Cough peak flow with different mechanically assisted coughing approaches under different conditions in patients with neuromuscular disorders

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 (V75), V50, V25, and V10 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, V75 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, V75 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.