Risk Factors and a Nomogram for Prediction of Refractory Pudendal Neuralgia: A Retrospective Multivariate Analysis Study.

BACKGROUND: Pudendal neuralgia (PN) is one of the most common forms of genital pain. About 4% or higher of patients suffering from chronic pain. OBJECTIVES: The aim of this study was to evaluate the risk factors for prediction of refractory PN (RPN). STUDY DESIGN: A retrospective multivariate analysis study. SETTING: This retrospective analysis included 112 patients with PN who received the pudendal nerve block treatment at the Pain Department of General Hospital of People's Liberation Army. METHODS: Univariate and multivariable logistic regression analyses were used for covariates selection. A nomogram was developed to estimate nonresponse to the pudendal nerve block. RESULTS: The median age of patients and duration of patients were 48.0 and 1.25 years, respectively. Among 112 patients, there were 64 good responders to the pudendal nerve block for neuropathic pain and 48 nonresponders. Multivariate analysis of 112 patients with PN demonstrated high self-rating depression scale scores (> 32) (odds ratio [OR], 95% confidence interval [CI]: 0.11, 0.01-0.77), damage to more than 2 terminal branches (OR, 95% CI: 0.22, 0.07-0.71), sensory deficit at S2-S4 on the dermatome map (OR, 95% CI: 0.22, 0.05-0.90), and duration of pain (> 4 years) (OR, 95% CI: 0.10, 0.03-0.42) were significant prognostic factors for nonresponse to the pudendal nerve block. LIMITATIONS: There are information biases for retrospective analysis, thus making it more difficult to come up with definitive conclusions. Large-scale randomized clinical trials are warranted to evaluate the risk factors for prediction of RPN. CONCLUSIONS: A longer duration of pain was correlated with a worse prognosis of the neurological disease. Patients with depression were prone to nonresponse to the pudendal nerve block treatment. Pain involved in more than 2 terminal branches and small fibers, affected at S2-S4 dermatome map, were considered to poor prognosis.

Sacral Nerve Stimulation in Patients With Refractory Pudendal Neuralgia.

BACKGROUND: Pudendal neuralgia (PN) is one of the most common forms of genital pain. Only 42.2% of PN patients respond to the first-line treatment. Novel neuromodulation techniques in the treatment of refractory PN patients are urgently required. OBJECTIVES: The aim of this study was to evaluate the treatment effects and adverse events of sacral nerve stimulation (SNS) for patients with refractory PN. STUDY DESIGN: A prospective nonrandomized study. SETTING: This prospective analysis included 33 patients who received the phase II surgical implantation. METHODS: A total of 55 eligible PN patients were recruited for SNS treatment after informed consent, and 33 of 55 patients with a minimum 50% improvement were candidates for surgical implantation. Visual Analog Scale (VAS) scores, Self-rating Anxiety and Depression Scale, Quality of life score (SF-36), and sleep monitoring indicators before and after surgery were used to assess the effects of SNS on patients with refractory PN. RESULTS: Thirty-three patients were included in the final analysis, involving 24 women and 9 men with a mean age of 49.5 years (26-70 years). There was a favorable decrease in pain severity (VAS scores) from 7.1 ± 1.1 at baseline to 6.1 ± 1.0 on postoperative day 1, and 2.8 ± 0.7 at 1 week, 1.7 ± 0.5 at 1 month, 1.1 ± 0.7 at 6 months, and 1.0 ± 0.6 at 12 months after surgery, respectively (P < 0.05). The mean score of each section of SF-36 after SNS was significantly higher than that at baseline (P < 0.05). Total sleep time and sleep time in each period were significantly prolonged after SNS implantation compared with that before surgery (6 months vs Pre, total: 5.32 ± 1.49 hours vs 3.66 ± 1.19 hours, deep: 2.52 ± 0.63 hours vs 1.36 ± 0.43 hours, light: 1.78 ± 0.42 hours vs 0.99 ± 0.30 hours, rapid eye movement: 1.41 ± 0.29 hours vs 0.89 ± 0.27 hours, P < 0.05). No serious device complications were reported during the follow-up period. LIMITATIONS: Large-scale randomized clinical trials are warranted to evaluate the risk factors for prediction of refractory PN. CONCLUSIONS: These data imply that SNS can have beneficial effects on patients with refractory PN.

Programmable Pump for Intrathecal Morphine Delivery to Cisterna Magna: Clinical Implications in Novel Management of Refractory Pain Above Middle Thoracic Vertebrae Level Utilizing a Prospective Trial Protocol and Review.

BACKGROUND: The cisterna Intrathecal Drug Delivery system (IDDS) with morphine has proven to be effective in treating refractory cancer pain above the middle thoracic vertebrae level in some countries. However, it has not been fully investigated in others. We designed the current project to investigate the efficacy and safety of cisterna IDDS for pain relief in refractory pain above the middle thoracic vertebrae level in advanced cancer patients. METHODS: This study protocol allows for eligible cancer patients to receive the cisterna IDDS operation. Pain intensity (Visual Analogue scale, VAS), quality of life (36-Item Short-Form Health Survey, SF-36), and depression (Self-Rating Depression scale, SDS) are assessed along with side effects in the postoperative follow-up visits. Recent literature suggests a potential role for cisterna IDDS morphine delivery for refractory pain states above the middle thoracic level. CONCLUSION: The results of this study may provide further evidence that cisterna IDDS of morphine can serve as an effective and safe pain relief strategy for refractory pain above the middle thoracic vertebrae level in advanced cancer patients.

Efficacy of repetitive paravertebral block combined with medication in the treatment of zoster-related pain with different courses.

OBJECTIVES: To compare the clinical outcomes of repetitive paravertebral block (PVB) combining oral medication in the treatment of zoster-related pain (ZP) with different courses. METHODS: Sixty-seven patients with ZP were divided into 3 groups based on their course of herpes zoster (HZ). Group I: 24 patients with acute herpetic neuralgia (within one month of disease onset); group II: 22 patients with subacute herpetic neuralgia (disease onset from 1 to 3 months); group III: 21 patients with postherpetic neuralgia (more than 3 months since disease onset). All patients received ultrasound-guided repetitive PVB with oral gabapentin and tramadol sustained-release tablets. The VAS and QS scores and the incidences of hematoma, dizziness, nausea, and drowsiness were compared at 1 day, 3 months, and 6 months after treatment. RESULTS: Pain intensity and sleep quality of the 3 groups improved to varying degrees after treatment. The best efficacy was achieved in the acute group, followed by the subacute group, and the poorest efficacy was observed in the chronic group. CONCLUSION: The efficacy of ultrasound-guided repetitive PVB with oral medication varied with the courses of HZ. The shorter the time since onset, the better the efficacy. This combined treatment showed better efficacy in patients at the acute and subacute stages and significantly improved their pain and sleep quality, while demonstrating limited pain relief in chronic patients.

Intrathecal Morphine Delivery at Cisterna Magna to Control Refractory Cancer-Related Pain: A Prospective Cohort Study.

Background: For patients suffering from primary or metastatic cancer above the middle thoracic vertebrae, refractory pain management still remains a great challenge. Theoretically, inserting a catheter tip into the cisterna magna may be a promising solution. However, at present, there have been no reliable data regarding this novel technique. We therefore investigated the efficacy and safety of an advanced approach for pain relief in a specific population. Methods: Thirty participants from two hospitals received the intrathecal deliveries of opioid to either one of two sites: cisterna magna (n = 15) or lower thoracic region (n = 15). Pain relief (visual analogue scale, VAS), quality of life (short form (36) health survey, SF-36) as well as depression (self-rating depression scale, SDS) were assessed in the follow-up visits and compared between the two groups. Results: Patients receiving intrathecal morphine delivery to cisterna magna achieved greater pain improvement indicated as significant decrease of VAS scores at day 1 and 7, and achieved better improvement in physical function (day 7 and 30), role physical (day 7 and 30), body pain (day 7, 30 and 90), general health (day 7, 30 and 90), vitality (day 7, 30 and 90), social function (day 90), role emotional (day 7 and 90), mental health (day 7, 30 and 90) and SDS (day 1 and 7). Conclusions: Intrathecal morphine delivery to cisterna magna might be an effective and safe technique for patients suffering from cancer at the middle thoracic vertebrae or above to control refractory pain. Trial registration: No. ChiCTR-ONN-17010681.

Correction to: Comparison of analgesic effect of oxycodone and morphine on patients with moderate and advanced cancer pain: a meta-analysis.

After publication of this article [1], the authors noted that the corresponding email address is incorrect.

Comparison of analgesic effect of oxycodone and morphine on patients with moderate and advanced cancer pain: a meta-analysis.

BACKGROUND: Morphine and oxycodone are considered as wide-spreadly used opioids for moderate/severe cancer pain. However, debate exists about the evidence regarding their relative tolerability and underlying results. METHODS: A systematic search of online electronic databases, including PubMed, Embase, Cochrane library updated on October 2017 were conducted. The meta-analysis was performed including the studies that were designed as randomized controlled trials. RESULTS: In total, seven randomized clinical trials met our inclusion criteria. No statistical differences in analgesic effect between oxycodone and morphine were observed. Both the pooled analysis of API (MD =0.01, 95% CI -0.22 - 0.23; p = 0.96) and WPI (MD = - 0.05, 95% CI -0.21 - 0.30; p = 0.72) demonstrated clinical non-inferiority of the efficacy of morphine compared with oxycodone, respectively. Additionally, no significant difference in PRR response was observed in either oxycodone or morphine that were used in patients (MD =0.99, 95% CI -0.88 - 1.11; p = 0.87). With the pooled result of AEs indicating the comparable safety profiles between the 2 treatment groups, the meta-analysis on the nausea (OR = 1.20, 95% CI 0.90-1.59; p = 0.22), vomiting (OR = 1.33, 95% CI 0.75-2.38; p = 0.33), somnolence (OR = 1.35, 95% CI 0.95-1.93; p = 0.10), diarrhea (OR = 1.01, 95% CI 0.60-1,67; p = 0.98), and constipation (OR = 1.04, 95% CI 0.77-1.41; p = 0.79) was conducted, respectively. CONCLUSIONS: In the current study, no remarkable difference was identified either in analgesic efficacy or in tolerability of oxycodone and morphine as the first-line therapy for patients with moderate to severe cancer pain. Thus, no sufficient clinical evidence on the superior effects of oxycodone to morphine was provided in this experimental hypothesis.

The analgesia effect of duloxetine on post-operative pain via intrathecal or intraperitoneal administration.

One promising strategy to prevent the chronicity of post-operative pain (POP) is to attenuate acute POP during the early phase by efficacious medications with fewer side effects. Duloxetine, one of the serotonin (5-HT)-norepinephrine (NE) reuptake inhibitors (SNRI), is used to treat a wide range of acute and chronic pain. However, its effect on POP has not been investigated. In the present study, we investigated the anti-hypersensitivity effect of duloxetine using a rat model of POP. The possible involvement of spinal 5-HT2A and α2-noradrenergic receptors were also evaluated by using antagonists for 5-HT2A (ketanserin) or α2-noradrenergic receptors (idazoxan). Finally, with the method of in vivo microdialysis, the increase in spinal NA and 5-HT levels after intraperitoneal (i.p.) delivery of duloxetine were investigated. The results showed that intrathecal (i.t.) or i.p. delivery of duloxetine produced an anti-hyperalgesic effect in a dose-dependent manner. The anti-hypersensitivity effect of duloxetine was partly attenuated by pretreatment with ketanserin or idazoxane. Microdialysis study revealed that 5-HT and NA concentrations at the spinal dorsal horn were increased, peaking at 30min after i.p. injection of 20mg/kg duloxetine. These findings indicate that duloxetine inhibits POP by increasing spinal NA and 5-HT levels and activating spinal 5-HT2A or α2-noradrenergic receptors.

Synergistic analgesia of duloxetine and celecoxib in the mouse formalin test: a combination analysis.

Duloxetine, a serotonin and noradrenaline reuptake inhibitor, and celecoxib, a non-steroidal anti-inflammatory drug, are commonly used analgesics for persistent pain, however with moderate gastrointestinal side effects or analgesia tolerance. One promising analgesic strategy is to give a combined prescription, allowing the maximal or equal efficacy with fewer side effects. In the current study, the efficacy and side effects of combined administration of duloxetine and celecoxib were tested in the mouse formalin pain model. The subcutaneous (s.c.) injection of formalin into the left hindpaw induced significant somatic and emotional pain evaluated by the biphasic spontaneous flinching of the injected hindpaw and interphase ultrasonic vocalizations (USVs) during the 1 h after formalin injection, respectively. Pretreatment with intraperitoneal (i.p.) injection of duloxetine or celecoxib at 1 h before formalin injection induced the dose-dependent inhibition on the second but not first phase pain responses. Combined administration of duloxetine and celecoxib showed significant analgesia for the second phase pain responses. Combination analgesia on the first phase was observed only with higher dose combination. A statistical difference between the theoretical and experimental ED50 for the second phase pain responses was observed, which indicated synergistic interaction of the two drugs. Concerning the emotional pain responses revealed with USVs, we assumed that the antinociceptive effects were almost completely derived from duloxetine, since celecoxib was ineffective when administered alone or reduced the dosage of duloxetine when given in combination. Based on the above findings, acute concomitant administration of duloxetine and celecoxib showed synergism on the somatic pain behavior but not emotional pain behaviors.