Evidence-based medicine depends on the existence of controlled clinical trials that establish the safety and efficacy of specific therapeutic techniques. Many interventions in clinical practice have achieved widespread acceptance despite little evidence to support them in the scientific literature; the critical appraisal of these interventions based on accumulating experience is a goal of medicine. To clarify the current state of knowledge concerning the use of various drugs for intraspinal infusion in pain management, an expert panel conducted a thorough review of the published literature. The exhaustive review included 5 different groups of compounds, with morphine and bupivacaine yielding the most citations in the literature. The need for additional large published controlled studies was highlighted by this review, especially for promising agents that have been shown to be safe and efficacious in recent clinical studies.

Consensus guidelines developed by an expert panel are helpful to clinicians when there is variation in practice and lack of a firm evidence base for an intervention, such as intraspinal therapy for pain. An internet-based survey of practitioners revealed remarkable variation in practice patterns surrounding intraspinal therapy. This prompted an interdisciplinary panel with extensive clinical experience in intraspinal infusion therapy to evaluate the results of the survey, the systematic reviews of the literature pertaining to this approach, and their own clinical experience with long-term spinal infusions. The panel proposed a scheme for the selection of drugs and doses for intraspinal therapy, and suggested guidelines for administration that would increase the likelihood of a successful outcome. These expert panel guidelines were designed to provide an initial structure for clinical decision making that is based on the best available evidence and the perspectives of experienced clinicians.

Abstract:The Pain Medication Questionnaire (PMQ) was designed to assess the risk for opioid medication misuse in chronic pain patients. A preliminary study showed a positive relationship between higher PMQ scores and concurrent measures of substance abuse, psychopathology, and physical/ life-functioning. Using a larger sample size, the present study sought to replicate these findings, and to expand upon them by examining the relationship between PMQ scores and various treatment outcomes. The PMQ was administered to 271 newly evaluated chronic pain patients who were subsequently re-evaluated immediately post-treatment, as well as six months following discharge. Subgroups were then formed according to the lowest (L-PMQ), middle (M-PMQ), and highest (H-PMQ) one-third of PMQ total scores. It was found that the H-PMQ group was 2.6 times more likely to have a known substance-abuse problem, 3.2 times more likely to request early refills of prescription medication, and 2.3 times more likely to drop out of treatment, as compared to the L-PMQ group. They also had diminished biopsychosocial functioning. In addition, at six months following discharge, patients who completed the program experienced a significant decrease in PMQ scores over time relative to those patients who were unsuccessfully discharged from the program or who dropped out. This study represents the second stage in the development of a psychometrically sound screening tool for measuring risk for opioid medication misuse among chronic pain patients, and findings suggest the long-term utility of the PMQ in identifying patients who are more likely to complete and benefit from a pain management program.

This study retrospectively investigated the predictive value of intrathecal narcotic trials for long-term drug utilization via implantable pumps in chronic non-cancer patients. Data were derived from 86 patients who were categorized according to the intrathecal narcotic dose that resulted in the optimal trial response. The response during the trial period and the pattern of long-term utilization of morphine was studied, as was the impact of age, gender and diagnosis. The analysis revealed that low dose responders had lower daily dose requirements at 18 months than standard dose and high dose responders. It also showed that women had lower total daily dose requirements at 18 and 24 months and that individuals over 65 years of age had lower total daily dose requirements at 18 months. A trend toward a disproportionately higher use of adjuvant drugs and narcotic substitutions was found among high dose responders, while a trend toward a disproportionately higher total daily dose was found among cervicalgia patients. The findings indicate that the responsiveness to an intrathecal narcotic during a trial, along with the diagnosis at the time of implantation, and the patient's age and gender can shed light on the long-term utilization of intrathecal analgesics in chronic non-cancer patients. This information may be used to better select patients and design trials that more closely reflect long-term drug utilization.