Ketamine in chronic pain: A Delphi survey.

BACKGROUND: There is no recommendation in Europe for the use of ketamine in patients with chronic pain. The heterogeneity of practice highlights the need to seek the advice of experts in order to establish a national consensus. This Delphi survey aimed to reach a national consensus on the use of ketamine in chronic pain in Pain clinics. METHODS: A collaborative four-round internet-based questionnaire was used. It was created after literature search on ketamine administration in chronic pain and included about 96 items. It discussed utility and advantages, adverse events and deleterious aspects, methods of administration, concomitant treatments and assessment of results. RESULTS: Twenty-eight experts completed all rounds of the survey with a total of 81.3% items reaching a consensual answer. Neuropathic pain represents the first indication to use ketamine, followed, with a good to moderate utility, by other situations (fibromyalgia, complex regional pain syndrome, central neuropathic pain, peripheral neuropathic pain, nociceptive pain, sensitization, opioid withdrawal, palliative care, depression). Experts agreed on the rare occurrence of adverse events. Concerning routes of administration, intravenous infusion with doses of 0.5-0.9 mg/kg/d for 4 days of treatment is preferred. Place of care is hospital, as in- or out-patient, with a quarterly administration of ketamine. Finally, ketamine effectiveness is assessed 1 month after infusion, and experts encourage combination with non-pharmacological treatment. CONCLUSIONS: This Delphi survey established a consensus of pain specialists on the use of ketamine in refractory chronic pain, thus providing a basis for future comparative trials. SIGNIFICANCE: This Delphi survey in chronic pain reached agreement on four main aspects: (1) Priority to treat neuropathic pain with evaluation of effectiveness at 1 month; (2) No deleterious effects in the majority of listed diseases/situations with the absence or <3% of suggested adverse events; (3) 0.5-0.9 mg/kg/d IV infusion; (4) Combination with non-pharmacological treatment.

Recommendations on the management of pudendal nerve entrapment syndrome: A formalised expert consensus.

BACKGROUND: Since the development and publication of diagnostic criteria for pudendal nerve entrapment (PNE) syndrome in 2008, no comprehensive work has been published on the clinical knowledge in the management of this condition. The aim of this work was to develop recommendations on the diagnosis and the management of PNE. METHODS: The methodology of this study was based on French High Authority for Health Method for the development of good practice and the literature review was based on the PRISMA method. The selected articles have all been evaluated according to the American Society of Interventional Pain Physicians assessment grid. RESULTS: The results of the literature review and expert consensus are incorporated into 10 sections to describe diagnosis and management of PNE: (1) diagnosis of PNE, (2) patients advice and precautions, (3) drugs treatments, (4) physiotherapy, (5) transcutaneous electrostimulations (TENS), (6) psychotherapy, (7) injections, (8) surgery, (9) pulsed radiofrequency, and (10) Neuromodulation. The following major points should be noted: (i) the relevance of 4+1 Nantes criteria for diagnosis; (ii) the preference for initial monotherapy with tri-tetracyclics or gabapentinoids; (iii) the lack of effect of opiates, (iv) the likely relevance (pending more controlled studies) of physiotherapy, TENS and cognitive behavioural therapy; (v) the incertitudes (lack of data) regarding corticoid injections, (vi) surgery is a long term effective treatment and (vii) radiofrequency needs a longer follow-up to be currently proposed in this indication. CONCLUSION: These recommendations should allow rational and homogeneous management of patients suffering from PNE. They should also allow to shorten the delays of management by directing the primary care. SIGNIFICANCE: Pudendal nerve entrapment (PNE) has only been known for about 20 years and its management is heterogeneous from one practitioner to another. This work offers a synthesis of the literature and international experts' opinions on the diagnosis and management of PNE.

Spinal cord stimulation of the conus medullaris for refractory pudendal neuralgia: a prospective study of 27 consecutive cases.

AIMS: Thirty percent of patients with pudendal neuralgia due to pudendal nerve entrapment obtain little or no relief from nerve decompression surgery. The objective was to describe the efficacy of spinal cord stimulation of the conus medullaris in patients with refractory pudendal neuralgia. METHODS: This prospective study, conducted by two centers in the same university city, described the results obtained on perineal pain and functional disability in all patients with an implanted conus medullaris stimulation electrode for the treatment of refractory pudendal neuralgia. Twenty-seven consecutive patients were included by a multidisciplinary pelvis and perineal pain clinic between May 2011 and July 2012. Mean follow-up was 15 months. The intervention was an insertion of a stimulation electrode was followed by a test period (lasting an average of 13 days) before deciding on permanent electrode implantation. Maximum and average perineal pain scores and the pain-free sitting time were initially compared during the test and in the long-term (paired t-test). The estimated percent improvement (EPI) was evaluated in the long-term. RESULTS: Twenty of the 27 patients were considered to be responders to spinal cord stimulation and 100% of implanted patients remained long-term responders (mean tripling of sitting time, and mean EPI of 55.5%). CONCLUSIONS: Spinal cord stimulation of the conus medullaris is a safe and effective technique for long-term treatment of refractory pudendal neuralgia. Routine use of this technique, which has never been previously reported in the literature in this type of patient, must now be validated by a larger scale study.

5% lidocaine medicated plaster in elderly patients with postherpetic neuralgia: results of a compassionate use programme in France.

BACKGROUND: Postherpetic neuralgia (PHN) is a common, debilitating complication of herpes zoster that has a major impact on patients' quality of life. PHN prevalence increases with advancing age. One treatment option is the topical analgesic 5% lidocaine (lignocaine) medicated plaster (Versatis®), which has been proven to be efficacious and well tolerated in a number of randomized clinical studies. OBJECTIVE: The aim of this analysis was to assess the use of the lidocaine medicated plaster under clinical practice conditions in a patient population whose previous PHN treatment with antidepressant and/or antiepileptic agents was inadequate or was not tolerated, or for whom such treatment was contraindicated or not recommended. METHODS: This was a prospective, multicentre, non-interventional observation conducted in private and public health centres in France under a compassionate use programme (CUP). To obtain this new - and, at the time, unauthorized - PHN treatment alternative, physicians (in accordance with French guidelines) had to complete standardized case report forms for each patient before his/her inclusion in the CUP. As it was a CUP and therefore a non-interventional observation, returning documented information on follow-up visits to the medication provider was voluntary, and only a limited number of physicians returned completed forms. Documentation was, however, mandatory for adverse events (AEs) occurrence. Depending on the size of the painful skin area, up to three lidocaine plasters daily were applied for a maximum of 12 hours with plaster-free intervals of at least 12 hours. The study assessed changes in the prescription of concomitant PHN medication from the start of lidocaine plaster treatment to the last follow-up visit, both in terms of the sum of all concomitant PHN treatments and stratified by type of treatment: antiepileptic drugs, tricyclic antidepressants (TCAs), serotonin reuptake inhibitors (SRIs), classical analgesics (classified as step 1, 2 or 3 according to the WHO cancer pain ladder), transcutaneous electrical nerve stimulation, and others (mainly NSAIDs). AEs were monitored for safety. RESULTS: A total of 625 patients were included in the CUP and permitted to receive lidocaine plaster treatment. Physicians returned 273 documented follow-up visit report forms. The mean ± SD CUP duration (i.e. duration of lidocaine plaster treatment) was 2.4 ± 2.5 months (median 1 month). Efficacy was assessed in the group of patients with documented follow-up visits (n = 273; mean ± SD age 73.6 ± 11.2 years), of whom 184 were aged ≥70 years (elderly efficacy population). The safety analysis included 625 patients (mean ± SD age 73.2 ± 11.9 years). Lidocaine plaster treatment resulted in a significant mean reduction of one concomitant PHN treatment per patient in the overall efficacy population analysed at the end of the observation (p < 0.001). In both populations (overall efficacy and elderly efficacy population), significantly fewer patients received TCAs (p = 0.003 and p = 0.001, respectively), step 3 analgesics (p = 0.001 and p = 0.005, respectively), and other miscellaneous treatments (p < 0.001 for both populations); there was also a significant reduction in the proportion of patients who took step 2 analgesics (p = 0.009) in the overall efficacy group. AEs (mainly related to local plaster application) were documented for 2.6% of the patients in the safety population; none were considered serious. CONCLUSIONS: In day-to-day clinical practice management of PHN, treatment with the 5% lidocaine medicated plaster permitted a significant quantitative reduction in concomitant treatments for neuropathic pain in the overall efficacy population. In the subgroup aged ≥70 years, the quantitative reduction was non-significant. However, in both populations, 5% lidocaine medicated plaster reduced use of TCAs and step 3 analgesics. An improved polymedication status and good tolerability in this likely multimorbid age group indicate that the plaster is a new therapeutic alternative for patients suffering from PHN in France.