Pursed lips breathing improves ventilation in myotonic muscular dystrophy.
OBJECTIVE
To determine the effects of pursed lips breathing on ventilation, chest wall mechanics, and abdominal muscle recruitment in myotonic muscular dystrophy (MMD).


METHODS
Before-after trial.


METHODS
University hospital pulmonary function laboratory.


METHODS
Eleven subjects with MMD and 13 normal controls.


METHODS
Pursed lips breathing.


METHODS
Electromyographic (EMG) activity of the transversus abdominis, external oblique, internal oblique, and rectus abdominis was recorded with simultaneous measures of gastric pressure, abdominal plethysmography, and oxygen saturation. Self-reported sensations of dyspnea, respiratory effort, and fatigue were recorded at the end of each trial.


RESULTS
Pursed lips breathing and deep breathing led to increased tidal volume, increased minute ventilation, increased oxygen saturation, reduced respiratory rate, and reduced endexpiratory lung volume. Dyspnea, respiratory effort, and fatigue increased slightly with pursed lips breathing. EMG activity of the transversus abdominis and internal oblique muscles increased in MMD only and was associated with an increase in gastric pressure.


CONCLUSIONS
Pursed lips breathing and deep breathing are effective and easily employed strategies that significantly improve tidal volume and oxygen saturation in subjects with MMD. Abdominal muscle recruitment does not explain the ventilatory improvements, but reduced end-expiratory lung volume may increase the elastic recoil of the chest wall. Further clinical studies are needed to ascertain if the ventilatory improvements with pursed lips breathing and deep breathing improve pulmonary outcomes in MMD.
Ugalde
V
V
Department of Physical Medicine and Rehabilitation, School of Medicine, University of California, Davis, USA.
Breslin
E H
EH
Walsh
S A
SA
Bonekat
H W
HW
Abresch
R T
RT
Carter
G T
GT
D000009:Abdominal Muscles / Q000503:physiopathology; D000328:Adult; D001945:Breathing Exercises; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000503:physiopathology* / Q000534:rehabilitation*; D011446:Prospective Studies; D012119:Respiration; D012129:Respiratory Function Tests; D013990:Tidal Volume