCF, with and without 3 cough-augmentation techniques: manually assisted cough (MAC); breath-stacking (in a subgroup of 60 patients receiving noninvasive mechanical ventilation); and breath-stacking in combination with MAC (also in the 60-patient subgroup). We analyzed the data with the receiver operating characteristic (ROC), to predict the lower limits (assisted PCF ≥ 180 L/min) and upper limits (assisted PCF < unassisted PCF) of effectiveness of the 3 cough-augmentation techniques. RESULTS: The lower limit of effective assisted cough with MAC, breath-stacking, and breath-stacking plus MAC was best predicted by VC > 1,030 mL (ROC 0.86, P < .001), VC > 558 mL (ROC 0.92, P < .001), and VC > 340 mL (ROC 0.90, P < .001). The upper limit of effective MAC was best predicted by MEP > 34 cm [H.sub.2]O (ROC 0.89, P < .001), whereas the ROC prediction of the upper limit of effective cough with breath-stacking and with breath-stacking plus MAC was not better than random. With each of the cough-augmentation techniques the benefits decreased linearly with increasing MEP and VC (P < .001). Compared to MAC and breath-stacking alone, breath-stacking plus MAC best improved unassisted PCF (P < .001). CONCLUSIONS: In clinically stable patients with neuromuscular diseases, the effectiveness of cough-augmentation techniques can be predicted with measurements of maximum respiratory capacity. Patients with VC > 340 mL and MEP < 34 cm [H.sub.2]O would optimally benefit from the combination of breath-stacking plus manually assisted cough to improve PCF to > 180 L/min. Key words: breath-stacking, airway clearance, chest physiotherapy, cough, cough augmentation, hyperinflation, neuromuscular, noninvasive ventilation, mucus clearance.
Introduction In the last decade, quality of life and survival have substantially increased among patients with neuromuscular disease receiving home mechanical ventilation. (1-3) These patients typically have cough impairment due [...]