Extradural diamorphine in the control of pain following lumbar laminectomy.

Catheters were inserted into the extradural space under direct vision at the time of surgery for prolapsed intervertebral disc or lumbar canal stenosis. In the post-operative period, diamorphine (3 mg in 5 ml water) was injected through the catheter when patients requested analgesia. In only four of 49 patients was significant pain relief not achieved after extradural diamorphine injection. In four other patients it was not possible to use this method of analgesia throughout the two post-operative days as planned. As judged by the improved mobility and by grading on a linear analogue pain scale, the quality of analgesia achieved was better than after intramuscular papaveretum (10-20 mg) and extradural diamorphine was requested less frequently. There were no serious side-effects in the patients studied, although the technique was not used in patients over 55 years of age. Extradural diamorphine appeared to be less effective in two patients who had undergone re-explorations.