Article

Spinal cord injury (SCI) patients have respiratory complications
because of abdominal muscle weakness and paralysis, which impair the ability to cough.
This study aims to enhance cough in high-level SCI subjects (n
= 11, SCI at or above T6) using surface electrical stimulation of the abdominal
muscles via 2 pairs of posterolaterally placed electrodes.
METHODS: From total
lung capacity, subjects performed maximum expiratory pressure (MEP) efforts
against a closed airway and voluntary cough efforts. Both efforts were performed
with and without superimposed trains of electrical stimulation (50 Hz, 1 second)
at a submaximal intensity set to evoke a gastric pressure (P(ga)) of 40 cm H(2)O
at functional residual capacity. RESULTS: In the MEP effort, stimulation
increased the maximal P(ga) (from 21.4 +/- 7.0 to 59.0 +/- 5.7 cm H(2)O) and
esophageal pressure (P(es); 47.2 +/- 11.7 to 65.6 +/- 13.6 cm H(2)O). During the
cough efforts, stimulation increased P(ga) (19.5 +/- 6.0 to 57.9 +/- 7.0 cm
H(2)O) and P(es) (31.2 +/- 8.7 to 56.6 +/- 10.5 cm H(2)O). The increased
expiratory pressures during cough efforts with stimulation increased peak
expiratory flow (PEF, by 36% +/- 5%), mean expiratory flow (by 80% +/- 8%), and
expired lung volume (by 41% +/- 16%). In every subject, superimposed electrical
stimulation improved peak expiratory flow during cough efforts (by 0.99 +/- 0.12
L/s; range, 0.41-1.80 L/s). Wearing an abdominal binder did not improve
stimulated cough flows or pressures. CONCLUSIONS: The increases in P(ga) and PEF
with electrical stimulation using the novel posterolateral electrode placement
are 2 to 3 times greater than improvements reported in other studies. This
suggests that posterolateral electrical stimulation of abdominal muscles is a
simple noninvasive way to enhance cough in individuals with SCI.

Langue : ANGLAIS