Postoperative transcutaneous electrical nerve stimulation (TENS) in shoulder surgery (randomized, double blind, placebo controlled pilot trial)

Background. The aim of this study was to determine whether 3 days of TENS t herapy postoperatively after shoulder operations would result in better pai n relief and/or reduced analgesic intake when compared to placebo. Method. The study was carried out randomized, double-blind and placebo cont rolled. Thirty patients were randomized to two groups. The verum group rece ived TENS SM1AKS 80 Hz 6 mA and the placebo group received TENS SM1AKS 80 H z 0 mA. The pain was assessed pre-operatively using the Hamburg Pain Adject ive List. Premedication and Anasesthesia were standardized. TENS was applie d to the patients immediately postoperatively for 8 hours and then on the f ollowing days 5 times daily for 45 minutes. The effectiveness was evaluated postoperatively using a visual analogue scale (rest, activity), the Hambur g Pain Adjective List and postoperative analgesic consumption. Results. The visual analogue scale at rest and on activity showed no signif icant difference between the groups. Postoperative analgesic consumption of morphine hydrochloride in the first 24 hours was at time 8 hours postopera tive significantly and at all other time points markedly less in the verum group compared to the placebo group. The sensory secondary scale score of t he "Hamburg Pain Adjective List" was significantly lower postoperatively co mpared to preoperatively in the verum group. Conclusion. We were able to show in this study that TENS applied postoperat ively after shoulder surgery clearly reduced analgesic consumption in the f irst 72 hours. Furthermore there was a significant difference in the pain s cores using the "Hamburg Pain Adjective List" in favour of the verum group. TENS applied postoperatively is a effective, simple modality with few side -effects.