Effect of electro-acupuncture on reducing opioid consumption in patients with chronic pain: a randomised controlled clinical trial

Objectives: Electro-acupuncture (EA) has been demonstrated to be effective in reducing post-operative acute consumption of opioid-like medications (OLM) by previous studies. This effect has not been examined in patients with chronic pain. In this thesis, a randomised, double-blind, sham acupuncture-controlled study was reported. The trial aimed to evaluate the effect of EA in reducing OLM consumption in patients with chronic non-malignant pain. Methods: Thirty-five patients were recruited from a multidisciplinary pain management clinic in Melbourne. After a two-week baseline assessment, participants were randomly assigned to one of the two groups by a computer generated randomisation sequence: real EA (REA, n = 17) or sham EA (SEA, n = 18). The REA group received 2/100 Hz EA stimulation on two pairs of acupoints (Zusanli ST36 and Fenglong ST40 on one leg and Hegu LI4 and Quchi LI11 on one arm) and manual acupuncture on an additional five chosen acupoints for 30 minutes. The SEA group received superficial needling on non-acupoints without Deqi sensation or electrical stimulation. Both groups received treatment twice a week for six weeks. Participants were followed up for 12 weeks at intervals of four weeks. During the trial, participants were given clear instructions on how to reduce their OLM usage. A researcher telephoned the participants three times during the trial to encourage them to reduce OLM intake. The assessor, researcher and participants were blinded to treatment allocation. Outcome measures: The primary outcome measures included OLM consumption, related side effects, dosage of non-opioid analgesics and the intensity and unpleasantness of pain. These measures were recorded daily for two weeks before the intervention, six weeks during the treatment period and three times during the follow up period. Secondary outcome measures were depression and quality of life as assessed by the Beck Depression Inventory-II (BDI-II) and the Medical Outcome Study 36-Item Short Form (SF-36), respectively. Data were analysed with independent t-tests or analysis of variance (ANOVA) where appropriate and per protocol analysis was employed. Results: Nine participants withdrew from the study. At baseline, the two groups were comparable on all demographic characteristics and major outcome variables except for the average intensity of pain. During the treatment period, the reduction of OLM consumption was more rapid in the REA group (64%) than in the SEA (46%) (ANOVA, p less than 0.05). The effect was maintained for four weeks in the REA group. There were no differences in the improvement of all other measures between the two groups. The incidence of EA-related adverse events (AEs) per treatment was 21% and 10% in the REA and SEA groups, respectively. All AEs were minor. Over 90% of the participants were satisfied with the treatments given and would recommend EA to others. The blinding was successful. Conclusions: EA could be an effective and safe treatment for reducing OLM consumption for patients with chronic pain, and may be used as an adjunct therapy in chronic pain management. Further studies with larger sample sizes are warranted