Peter Dahm

Clinical experience using intrathecal (IT) bupivacaine infusion in three patients with complex regional pain syndrome type I (CRPS‐I)

Background and aim: To date, there is no reliable method for treating the severe pain and for modifying the natural evolution of CRPS‐I. Therefore, we explored the effect of long‐term IT bupivacaine infusion (with or without buprenorphine) on this syndrome.

Six years of continuous intrathecal infusion of opioid and bupivacaine in the treatment of refractory pain due to intrapelvic extrusion of bone cement after total hip arthroplasty.

Background and Objectives. There is at present no reliable method for long‐term treatment of severe pain following complications of total hip arthroplasty. We explored the longterm use of continuous intrathecal opioid/bupivacaine analgesia in a case not amendable to corrective surgery. Methods. A 77‐year‐old woman, having a total hip arthroplasty, developed refractory nociceptive‐neuropathic pain located at the ventral and dorsal aspects of the left hip. Radiographs showed a mandarine‐sized intrapelvic mass of bone cement adhering to the roof of the acetabular cup. Further surgery had been declined by the surgeon and by the patient. An 18‐gauge Portex intrathecal catheter was inserted, and an intrathecal infusion of 4.75 mg/mL bupivacaine and 0.015 mg/mL buprenorphine was started from a portable Pharmacia‐Deltec (St. Paul, Minnesota) pump. Results. The mean daily doses during the treatment period (more than 6 years up to now) were 37 mg for bupivacaine and 0.114 mg for buprenorphine. The intrathecal treatment gave the patient 85‐100% pain relief. The patient could transport herself in a wheelchair, was able to perform her own hygiene, receive visits, read, watch television, and also shop and visit restaurants. There has been no need to replace the intrathecal catheter. Conclusion. Intrathecal infusion of opioid/bupivacaine can provide satisfactory long‐term analgesia in patients with refractory pain from the hip joint.

Ultralow Dose of Naloxone as an Adjuvant to Intrathecal Morphine Infusion Improves Perceived Quality of Sleep but Fails to Alter Persistent Pain: A Randomized, Double-blind, Controlled Study

Introduction:This randomized, cross-over, double-blind, controlled study of continuous intrathecal morphine administration in patients with severe, long-term pain addresses whether the supplementation of low doses of naloxone in this setting is associated with beneficial clinical effects. Methods:All of the study subjects (n=11) provided informed consent and were recruited from a subset of patients who were already undergoing long-term treatment with continuous intrathecal morphine because of difficult-to-treat pain. The patients were (in a randomized order) also given intrathecal naloxone (40 ng/24 h or 400 ng/24 h). As control, the patients’ ordinary dose of morphine without any additions was used. The pain (Numeric Rating Scale, NRS) during activity, perceived quality of sleep, level of activity, and quality of life as well as the levels of several proinflammatory and anti-inflammatory cytokines in the blood were assessed. The prestudy pain (NRS during activity) in the study group ranged from 3 to 10. Results:A total of 64% of the subjects reported improved quality of sleep during treatment with naloxone at a dose of 40 ng per 24 hours as compared with 9% with sham treatment (P=0.024). Although not statistically significant, pain was reduced by 2 NRS steps or more during supplemental treatment with naloxone in 36% of subjects when using the 40 ng per 24 hours dose and in 18% of the subjects when using naloxone 400 ng per 24 hours dose. The corresponding percentage among patients receiving unaltered treatment was 27%. Conclusions:To conclude, the addition of an ultralow dose of intrathecal naloxone (40 ng/24 h) to intrathecal morphine infusion in patients with severe, persistent pain improved perceived quality of sleep. We were not able to show any statistically significant effects of naloxone on pain relief, level of activity, or quality of life.

Continuous Intrathecal Infusion of Opioid and Bupivacaine in the Treatment of Refractory Pain Due to Postherpetic Neuralgia: A Case Report

This report details the course of a 77‐year‐old patient suffering mild pain from operated tongue cancer and excruciating, intractable pain from thoracic (T6–T8) post‐herpetic neuralgia (PHN), The mouth pain was treated with nonopioid analgesics, as the patient had personal objections to opioid treatment. All the components of the pain from his PHN (continuous burning pain, intermittent lancinating stabbing pain, and tactile allodynia) were successfully treated with an Intrathecal Infusion of buprenorphine (0.03 mg/ml) and bupivacaine (4.75 mg/ml) administered via an externalized intrathecal catheter with the tip located at T9–T10 intervertebral disc. The treatment started three months after the appearance of the herpetic eruption and lasted 294 days until the patient died of malnutrition and the progression of his tongue cancer. During treatment, he experienced satisfactory pain relief from his PHN; the mean visual analogue scores (VASmean), recorded on a scale from 0 to 10, ranged from 1 to 2, compared to 9 to 10 before starting the intrathecal treatment. Analgesia was established with 0.2–0.315 mg/day of intrathecal buprenorphine and 90–100 mg/day of intrathecal bupivacaine. His undisturbed nocturnal sleep increased from 4 to 5–6 hours. The side‐effects from the bupivacaine (urine retention requiring insertion of an indwelling urinary catheter, paresthesias, and mild pareses) were recorded. The patient could ambulate without support while on 90–100 mg/day of intrathecal bupivacaine. During a series of high‐pressure oxygen treatments in a pressure chamber to treat an infection at the site of his tumor, the intrathecal infusion was interrupted. Thus, repeated observation of the intervals of severe pain and of analgesia were possible.

Long-Term Intrathecal Infusion of Opioid and/or Bupivacaine in the Prophylaxis and Treatment of Phantom Limb Pain.

Introduction and Methods. A prospective, open case study was performed on 37 patients, given intrathecal (IT) bupivacaine alone or bupivacaine/opioid combinations for refractory pain located in the extremities to explore the potential of this therapy for prophylaxis against post‐amputation pain (PLP) and/or the treatment of severe, established PLP. Intrathecal infusions were administered before, during, and after amputation, as an attempt to prevent PLP (“prophylaxis group”; n = 21), or to relieve existing severe PLP after previous amputations (“treatment group”; n = 16).

Evaluation of the cost-effectiveness of buprenorphine in treatment of chronic pain using competing EQ-5D weights

Abstract Background and aims Chronic pain is a life altering condition and common among elderly persons. The 7-day buprenorphine patch could be a suitable treatment for managing chronic pain of moderate severity in elderly patients in Sweden. The objective of this analysis was to investigate the cost-effectiveness of the 7-day buprenorphine patch, versus no treatment, in patients >50 years old who suffer from moderate pain in a health economic perspective. An additional aim was to evaluate how the cost-effectiveness is affected by the choice of EQ-5D weights. Methods The annual treatment cost and the potential gains in health-related quality of life (HRQoL) of buprenorphine, compared to no treatment, were evaluated. Original EQ-5D data were collected from four clinical reference studies at baseline and at the final visit. Treatment effects on HRQoL were then assessed using both UK and Swedish EQ-5D weights. Annual treatment costs were calculated based on costs of physician visits and pharmaceuticals. The optimal treatment dose was 10-15 μg/h and the analysis was hence performed on both a 10- and a 15 μg/h buprenorphine patch. Results The analysis of buprenorphine treatment resulted in improved HRQoL in all reference studies, irrespective of choice of EQ-5D weight set. The change in quality adjusted life years (QALYs) varied with a gain of 0.042-0.118 using the UK weights and 0.020-0.051 with the Swedish weights. The average annual treatment cost was SEK14454 for the 10μg/h patch and SEK17 017 for the 15 μg/h patch, while cost for the no-treatment alternative was SEK 9 960. The base case incremental cost-effectiveness ratios (ICER) with the UK weights were SEK 40000-SEK 170000 and SEK 90000-SEK 350000 when applying the Swedish weights. The corresponding ICER-span in the sensitivity analysis was SEK 15 000-SEK 400 000 when applying the UK weights and SEK 30 000-SEK 840 000 with the Swedish weights (SEK 100 is about €11). Conclusions The results imply that the 7-day buprenorphine patch may be a cost-effective treatment of moderate chronic pain in patients over 50 years of age. The UK and the Swedish EQ-5D weights generated vastly different HRQoL estimates but buprenorphine remains cost-effective regardless choice of weight set.