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Pain Physician May 2019Postherpetic neuralgia, a persistent pain condition often characterized by allodynia and hyperalgesia, is a deleterious consequence experienced by patients after an...
BACKGROUND
Postherpetic neuralgia, a persistent pain condition often characterized by allodynia and hyperalgesia, is a deleterious consequence experienced by patients after an acute herpes zoster vesicular eruption has healed. The pain associated with postherpetic neuralgia can severely affect a patient's quality of life, quality of sleep, and ability to participate in activities of daily living. Currently, first-line treatments for this condition include the administration of medication therapies such as tricyclic antidepressants, pregabalin, gabapentin, and lidocaine patches, followed by the application of tramadol and capsaicin creams and patches as second- or third-line therapies. As not all patients respond to such conservative options, however, interventional therapies are valuable for those who continue to experience pain.
OBJECTIVE
This review focuses on interventional therapies that have been subjected to randomized controlled trials for the treatment of postherpetic neuralgia, including transcutaneous electrical nerve stimulation; local botulinum toxin A, cobalamin, and triamcinolone injection; intrathecal methylprednisolone and midazolam injection; stellate ganglion block; dorsal root ganglion destruction; and pulsed radiofrequency therapy.
STUDY DESIGN
Systematic review.
SETTING
Hospital department in Taiwan.
METHODS
Search of PubMed database for all randomized controlled trials regarding postherpetic neuralgia that were published before the end of May 2017.
RESULTS
The current evidence is insufficient for determining the single best interventional treatment. Considering invasiveness, price, and safety, the subcutaneous injection of botulinum toxin A or triamcinolone, transcutaneous electrical nerve stimulation, peripheral nerve stimulation, and stellate ganglion block are recommended first, followed by paravertebral block and pulsed radiofrequency. If severe pain persists, spinal cord stimulation could be considered. Given the destructiveness of dorsal root ganglion and adverse events of intrathecal methylprednisolone injection, these interventions should be carried out with great care and only following comprehensive discussion.
LIMITATIONS
Although few adverse effects were reported, these procedures are invasive, and a careful assessment of the risk-benefit ratio should be conducted prior to administration.
CONCLUSION
With the exception of intrathecal methylprednisolone injection for postherpetic neuralgia, the evidence for most interventional procedures used to treat postherpetic neuralgia is Level 2, according to "The Oxford Levels of Evidence 2". Therefore, these modalities have received only grade B recommendations. Despite the lack of a high level of evidence, spinal cord stimulation and peripheral nerve stimulation are possibly useful for the treatment of postherpetic neuralgia.
KEY WORDS
Interventional treatment, postherpetic neuralgia, botulinum toxin, steroid, stellate ganglion block, peripheral nerve stimulation, paravertebral block, radiofrequency, spinal cord stimulation.
Topics: Female; Humans; Male; Neuralgia, Postherpetic; Pain Management; Randomized Controlled Trials as Topic
PubMed: 31151330
DOI: No ID Found -
Anaesthesia May 2019Opioids are administered peri-operatively for postoperative analgesia, and intra-operatively to control the sympathetic response to surgical stimuli, frequently as a... (Meta-Analysis)
Meta-Analysis
Opioids are administered peri-operatively for postoperative analgesia, and intra-operatively to control the sympathetic response to surgical stimuli, frequently as a surrogate for presumed pain. However, opioid use during surgery is a matter of dispute in contemporary practice and carries the risk of side-effects such as postoperative nausea and vomiting. This meta-analysis investigated whether opioid-inclusive, compared with opioid-free anaesthesia, would reduce postoperative pain, without increasing the rate of postoperative nausea and vomiting. The electronic databases Medline and PubMed were searched until June 2018. We included trials investigating pain outcomes and comparing any type of intra-operative opioid administration with placebo injection or no intra-operative opioid. Most meta-analyses were performed using a random effects model. We rated the quality of evidence for each outcome. The primary outcome was pain score at rest (analogue scale, 0-10) at two postoperative hours. Our secondary outcomes included the rate of postoperative nausea and vomiting within the first 24 postoperative hours and length of stay in the recovery area. Twenty-three randomised controlled trials, including 1304 patients, were identified. Pain scores at rest at two postoperative hours were equivalent in the opioid-inclusive and opioid-free groups with a mean difference (95%CI) of 0.2 (-0.2 to 0.5), I = 83%, p = 0.38 and a high quality of evidence. Similarly, there was high-quality evidence that the rate of postoperative nausea and vomiting was reduced in the opioid-free group, with a risk ratio (95%CI) of 0.77 (0.61-0.97), I = 16%, p = 0.03 and high-quality evidence for a similar length of stay in the recovery area, the mean difference (95%CI) being 0.6 (-8.2 to 9.3), min, I = 60%, p = 0.90. As there is strong evidence that opioid-inclusive anaesthesia does not reduce postoperative pain, but is associated with more postoperative nausea and vomiting, when compared with opioid-free anaesthesia, we suggest that anaesthetists should reconsider their intra-operative opioid choices on a case-by-case basis.
Topics: Analgesics, Opioid; Anesthesia, General; Drug Administration Schedule; Humans; Intraoperative Care; Pain, Postoperative; Postoperative Nausea and Vomiting
PubMed: 30802933
DOI: 10.1111/anae.14582 -
Journal of Cutaneous and Aesthetic... 2020Post-herpetic neuralgia (PHN) is usually a constant or intermittent burning, stabbing, or sharp shooting pain with hyperalgesia or allodynia, persisting beyond the... (Review)
Review
BACKGROUND
Post-herpetic neuralgia (PHN) is usually a constant or intermittent burning, stabbing, or sharp shooting pain with hyperalgesia or allodynia, persisting beyond the healing of herpetic skin lesions. This review was carried out in concordance to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We used PICOS (Population, Intervention, Control, and Outcome Study) design for inclusion of potential studies into this review. Online literature available in PubMed, Cochrane, and Embase was searched for studies from January 1995 till March 2020, which evaluated interventional treatments in PHN by an independent reviewer, using the relevant medical subject heading (MeSH) terms. We analyzed the following outcome parameters with regard to each intervention-pain status at predefined fixed intervals after the intervention, quality of sleep using any of the reported questionnaires, analgesic consumption, functional evaluation, and quality of life assessment after the intervention.
CONCLUSION
Interventional pain management options provide effective and long-lasting pain relief to patients not responding to medical management. The choice of intervention will depend on the region involved, cost, and invasiveness. Simple procedures such as intercostal nerve blocks/neurolysis, stellate ganglion blocks, paravertebral neurolysis, epidural steroid injections, and dorsal root ganglion-radiofrequency ablation are effective interventions, and if they fail, spinal cord stimulators could be effective in the hands of experienced pain physicians.
PubMed: 33911406
DOI: 10.4103/JCAS.JCAS_45_20 -
British Journal of Anaesthesia Jun 2014Opioids can increase sensitivity to noxious stimuli and cause opioid-induced hyperalgesia. We performed a systematic review to evaluate the clinical consequences of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Opioids can increase sensitivity to noxious stimuli and cause opioid-induced hyperalgesia. We performed a systematic review to evaluate the clinical consequences of intra-operative doses of opioid.
METHODS
We identified randomized controlled trials which compared intra-operative opioid to lower doses or placebo in adult patients undergoing surgery from MEDLINE, EMBASE, LILAC, Cochrane, and hand searches of trial registries. We pooled data of postoperative pain intensity, morphine consumption, incidence of opioid-related side-effects, primary and secondary hyperalgesia. For dichotomous outcomes relative risks [95% confidence intervals (CIs)] and for continuous outcomes mean differences (MDs) or standardized mean difference (SMD; 95% CI) were calculated.
RESULTS
Twenty-seven studies involving 1494 patients were included in the analysis. Patients treated with high intra-operative doses of opioid reported higher postoperative pain intensity than the reference groups (MD: 9.4 cm; 95% CI: 4.4, 14.5) at 1 h, (MD: 7.1 cm; 95% CI: 2.8, 11.3) at 4 h, and (MD: 3 cm; 95% CI: 0.4, 5.6) at 24 h on a 100 cm visual analogue scale. They also showed higher postoperative morphine use after 24 h (SMD: 0.7; 95% CI: 0.37, 1.02). There was no difference in the incidences of nausea, vomiting, and drowsiness. These results were mainly associated with the use of remifentanil. The impact of other opioids is less clear because of limited data.
DISCUSSION
This review suggests that high intra-operative doses of remifentanil are associated with small but significant increases in acute pain after surgery.
Topics: Analgesics, Opioid; Dose-Response Relationship, Drug; Humans; Hyperalgesia; Pain Measurement; Pain, Postoperative; Piperidines; Randomized Controlled Trials as Topic; Remifentanil
PubMed: 24829420
DOI: 10.1093/bja/aeu137 -
The Cochrane Database of Systematic... Dec 2018Inadequate pain management after surgery increases the risk of postoperative complications and may predispose for chronic postsurgical pain. Perioperative ketamine may... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Inadequate pain management after surgery increases the risk of postoperative complications and may predispose for chronic postsurgical pain. Perioperative ketamine may enhance conventional analgesics in the acute postoperative setting.
OBJECTIVES
To evaluate the efficacy and safety of perioperative intravenous ketamine in adult patients when used for the treatment or prevention of acute pain following general anaesthesia.
SEARCH METHODS
We searched CENTRAL, MEDLINE and Embase to July 2018 and three trials registers (metaRegister of controlled trials, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP)) together with reference checking, citation searching and contact with study authors to identify additional studies.
SELECTION CRITERIA
We sought randomised, double-blind, controlled trials of adults undergoing surgery under general anaesthesia and being treated with perioperative intravenous ketamine. Studies compared ketamine with placebo, or compared ketamine plus a basic analgesic, such as morphine or non-steroidal anti-inflammatory drug (NSAID), with a basic analgesic alone.
DATA COLLECTION AND ANALYSIS
Two review authors searched for studies, extracted efficacy and adverse event data, examined issues of study quality and potential bias, and performed analyses. Primary outcomes were opioid consumption and pain intensity at rest and during movement at 24 and 48 hours postoperatively. Secondary outcomes were time to first analgesic request, assessment of postoperative hyperalgesia, central nervous system (CNS) adverse effects, and postoperative nausea and vomiting. We assessed the evidence using GRADE and created a 'Summary of findings' table.
MAIN RESULTS
We included 130 studies with 8341 participants. Ketamine was given to 4588 participants and 3753 participants served as controls. Types of surgery included ear, nose or throat surgery, wisdom tooth extraction, thoracotomy, lumbar fusion surgery, microdiscectomy, hip joint replacement surgery, knee joint replacement surgery, anterior cruciate ligament repair, knee arthroscopy, mastectomy, haemorrhoidectomy, abdominal surgery, radical prostatectomy, thyroid surgery, elective caesarean section, and laparoscopic surgery. Racemic ketamine bolus doses were predominantly 0.25 mg to 1 mg, and infusions 2 to 5 µg/kg/minute; 10 studies used only S-ketamine and one only R-ketamine. Risk of bias was generally low or uncertain, except for study size; most had fewer than 50 participants per treatment arm, resulting in high heterogeneity, as expected, for most analyses. We did not stratify the main analysis by type of surgery or any other factor, such as dose or timing of ketamine administration, and used a non-stratified analysis.Perioperative intravenous ketamine reduced postoperative opioid consumption over 24 hours by 8 mg morphine equivalents (95% CI 6 to 9; 19% from 42 mg consumed by participants given placebo, moderate-quality evidence; 65 studies, 4004 participants). Over 48 hours, opioid consumption was 13 mg lower (95% CI 10 to 15; 19% from 67 mg with placebo, moderate-quality evidence; 37 studies, 2449 participants).Perioperative intravenous ketamine reduced pain at rest at 24 hours by 5/100 mm on a visual analogue scale (95% CI 4 to 7; 19% lower from 26/100 mm with placebo, high-quality evidence; 82 studies, 5004 participants), and at 48 hours by 5/100 mm (95% CI 3 to 7; 22% lower from 23/100 mm, high-quality evidence; 49 studies, 2962 participants). Pain during movement was reduced at 24 hours (6/100 mm, 14% lower from 42/100 mm, moderate-quality evidence; 29 studies, 1806 participants), and 48 hours (6/100 mm, 16% lower from 37 mm, low-quality evidence; 23 studies, 1353 participants).Results for primary outcomes were consistent when analysed by pain at rest or on movement, operation type, and timing of administration, or sensitivity to study size and pain intensity. No analysis by dose was possible. There was no difference when nitrous oxide was used. We downgraded the quality of the evidence once if numbers of participants were large but small-study effects were present, or twice if numbers were small and small-study effects likely but testing not possible.Ketamine increased the time for the first postoperative analgesic request by 54 minutes (95% CI 37 to 71 minutes), from a mean of 39 minutes with placebo (moderate-quality evidence; 31 studies, 1678 participants). Ketamine reduced the area of postoperative hyperalgesia by 7 cm² (95% CI -11.9 to -2.2), compared with placebo (very low-quality evidence; 7 studies 333 participants). We downgraded the quality of evidence because of small-study effects or because the number of participants was below 400.CNS adverse events occurred in 52 studies, while 53 studies reported of absence of CNS adverse events. Overall, 187/3614 (5%) participants receiving ketamine and 122/2924 (4%) receiving control treatment experienced an adverse event (RR 1.2, 95% CI 0.95 to 1.4; high-quality evidence; 105 studies, 6538 participants). Ketamine reduced postoperative nausea and vomiting from 27% with placebo to 23% with ketamine (RR 0.88, 95% CI 0.81 to 0.96; the number needed to treat to prevent one episode of postoperative nausea and vomiting with perioperative intravenous ketamine administration was 24 (95% CI 16 to 54; high-quality evidence; 95 studies, 5965 participants).
AUTHORS' CONCLUSIONS
Perioperative intravenous ketamine probably reduces postoperative analgesic consumption and pain intensity. Results were consistent in different operation types or timing of ketamine administration, with larger and smaller studies, and by higher and lower pain intensity. CNS adverse events were little different with ketamine or control. Perioperative intravenous ketamine probably reduces postoperative nausea and vomiting by a small extent, of arguable clinical relevance.
Topics: Acute Pain; Adult; Analgesics; Analgesics, Opioid; Central Nervous System Diseases; Humans; Hyperalgesia; Injections, Intravenous; Ketamine; Morphine; Pain Measurement; Pain, Postoperative; Postoperative Nausea and Vomiting; Randomized Controlled Trials as Topic
PubMed: 30570761
DOI: 10.1002/14651858.CD012033.pub4 -
The Journal of Pain Aug 2019Learning processes have been discussed in the context of pain chronicity for decades. Particularly, operant conditioning has been used to experimentally induce and... (Meta-Analysis)
Meta-Analysis
Learning processes have been discussed in the context of pain chronicity for decades. Particularly, operant conditioning has been used to experimentally induce and modulate pain in healthy humans. In this systematic review and meta-analysis, research findings on pain facilitation (hyperalgesic effect) and pain elicitation (allodynic effect) are evaluated. The review was performed according to the PRISMA guideline and an a priori published protocol. Nine databases were searched for relevant publications: PubMed, Cochrane Register of Controlled Trials (CENTRAL), Web of Science, ScienceDirect, EBSCO, PsycINFO, MEDLINE, PsycARTICLES, and CINAHL. Studies were included if they investigated pain-free humans, exposed to an operant conditioning procedure of pain. Two independent assessors screened publications against eligibility criteria and assessed the risk of bias with the Cochrane risk of bias scale. A total of 3155 records were screened, of which 8 were included in the qualitative (401 participants) and 5 into the quantitative (110 participants) synthesis. Results showed that hyperalgesic (standardized mean difference = -0.80, 95% confidence interval = -1.33 to -0.27, P = .003) and allodynic effects (standardized mean difference = -1.27, 95% confidence interval = -2.46 to -0.08, P = .04) can be induced in healthy humans, indicating that pain can be shaped by contingencies of reinforcement. However, the uncertainty of the effect is relatively high, mostly owing to the small number of included studies, demand characteristics, and the risk of bias. This is especially relevant for studies on allodynic effects where the decrease in nociception should be more rigorously controlled. PERSPECTIVE: Operant conditioning can be a mechanism of pain chronicity. All experimental studies investigating this hypothesis have been identified and summarized. It has been demonstrated that allodynic and hyperalgesic effects can be induced by operant conditioning.
Topics: Chronic Pain; Conditioning, Operant; Humans; Hyperalgesia; Randomized Controlled Trials as Topic; Reinforcement, Psychology
PubMed: 30690165
DOI: 10.1016/j.jpain.2019.01.009 -
Brazilian Oral Research 2015A systematic review was conducted to identify reliable somatosensory evaluation methods for atypical odontalgia (AO) patients. The computerized search included the main... (Review)
Review
A systematic review was conducted to identify reliable somatosensory evaluation methods for atypical odontalgia (AO) patients. The computerized search included the main databases (MEDLINE, EMBASE, and Cochrane Library). The studies included used the following quantitative sensory testing (QST) methods: mechanical detection threshold (MDT), mechanical pain threshold (MPT) (pinprick), pressure pain threshold (PPT), dynamic mechanical allodynia with a cotton swab (DMA1) or a brush (DMA2), warm detection threshold (WDT), cold detection threshold (CDT), heat pain threshold (HPT), cold pain detection (CPT), and/or wind-up ratio (WUR). The publications meeting the inclusion criteria revealed that only mechanical allodynia tests (DMA1, DMA2, and WUR) were significantly higher and pain threshold tests to heat stimulation (HPT) were significantly lower in the affected side, compared with the contralateral side, in AO patients; however, for MDT, MPT, PPT, CDT, and WDT, the results were not significant. These data support the presence of central sensitization features, such as allodynia and temporal summation. In contrast, considerable inconsistencies between studies were found when AO patients were compared with healthy subjects. In clinical settings, the most reliable evaluation method for AO in patients with persistent idiopathic facial pain would be intraindividual assessments using HPT or mechanical allodynia tests.
Topics: Adult; Facial Pain; Female; Humans; Male; Middle Aged; Pain Measurement; Pain Threshold; Physical Stimulation; Randomized Controlled Trials as Topic; Toothache
PubMed: 25627886
DOI: 10.1590/1807-3107BOR-2015.vol29.0020 -
Antioxidants (Basel, Switzerland) Nov 2022The control of neuropathic pain is a leading challenge in modern medicine. Traditional medicine has, for a long time, used natural compounds such as nutraceuticals for... (Review)
Review
The control of neuropathic pain is a leading challenge in modern medicine. Traditional medicine has, for a long time, used natural compounds such as nutraceuticals for this purpose, and extensive evidence has supported their role in controlling oxidative stress and persistent pain-related inflammation. Nutraceuticals are natural products belonging to the food sector whose consumption could be related to physiological benefits. Indeed, they are used to improve health, prevent chronic diseases, and delay the aging process. Here, we report a systematic review and meta-analysis to provide a more comprehensive report on the use of nutraceuticals in neuropathic pain, including evaluating confounding factors. A search of the literature has been conducted on principal databases (PubMed, MEDLINE, EMBASE, and Web of Science) following the PRISMA statement, and we retrieved 484 articles, 12 of which were selected for the meta-analysis. The results showed that administration of natural drugs in animals with neuropathic pain led to a significant reduction in thermal hyperalgesia, measured in both the injured paw (SMD: 1.79; 95% CI: 1.41 to 2.17; p < 0.0001) and in the two paws (SMD: −1.74; 95% CI: −3.36 to −0.11; p = 0.036), as well as a reduction in mechanical allodynia and hyperalgesia (SMD: 1.95, 95% CI: 1.08 to 2.82; p < 0.001) when compared to controls. The results of the review indicate that nutraceutical compounds could be clinically relevant for managing persistent neuropathic pain.
PubMed: 36552569
DOI: 10.3390/antiox11122361 -
Journal of Pain Research 2023To assess the inhibitory effect of acupuncture on pain symptoms in migraine models, and to further summarize the potential mechanisms of acupuncture in regulating... (Review)
Review
PURPOSE
To assess the inhibitory effect of acupuncture on pain symptoms in migraine models, and to further summarize the potential mechanisms of acupuncture in regulating hyperalgesia in the treatment of migraine.
MATERIALS AND METHODS
Literature search in databases such as China National Knowledge Infrastructure (CNKI), PubMed, and Web of Science (WOS) etc. The quality was evaluated by the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) bias risk assessment tool and Collaborative Approach to Meta-analysis and Review of Animal Data from Experimental Studies (CAMARADES) checklist. Meta-analyses were performed using Stata 17.0 software.
RESULTS
Twenty-one studies involving 489 animals were identified. The qualitative score ranged from 3 to 9 points. Facial mechanical withdrawal threshold (FMWT) and paw mechanical withdrawal threshold (PMWT) measured by Von Frey filaments were selected as major outcomes, and serum calcitonin gene-related peptide (CGRP) levels measured by ELISA were selected as secondary outcome. Meta-analysis results revealed that true acupuncture (TA) group significantly increased FMWT, PMWT and CGRP compared to model group. TA group showed superior effect in FMWT, PMWT relative to sham acupuncture (SA) group. Subgroup analysis results showed that high risk of bias scores may be responsible for the high heterogeneity of FMWT; additionally, CGRP analysis suggests that acupoint selection and blood collection sites may be sources of heterogeneity. In the treatment of migraine pain symptoms, the underlying mechanism of acupuncture treatment is either the regulation of hyperalgesia and neurotransmitters, or the reduction of inflammatory factors.
CONCLUSION
The results indicate that TA treatment effectively increased the pain threshold and reduced hyperalgesia in migraine rats. In summary, our study highlights the potential of TA as an effective treatment for migraine, but further investigation is required to fully comprehend its mechanism of action and optimize its clinical application.
PubMed: 37521010
DOI: 10.2147/JPR.S422050 -
Frontiers in Neurology 2022The role of GABAergic cell transplantation in improving neuropathic pain is controversial. We comprehensively searched the relevant literature to identify animal studies...
The role of GABAergic cell transplantation in improving neuropathic pain is controversial. We comprehensively searched the relevant literature to identify animal studies of GABAergic cell transplantation that recorded pain behaviors as an outcome according to the Cochrane Handbook 5.0.2. Controlled studies assessing the administration of GABAergic neurons or GABAergic neuronal progenitor cells to rat or mouse neuropathic pain animal models were included. Basic design information and mechanical allodynia thresholds and heat hyperalgesia thresholds data were collected. The risk of bias for the animal experiments was assessed according to the SYRCLE's tool. This study included 10 full-text articles. GABAergic cells transplantation leads to a statistically significant improvement of allodynia (SMD = 5.26; 95% confidence interval: 3.02-7.51; < 0.001) and hyperalgesia (SMD: 4.10; 95% confidence interval: 1.84-6.35; < 0.001). Differentiated GABAergic cells and without antibiotics using may have a better effect for improving neuropathic pain. GABAergic cell transplantation is a promising treatment for improving neuropathic pain. This systematic review and meta-analysis evaluated the effects of GABAergic cell transplantation on neuropathic pain, which can guide future clinical trials and possible clinical treatments, and better attenuate neuropathic pain caused by abnormal circuit hyperexcitability.
PubMed: 35860495
DOI: 10.3389/fneur.2022.900436