Intrathecal opioid treatment for chronic non-malignant pain: a 3-year prospective study.

Intrathecal (IT) opioid therapy is a treatment alternative for patients with severe chronic non-malignant pain. Several uncontrolled retrospective and prospective outcome studies have suggested a benefit in chronic non-malignant pain patients, but uncertainties about patient selection in these studies weaken the results. This study evaluated long-term outcome of IT opioid therapy in chronic non-malignant pain prospectively, and included two comparative groups to improve understanding of selection criteria and relative severity of intrathecal pump recipients (PRs). The study subjects included 38 PRs while the comparative groups included 31 intrathecal candidates who either had an unsuccessful trial, or declined the IT therapy, and another group of 41 newly referred patients. The following data were analyzed at study entry, and at 6 monthly intervals for a 3-year period: Symptom Check List 90 (SLC-90), SF-36 Health survey, Beck Depression Inventory, McGill Pain Questionnaire (short form), Oswestry Disability Index, Pain Drawings and Pain rating on visual analogue scale. Data analysis suggests the study group of PRs had improvements in pain, mood, and function from baseline to 36 months. These same parameters improved among new referrals (less severe patients receiving conservative pain management) while non-recipients significantly worsened. Although PRs improved, they were still worse off at 36 months than new referrals were at baseline. The study showed that when patients with extremely severe pain problems are selected as pump candidates, they will likely improve with the therapy, but their overall severity of pain and symptoms still remains high.