Background: Chemotherapy-induced neuropathic pain is a disabling condition following cancer treatment. Vincristine has more neurotoxicity than other vinca alkaloid agents. This study evaluated the correlation of different doses of nefopam with antiallodynic effects in a mouse vincristine neuropathy model. Methods: A peripheral neuropathic mouse model was made by intraperitoneal injection of vincristine (0.1 mg/kg/day; 5-day-on, 2-day-off schedule over 12 days). After the development of allodynia, mice were injected intraperitoneally with 0.9% normal saline (NS group) or various doses (10, 30, 60 mg/kg) of nefopam (Nefopam group). We examined allodynia using von Frey hairs pre-administration and at 30, 60, 90, 120, 180, 240 mins, and 24 hrs after drug administration. We also measured the neurokinin-1 receptor concentrations in the spinal cord to confirm the antiallodynic effect of nefopam after drug administration. Results: The peripheral neuropathic mouse model showed prominent mechanical allodynia. Intraperitoneal nefopam produced a clear dose-dependent increase in paw withdrawal threshold compared with pre-administration values and versus the NS group. The concentration of neurokinin-1 receptor was significantly decreased in the Nefopam group (P<0.05). Conclusion: Intraperitoneally administered nefopam yielded a dose-dependent attenuation of mechanical allodynia and decreased neurokinin-1 receptor concentration, suggesting that the neurokinin-1 receptor is involved in the antiallodynic effects of nefopam in vincristine neuropathy.

Despite technical advancements in the perioperative management of cancer surgery, postoperative pain remains a significant clinical issue. We examined the diagnostic value of the intraoperative perfusion index for predicting acute postoperative pain in patients undergoing laparoscopic colorectal cancer surgery. We retrospectively analyzed data for 105 patients who had undergone laparoscopic colorectal cancer surgery. Patients with pain scores <7 and ≥7 on a 10-point scale upon arrival in the postoperative anesthesia care unit (PACU) were categorized into the N and P groups, respectively. The perfusion index value was extracted prior to intubation, at the start and end of surgery, and after extubation. To minimize individual variance in the absolute value of the perfusion index, we calculated the perfusion index change ratio. A total of 98 patients were examined. Among them, 50 (51.0%) and 48 (49.0%) patients reported pain scores of <7 and ≥7 upon arrival at the PACU, respectively. Fentanyl consumption during the intraoperative and PACU periods was significantly higher in Group P than in Group N (p < 0.001). The perfusion index change ratios did not significantly differ between the groups. The intraoperative perfusion index change ratios do not correlate with acute postoperative pain following laparoscopic colorectal cancer surgery.

What is known and objective Pain management for complex regional pain syndrome (CRPS) is challenging. When added to local anaesthetics, dexmedetomidine prolongs the duration of the block and improves analgesia. The effect of long‐term dexmedetomidine use in the brachial plexus block (BPB) for CRPS is unknown. Case description Here, we describe a case of satisfactory pain relief after supraclavicular BPB with dexmedetomidine every 1‐3 months over 2 years (10 treatments), in a patient with severe upper extremity CRPS‐related pain. What is new and conclusion Repeated, long‐term, perineural administration of dexmedetomidine with BPB may be suitable for alleviating refractory CRPS pain.

Although there are various drugs for Neuropathic pain (NP), the effects of single drugs are often not very satisfactory. The analgesic effects of different combinations of pregabalin, duloxetine, and tramadol or the combination of all three are still unclear. Mixtures of two or three drugs at low and high concentrations (7.5, 10, 15, and 20 mg/kg pregabalin; 7.5, 10, 15, and 30 mg/kg duloxetine; 5 and 10 mg/kg tramadol) were administered to chronic postischemic pain (CPIP) and spinal nerve ligation (SNL) model mice. The effects of these combinations of drugs on mechanical allodynia were investigated. The expression of the glial fibrillary acidic protein (GFAP) in the spinal cord and dorsal root ganglia (DRGs) was measured. The combination of pregabalin, duloxetine, and tramadol significantly alleviated mechanical hyperalgesia in mice with CPIP and SNL. After the administration of this drug combination, the expression of GFAP in the spinal cord and DRGs was lower in the CPIP and SNL model mice than in control mice. This result suggests that the combination of these three drugs may be advantageous for the treatment of NP because it can reduce side effects by preventing the overuse of a single drug class and exert increased analgesic effects via synergism.

Despite rapid advancements in laparoscopic surgical techniques and perioperative management, postoperative pain remains a significant clinical issue. We examined the analgesic efficacy of nefopam as an adjuvant in patient-controlled analgesia (PCA) for acute postoperative pain in patients undergoing laparoscopic colorectal cancer surgery. We retrospectively analyzed the medical records of 120 patients who did or did not receive 80 mg of nefopam as an adjuvant in fentanyl PCA; they were allocated to the nefopam (n = 60) or non-nefopam group (n = 60). The demographic, clinical, and anesthetic data, with data on pain severity and opioid administration at the postoperative anesthesia care unit (PACU) on postoperative days (PODs) 1, 3, and 5, were compared between the groups. The pain score and opioid administration did not differ at the PACU or on PODs 1, 3, or 5. The day of PCA discontinuation, time to pass flatus, length of the hospital stay, and incidence of nausea/vomiting, dizziness, and headache also did not differ between the groups. Fentanyl PCA with 80 mg of nefopam as an adjuvant did not have a superior analgesic effect after laparoscopic colorectal cancer surgery.

Rationale: Spinal cord stimulation (SCS) is one of the invasive treatments of complex regional pain syndrome (CRPS). The positive effect has been observed for several years after implantation. However, infection is a common cause of SCS failure and device removal. Patient concerns: Here we describe a case of latent infection at the implantable generator pocket site 9 years after SCS implantation in a patient with CRPS. Diagnoses: A 52-year-old patient was diagnosed with type 1 CRPS. The right foot pain was intractable with standard treatments. SCS implantation was performed and SCS worked well without complication. Nine years later, the patient revisited due to pain, tenderness, and redness at the abdominal wall for 2 weeks. The right foot pain was maintained with NRS 4 for 8 years, and the stimulation stopped 1 year back. SCS infection was diagnosed. Interventions: The patient underwent SCS removal surgery. Outcomes: All SCS devices were removed successfully. The patient was discharged without any complications. Conclusions: While uncommon, infection after SCS implantation can occur even 9 years later. Immediate diagnosis, proper antibiotics, and surgical removal could be needed to prevent further spread of infection and better prognosis.

BackgroundIn Korea, anesthesiologists are expected to be mainstream pain medicine (PM) practitioners. However, anesthesiology and pain medicine (APM) residency programs mostly emphasize anesthesia learning, leading to insufficient PM learning. Therefore, this study evaluated the current status of PM training in APM residency programs in 10 Korean university hospitals.MethodsOverall, 156 residents undergoing APM training participated anonymously in our survey, focusing on PM training. We assessed the aim, satisfaction status, duration, opinion on duration, desired duration, weaknesses of the training programs and plans of residents after graduating. We divided the residents into junior (first and second year) and senior (third and fourth year). Survey data were compared between groups.ResultsSenior showed significantly different level of satisfaction grade than did junior (p=0.026). Fifty-seven (81.4%) residents in junior and forty (46.5%) residents in senior underwent PM training for ≤2 months. Most (108; 69.2%) residents felt that the training period was too short for PM learning and 95 (60.9%) residents desired a training period of ≥6 months. The most commonly expressed weakness of the training was low interventional opportunity (29.7%), followed by short duration (26.6%). After residency, 80 (49.1%) residents planned to pursue a fellowship.ConclusionsDissatisfaction with PM training was probably due to a structural tendency of the current program towards anesthesia training and insufficient clinical experience, which needs to be rectified, with a change in PM curriculum.

Background An epidural blood patch (EBP) is a procedure to treat intracranial hypotension that does not respond to conservative treatment. EBPs are commonly repeated when the symptoms persist. In this study, we used a large single-center retrospective cohort and evaluated the factors associated with repeated EBPs. Methods From January 2010 to December 2020, a total of 596 patients were treated with EBPs for intracranial hypotension. We evaluated the factors associated with repeated EBPs in the entire population, in patients with spontaneous intracranial hypotension (SIH), and in those with available myelographies. Results In a total of 596 patients, 125 (21.1%) patients required repeated EBPs, and 96/278 (34.5%) in SIH and 29/314 (9.2%) in iatrogenic population. In patients with SIH, international normalized ratio (INR) and cerebrospinal fluid (CSF) leakage on myelographies consistently exhibited significant associations (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.02–1.87; P = 0.043 and OR, 2.18; 95% CI, 1.28–3.69; P = 0.004). In patients with iatrogenic injury, INR and CSF leakage on myelogram did not show difference in repeated EBPs. Conclusions Repeated EBPs may be more frequently required in patients with SIH. Prolonged INR and CSF leakage were associated with repeated EBPs in patient with SIH. Further studies are needed to determine factors associated with repeated EBP requirements.