Clinical experience of long–term treatment with epidural and intrathecal opioids – a nationwide survey

Long–term use of spinal opioids to treat chronic severe pain is widely established. However, the indications, shortcomings and complications of the method have not been completely described. Experience with spinal opioids was analysed for the period 1979–1984 in a nationwide Swedish survey. Out of 93 anaesthesia departments, 69 used the method. Approximately 750 patients were treated with epidural morphine for an average duration of 124 days (3–450). Eighteen patients were treated with intrathecal morphine for an average period for 47 days (3–90). The intrathecal approach was used in all clinics because of failure of the epidural route. In only one department was the intrathecal approach used as the primary route of therapy, depending on the mechanism of pain. The highest daily morphine dose was 480 mg and 50 mg for epidural and intrathecal routes, respectively. The patients given the highest dosages were not necessarily those subjected to the longest treatment. The need for increased dosage seems to be related not only to changes in receptor sensitivity but also to changes in pain mechanisms. No case of threatening ventilatory depression was reported. Thirty–two departments had treated a few patients with chronic non–cancer pain conditions. Initial results were considered “excellent” in H departments, but at follow–up results were excellent in only one department. In addition to dislocation, occlusion of the catheters or leakage, injection pain was an obstacle to successful treatment. Pruritus, urinary retention, and local infections were not reported as significant problems, but one case of meningitis was reported.