Jane L. Southall

A Narrative Review of the Impact of Disbelief in Chronic Pain

Although the experience of being believed is frequently alluded to in chronic pain literature, few studies have specifically explored this phenomenon and even fewer reviews have been offered. This narrative review sought to explore the wider social context in which individuals with chronic pain may experience disbelief toward their pain. Articles were obtained through a search of eight databases and a hand search of the references of full-text papers. Key results within the articles were noted and integrated to form three main themes: stigma, the experience of isolation, and the experience of emotional distress. The experience of stigma can occur in a number of ways. It may be through actual or perceived encounters with others; it can be through the use of psychologic explanations of pain; it can come through a perceived challenge to ones integrity and subsequently affect an individuals identity; and such stigma may be influenced by negative female stereotypes. The loss of relationships associated with being disbelieved can lead to the experience of isolation. This may be self-initiated, particularly when an individual has been given a contested diagnosis. Finally, disbelief can lead to emotional distress. This can take the form of guilt, depression, and anger. Throughout the article, implications for health care professionals, working with individuals living with chronic pain, are discussed.

Intrathecal inflammatory masses: is the yearly opioid dose increase an early indicator?

Objectives:  The objective of this study is to investigate the association between intrathecal drug, flow rate, drug concentration, and drug dose with the formation of intrathecal inflammatory masses.

Long-term intrathecal drug administration for chronic nonmalignant pain.

Background: Chronic pain of nonmalignant origin requires effective long-term treatments, as for many patients pain management will be necessary throughout the rest of their lives. Intrathecal drug delivery systems (IDDS) have become a recognized therapy for the management of severe and otherwise intractable chronic pain. However, it is still not clear whether this treatment can be effective for periods up to 10 years or longer, given the paucity of long-term follow-up. This study sought to examine the effectiveness of IDDS following an average of 13 years postimplantation. Methods: Twenty patients participated in a longitudinal study with an average follow-up of 13.5 years (range: 10.4 to 17.9) after IDDS implantation. Investigation was carried out by means of a questionnaire before IDDS and after an average of 4 and 13 years of IDDS therapy. Assessment of pharmacological data and complications/side effects was performed. Results: Statistically significant improvements between baseline and 4-year assessment were observed for the following sensory and psychosocial variables: pain intensity, pain relief, coping, self-efficacy, depression, quality of life, housework, mobility, sleep, and social life (all P<0.001). No statistically significant changes were detected between assessments at averages of 4 and 13.5 years. Conclusions: This study, with one of the longest follow-up intervals reported in the IDDS literature, shows that IDDS has the potential to be a life-long pain management solution in appropriately selected patients with chronic nonmalignant pain.

Hypogonadism and low bone mineral density in patients on long-term intrathecal opioid delivery therapy

Objectives This study aimed to investigate the hypothalamic-pituitary-gonadal axis in a sample of male patients undertaking intrathecal opioid delivery for the management of chronic non-malignant pain and the presence of osteopaenia and/or osteoporosis in those diagnosed with hypogonadism. Design Observational study using health data routinely collected for non-research purposes. Setting Department of Pain Management, Russells Hall Hospital, Dudley, UK. Patients Twenty consecutive male patients attending follow-up clinics for intrathecal opioid therapy had the gonadal axis evaluated by measuring their serum luteinising hormone, follicle stimulating hormone, total testosterone, sex hormone binding globulin and calculating the free testosterone level. Bone mineral density was measured by DEXA scanning in those patients diagnosed with hypogonadism. Results Based on the calculated free testosterone concentrations, 17 (85%) patients had biochemical hypogonadism with 15 patients (75%) having free testosterone <180 pmol/L and 2 patients (10%) between 180 and 250 pmol/L. Bone mineral density was assessed in 14 of the 17 patients after the exclusion of 3 patients. Osteoporosis (defined as a T score ≤−2.5 SD) was detected in three patients (21.4%) and osteopaenia (defined as a T score between −1.0 and −2.5 SD) was observed in seven patients (50%). Five of the 14 patients (35.7%) were at or above the intervention threshold for hip fracture. Conclusions This study suggests an association between hypogonadism and low bone mass density in patients undertaking intrathecal opioid delivery for the management of chronic non-malignant pain. Surveillance of hypogonadism and the bone mineral density levels followed by appropriate treatment may be of paramount importance to reduce the risk of osteoporosis development and prevention of fractures in this group of patients.

Randomized Double-Blind Sham-Controlled Crossover Study of Short-Term Effect of Percutaneous Electrical Nerve Stimulation in Neuropathic Pain

BACKGROUND Percutaneous electrical nerve stimulation (PENS) is an electrical neuromodulation technique that has shown its therapeutic potential in various chronic pain conditions over the past few years, but well-blinded controlled studies are lacking. PATIENTS AND METHODS A randomized double-blind sham-controlled crossover trial on 31 patients with chronic pain with surface hyperalgesia to investigate the efficacy of PENS. RESULTS For the active PENS therapies, the median numerical rating scale (NRS) for pain changed from 7.5 (standard deviation [SD] ± 1) (range 6-10) before therapy to 0.5 (range 0-8.5) after therapy (Z = -4.206, P < 0.0005 [two-tailed]). The mean pain pressure threshold (PPT) measured with the von Frey aesthesiometer changed from 202 gm (SD ± 137 gm) (range 55-800 gm) before therapy to 626 gm (SD ± 228 gm) (range 45-800 gm) after therapy (Z = -4.373, P < 0.0005 [two-tailed]). There was a statistically significant difference between the changes in NRS for the active (3.9 [±3.2][0-8]) compared with the sham (0.1 [±0.4][0-1.5]) therapies, U = 40, Z = -3.484, P < 0.0001 (two-tailed). There was a statistically significant difference between the changes in PPT for the active (310 gm [±267 gm][0-670 gm]) compared with the sham (8 gm [±4 gm][0-15 gm]) therapies, U = 48.5, Z = -2.699, P = 0.007 (two-tailed). CONCLUSION PENS therapy appears to be effective in providing short-term pain relief in chronic pain conditions. Studies, involving larger sample sizes and longer follow-up are recommended.

Randomised, double-blind controlled trial by dose reduction of implanted intrathecal morphine delivery in chronic non-cancer pain

Objective This study aimed to investigate the efficacy of intrathecal morphine in the long term by hypothesising that a reduction of the intrathecal opioid dose following long-term administration would increase the level of pain intensity. Design Randomised, double-blind, controlled, parallel group trial. Setting Department of Pain Management, Russells Hall Hospital, Dudley, UK. Participants 24 patients with non-cancer pain implanted with morphine reservoirs were assessed for eligibility. Interventions Participants were randomly allocated to one of two parallel groups in which one of the groups had no change in morphine dose and the other group had a small reduction (20%) in dosage every week during a 10-week follow-up. Outcome Primary outcomes were visual analogue scale (VAS) pain score change and withdrawal from the study due to lack of efficacy. Results 9 of the patients assessed for eligibility declined to participate in the study. 15 patients were randomised to control (n=5) or intervention (n=10) and included in an intention-to-treat analysis. Owing to worsening of pain, seven patients withdrew from the study prematurely. None knew prior to withdrawal which arm of the study they were in, but all turned out to be in the dose-reduction arm. The calculation of dropout rates between groups indicated a significant statistical difference (p=0.026) and recruitment was ceased. The VAS change between baseline and the last observation was smaller in the control group (median, Mdn=11) than in the intervention group (Mdn=30.5), although not statistically significant, Z=−1.839, p=0.070; r=−0.47. Within groups, VAS was significantly lower at baseline (Mdn=49.5) than at the last observation (Mdn=77.5) for the reduction group, Z=−2.805, p=0.002; r=−0.627 but not for the control group (p=0.188). Conclusions This double-blind randomised controlled trial of chronic intrathecal morphine administration suggests the effectiveness of this therapy for the management of chronic non-cancer pain. However, owing to the small number of patients completing the study (n=8), further studies are warranted. Trial registration International Standard Randomised Controlled Trials Centre (ISRCTN 33733462).

Multiple Lead Spinal Cord Stimulation for Chronic Mechanical Low Back Pain: A Comparative Study with Intrathecal Opioid Drug Delivery

The objective of this paper is to assess the outcome of implanted multiple thoracolumbar lead spinal cord stimulation (SCS) in mechanical back pain without prior spinal surgery. These results are compared with intrathecal opioid drug delivery (ITDD). An anonymous third party patient questionnaire study of pain relief, function and psychosocial quality of life measures (recorded on 11‐point numerical rating scales) for 12 patients with SCS and 13 with ITDD was used. Pain was significantly reduced with multiple lead SCS from a median of 9.0–6.5 (p < 0.01) and with ITDD from a median of 8.5–5.5 (p < 0.01). There was a trend towards greater reduction in pain in the ITDD group compared with the SCS group (pain differences 4.5 and 2.6, respectively) but this did not reach statistical significance. The majority of psychosocial quality of life measures were significantly more improved in the ITDD group compared with the SCS group (p < 0.05). We conclude that multiple‐lead SCS improves mechanical back pain in patients unresponsive to more conservative measures. However, ITDD provides significantly more improved quality of life measures, with a trend towards greater pain reduction than SCS.

Stability and Analgesic Efficacy of Di-acetyl Morphine (Diamorphine) Compared with Morphine in Implanted Intrathecal Pumps In Vivo.

The objective of this study was to investigate di‐acetyl morphine as an alternative opioid analgesic for use in implanted intrathecal drug delivery systems because of its greater solubility through evaluation of its stability in vivo and analgesic efficacy in the period between pump refills. Contents of intrathecal drug delivery system reservoirs (SynchroMed, Medtronic, Inc., Minneapolis, MN) that had been filled with di‐acetyl morphine dissolved in saline (21), bupivacaine (9), or in both bupivacaine and clonidine (19) were sampled in vivo between 1 and 125 days after refill. The samples were assayed for di‐acetyl morphine and its breakdown products by micellar electrokinetic capillary chromatography. Prospective daily numerical pain scores between pump refills, using 11‐point Likert scales, on 24 patients with implanted SynchroMed pumps (12 delivering di‐acetyl morphine in saline, 12 were delivering morphine in saline) were collected. Results showed that di‐acetyl morphine immediately started to decay to mono‐acetyl morphine in implanted Synchromed pumps with half‐life of 50 days. Mono‐acetyl morphine decayed to morphine with a maxima estimated at 125 days. There was no clinically significant change in average weekly pain scores for up to ten weeks in either group (range, 2.5 to 2.8 for diamorphine and 2.7 to 3.1 for morphine) (2‐way repeated ANOVA, F(9,220) = 0.98, n.s.). We conclude that di‐acetyl morphine and its breakdown products, 6 mono‐acetyl morphine and morphine, provide similar analgesia to morphine alone when administered by intrathecal pump for a period of at least ten weeks and may be a useful alternative when a more soluble agent is favored.