Approaches to Cough Peak Flow Measurement With Duchenne Muscular Dystrophy

• Published in: Respiratory care 2018-12, Vol.63 (12), p.1514-1519
• Main Authors: Kikuchi, Kazuto, Satake, Masahiro, Kimoto, Yusuke, Iwasawa, Satomi, Suzuki, Ryohei, Kobayashi, Michio, Wada, Chizu, Shioya, Takanobu
• Format: Article
• Language: English
• Subjects: Activities of daily living; Care and treatment; Cough; Duchenne muscular dystrophy; Health monitors; Muscular dystrophy
• ISSN: 0020-1324; 1943-3654
• DOI: 10.4187/respcare.06124

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. 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. 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 ( < .001) for CPF (peak flow meter) and CPF (spirometer) and r = 0.17 ( = .17) in CPF (MI-E) and CPF (spirometer), respectively. MI-E + assisted CPF was the highest. The CPF measured with the peak flow meter suggested underestimation.