ABSTRACT
PURPOSE: Mechanically assisted coughing (MAC) is an airway clearance method in which the thorax/abdomen is compressed in synchronization with mechanical insufflation-exsufflation (MI-E). MAC can be performed with manual assistance at the upper thorax (MAC-UT), lower thorax (MAC-LT), and upper thorax + abdomen (MAC-UT/A). This study aimed to determine the most effective approach under different conditions (air stacking or tracheostomy) in patients with neuromuscular disorders (NMDs). METHODS: The study included 34 patients with NMDs. The patients were categorized into air stacking group (n=15), no air stacking group (n=9), and tracheostomy/tracheostomy positive-pressure ventilation (TPPV) group (n=10). RESULTS: In each group, the cough peak flow (CPF) at 75% of the forced vital capacity (VÌ75), VÌ50, VÌ25, and VÌ10 were investigated during the approaches. In the air stacking group, the CPF was higher with MAC-UT, MAC-LT, and MAC-UT/A than with MI-E (p < 0.05). Additionally, VÌ75 was higher with MAC-LT and MAC-UT/A than with MI-E (p < 0.05 and p < 0.01, respectively). In the no air stacking group, VÌ75 was higher with MAC-UT/A than with MI-E (p < 0.05). In the tracheotomy/TPPV group, there were no significant differences. CONCLUSIONS: MAC approaches, especially MAC-LT and MAC-UT/A, are preferred in air stacking patients. However, in tracheostomy/TPPV patients, the CPF might not increase with MAC.
ABSTRACT
BACKGROUND: Manually-assisted coughing and mechanical insufflation-exsufflation (MI-E) are commonly used in patients with Duchenne muscular dystrophy (DMD). Few studies have compared cough peak flow (CPF) with manually-assisted coughing to other methods, such as MI-E + manually-assisted coughing. In addition, few studies have reported the reliability of the measured CPF values. This study aimed to compare CPF with different cough-assistance methods and to examine the reliability of CPF data. METHODS: The study included 12 subjects with DMD (mean age, 34 ± 8 y). CPF, CPF + manually-assisted coughing (assisted CPF), maximum insufflation capacity (MIC) + CPF (MIC-CPF), MIC + manually-assisted coughing (MIC+assisted CPF), MI-E (MI-E-CPF), and MI-E + assisted CPF were measured. A spirometer was used to compare CPF measurements obtained with each of the cough-assist techniques. The reliability of the measured CPF values was analyzed using Bland-Altman analysis. RESULTS: CPF was 59 ± 34 L/min, assisted CPF was 113 ± 32 L/min, MIC-CPF was 170 ± 30 L/min, MIC+assisted CPF was 224 ± 62 L/min, MI-E-CPF was 199 ± 40 L/min, and MI-E + assisted CPF was 240 ± 38 L/min. A fixed and proportional bias was found in the CPF measurements made with the peak flow meter and the spirometer. The average 95% CI in the difference between peak flow meter, MI-E, and CPF obtained using the spirometer were -7.45 to -1.95 and -1.45 to 4.95, respectively. Test for correlation was r = 0.54 (P < .001) for CPF (peak flow meter) and CPF (spirometer) and r = 0.17 (P = .17) in CPF (MI-E) and CPF (spirometer), respectively. CONCLUSION: MI-E + assisted CPF was the highest. The CPF measured with the peak flow meter suggested underestimation.
