Lau KS , Jones AY.  
Physiotherapy,
The Hong Kong Polytech University,
Kowloon , Hong Kong.
rsajones@polyu.edu.hk.  

Questions: What is the immediate effect of a single 45-minute session of transcutaneous electrical nerve stimulation over acupoints (Acu-TENS) on lung function and dyspnoea in patients with chronic obstructive pulmonary disease? Design: Randomised, placebo-controlled trial with concealed allocation, participant blinding, assessor blinding, and intention-to-treat analysis. Participants: Forty-six ambulatory patients with a mean age of 75 years, with stage I or II chronic obstructive pulmonary disease, and with no previous experience of TENS or acupuncture.

Intervention: The experimental group received 45 minutes of Acu-TENS over acupoint Ex-B1 bilaterally (0.5 'cun' lateral to the spinous process of the 7(th) cervical vertebra) while the control group received placebo-TENS with identical electrode placement but no electrical output despite a flashing light indicating stimulus delivery. Outcome measures: Lung function was measured as FEV1 and FVC while dyspnoea was measured using a shortness of breath 100-mm visual analogue scale. Results: After 45 minutes of Acu-TENS, the experimental group had increased FEV1 by 0.12 litres (95% CI 0.07 to 0.15) and decreased dyspnoea by 10.7 mm (95% CI -13.9 to -7.6) more than the control group. The effect on FVC was only small (mean difference 0.05 litres , 95% CI -0.01 to 0.10).

Conclusion: Acu-TENS may be a useful non-invasive adjunctive intervention in the management of dyspnoea in patients with chronic obstructive pulmonary disease. This study suggests that the effect of long-term Acu-TENS warrants further investigation.