神経筋疾患の呼吸リハビリテーションupdate

An Update on Pulmonary Rehabilitation in Patients with Neuromuscular Disease

はじめに

　筋ジストロフィー，筋萎縮性側索硬化症（amyotrophic lateral sclerosis：以下ALS）などの神経筋疾患患者は呼吸筋力低下による呼吸障害をきたす．1940～50年代には，ポリオによる呼吸筋麻痺に対し，鉄の肺とよばれる体外式人工呼吸器が使用された．その後，気管切開チューブを介した陽圧換気がそれに代わったが，1980年代より鼻マスクやマウスピースを利用した非侵襲的陽圧換気（noninvasive positive pressure ventilation：以下NPPV）が徐々に広まり，現在では神経筋疾患の呼吸不全治療のスタンダードと考えられている．

　神経筋患者の呼吸リハビリテーション（以下，呼吸リハ）は，NPPVに比べ合併症がより多く，生活の質（QOL）も低いとされている^1）気管切開を極力避けるためのコンディショニングが大きな部分を占めており，その有効性は疑いないものであるが，一方でその普及は不十分である．ここではその現状とともに，最近の呼吸リハの進歩についていくつかの知見を紹介する．

Abstract : Pulmonary rehabilitation in neuromuscular disease patients is aimed primarily at avoiding tracheostomy, which carries more complications and is associated with a low quality of life compared with noninvasive positive pressure ventilation (NPPV). 1. Efficacy of NPPV and pulmonary rehabilitation : A recent report by researchers at a Japanese facility described a marked prolongation of life in patients with Duchenne muscular dystrophy who underwent NPPV, pulmonary rehabilitation and the management of heart failure. 2. Guidelines : Although evidence regarding the benefits of pulmonary rehabilitation in neuromuscular disease is insufficient, many statements and guidelines recommending the use of NPPV and pulmonary rehabilitation for several neuromuscular diseases have been published. 3. Spreading use of NPPV and pulmonary rehabilitation : There are patients who have not received the benefit of NPPV even if they are appropriate candidates not only in Japan but also in the United States. Hess described the barriers to NPPV use and considered the means of adopting new technologies. 4. Recent progress : 1) Index of respiratory muscle fatigue : In recent years, respiratory muscle fatigue has been highlighted as a clinical indicator. Several indicators, which can be noninvasively calculated, have been proposed as alternatives to the diaphragmatic tension-time index. 2) Techniques for airway clearance : A new study on the effectiveness of a combination of mechanical insufflation-exsufflation and oscillation has been reported. 5. Conclusions : The wide application of NPPV and pulmonary rehabilitation is becoming more widespread. Despite this, some patients still do not receive the benefits of these techniques. Efforts to improve the existing trend are required.