Transcutaneous electrical nerve stimulation in the management of acute postoperative pain

Twenty patients undergoing decompressive lumbar laminectomy were randomly allocated, in a double-blind manner, to receive active or inactive transcutaneous electrical nerve stimulation (TENS) as part of the management of their postoperative pain. All patients received the same non-narcotic general anaesthetic. The efficacy of the TENS was assessed by using a patient-controlled analgesia system (PRODAC) which delivered morphine i.v. This system recorded the number of demands for analgesia and the total dose administered in the first 24 h. In addition, plasma morphine concentrations were measured hourly for the first 6 h and again at 24 h. There was no statistical difference between the two groups in the number of patient demands for analgesia, morphine dose or plasma morphine concentration. TENS offered no advantage over a placebo in the management of acute postoperative pain in these patients.