Rehabilitation of swallowing and cough functions following stroke: an expiratory muscle strength training trial

Archives of Physical Medicine and Rehabilitationに「Rehabilitation of swallowing and cough functions following stroke: an expiratory muscle strength training trial」 （Karen Wheeler Hegland, Paul W. Davenport, Alexandra E. Brandimore, Floris F. Singletary, Michelle S. Troche）が掲載されている。

Abstract

Objective
To determine the effect of expiratory muscle strength training on both cough and swallow function in stroke patients.

Design
Prospective pre-post intervention trial with one participant group.

Setting
Two outpatient rehabilitation clinics

Participants
Fourteen adults with a history of ischemic stroke in the preceding 3 – 24 months participated in this study.

Intervention
Expiratory muscle strength training (EMST). The training program was completed at home and consisted of 25 repetitions per day, 5 days per week, for 5 weeks.

Main outcome measures
Baseline and post-training measures were: maximum expiratory pressure, voluntary cough airflows, reflex cough challenge to 200μM capsaicin, sensory perception of urge-to-cough, and fluoroscopic swallow evaluation. Repeated measures and one-way analyses of variance were used to determine significant differences pre/post training.

Results
Maximum expiratory pressure increased in all participants by an average of 30cmH2O post training. At baseline, all participants demonstrated a blunted reflex cough response to 200 μM capsaicin. Following 5 weeks of training, measures of urge to cough and cough effectiveness increased for reflex cough, however voluntary cough effectiveness did not increase. Swallow function was minimally impaired at baseline, and there were no significant changes in the measures of swallow function post training.

Conclusions
Expiratory muscle strength training improves both expiratory muscle strength, reflex cough strength and urge-to-cough. Voluntary cough and swallow measures were not significantly different post training. It may be that stroke patients benefit from the training for up-regulation of reflex cough and thus improved airway protection.

　EMSTについては、日本摂食嚥下リハ学会の「訓練法のまとめ（2014 版）」に
「器具を用いることにより呼吸機能を高める方法で，その作用機序は器具により異なる．吸気
抵抗負荷法では，最大吸気圧の 60～80% まで段階的に増強することが勧められているが，30%
でも効果を認めるという報告もある．頻度などにはまだ一定の見解がない．」と述べられている。
以前も述べたが、呼気筋トレーニングは嚥下機能を高めるというより、誤嚥性肺炎予防に役立つものである。
　今回の論文はstrokeを対象としているが、日本であれば介護予防に取り入れることで、誤嚥性肺炎リスクを減らせるのではないかと考えられた。