Lung inflation training using a positive end-expiratory pressure valve in neuromuscular disorders

Abstract

Objective Respiratory muscle weakness causes alveolar hypoventilation and reduced lung compliance in neuromuscular disorders. Lung inflation is important to prevent secondary pulmonary complications however respiratory and laryngeal dysfunction often hamper lung inflation. There is a need for a convenient and lowcost device that enables effective lung inflation. We tested a lung inflation training method using a positive end-expiratory pressure (PEEP) valve. Methods Vital capacity (VC), maximum insufflation capacity (MIC) and peak cough flow (PCF) as well as PEEP lung inflation capacity (PIC) were assessed in 93 neuromuscular patients. Consecutive PIC training was done for 4 months in six tracheostomized Duchenne muscular dystrophy (DMD) patients and PIC was assessed before and after training. Results PIC training was practicable in all participants and no serious adverse events were detected. PIC was significantly higher than VC or MIC in all disorders, although MIC was higher than VC in DMD only. Patients with dysphagia showed lower MIC and PCF compared with non dysphagic patients. PIC was as low as 345±77 mL in tracheostomized DMD patients; however consecutive training increased it up to 619±205 mL. Conclusion The PEEP valve enabled effective lung inflation regardless of laryngeal function. Consecutive training can improve lung condition even in advanced cases. Early introduction of PIC training could be effective at preventing respiratory complications in patients with neuromuscular disorders. © 2012 The Japanese Society of Internal Medicine.