Background: We investigated the analgesic efficacy of bilateral superficial cervical plexus block in patients undergoing thyroidectomy and to determine whether it reduces the adverse effects of general anesthesia.Methods: We prospectively recruited 162 patients who underwent elective thyroid operations from March 2006 to October 2007. They were randomly assigned to receive a bilateral superficial cervical block (12 ml per side) with isotonic saline (group A; n = 56), bupivacaine 0.5% (group B; n = 52), or levobupivacaine 0.5% (group C; n = 54) after induction of general anesthesia. The analgesic efficacy of the block was assessed with: intraoperative anesthetics (desflurane), numbers of patients needing postoperative analgesics, the time to the first analgesics required, and pain intensity by visual analog scale (VAS). Postoperative nausea and vomiting (PONV) for 24 h were also assessed by the “PONV grade.” We also compared hospital stay, operative time, and discomfort in swallowing.Results: There were no significant differences in patient characteristics. Each average end‐tidal desflurane concentration was 5.8, 3.9, and 3.8% in groups A, B, and C, respectively (p < 0.001). Fewer patients in groups B and C required analgesics (A: B: C = 33:8:7; p < 0.001), and it took longer before the first analgesic dose was needed postoperatively (group A: B: C = 82.1:360.8:410.1 min; p < 0.001). Postoperative pain VAS were lower in groups B and C for the first 24 h postoperatively (p < 0.001). Incidences of overall and severe PONV were lower, however, there were not sufficient numbers of patients to detect differences in PONV among the three groups. Hospital stay was shorter in group B and group C (p = 0.011). There was no significant difference in operative time and postoperative swallowing pain among the three groups.Conclusions: Bilateral superficial cervical plexus block reduces general anesthetics required during thyroidectomy. It also significantly lowers the severity of postoperative pain during the first 24 h and shortens the hospital stay.

Pulsed radiofrequency (PRF) is effective in the treatment of neuropathic pain in clinical practice. Its application to sites proximal to nerve injury can inhibit the activity of extra-cellular signal-regulated kinase (ERK) for up to 28 days. The spared nerve injury (SNI)+ immPRF group (immediate exposure to PRF for 6 min after SNI) exhibited a greater anti-allodynic effect compared with the control group (SNI alone) or the SNI + postPRF group (application of PRF for 6 min on the 14th day after SNI). Insulin-like growth factor 2 (IGF2) was selected using microarray assays and according to web-based gene ontology annotations in the SNI + immPRF group. An increase in IGF2 and activation of ERK1/2 were attenuated by the immPRF treatment compared with an SNI control group. Using immunofluorescent staining, we detected co-localized phosphorylated ERK1/2 and IGF2 in the dorsal horn regions of rats from the SNI group, where the IGF2 protein predominantly arose in CD11b- or NeuN-positive cells, whereas IGF2 immunoreactivity was not detected in the SNI + immPRF group. Taken together, these results suggest that PRF treatment immediately after nerve injury significantly inhibited the development of neuropathic pain with a lasting effect, most likely through IGF2 down-regulation and the inhibition of ERK1/2 activity primarily in microglial cells.

Pulsed radiofrequency (PRF) works by delivering short bursts of radiofrequency to a target nerve, thereby affecting nerve signal transduction to reduce pain. Although preliminary clinical investigations have shown that PRF treatment can be used safely as an alternative interventional treatment in patients with refractory pain conditions, unexpected damage to a normal nerve/ganglion is still one of the possible complications of using the PRF strategy. Noxious pain may also be triggered if PRF treatment accidentally damages an intact nerve. However, few studies in the literature have described the intracellular modifications that occur in neuronal cells after PRF stimulation. Therefore, in this study, we evaluated the effects of PRF on unimpaired nerve function and investigated the potential mechanisms of PRF-induced pain. Wistar rats were stimulated with 30–60 V of PRF for 6 min, and mechanical allodynia, cold hypersensitivity, cytokine and matrix metalloproteinase (MMP) production, and mitogen-activated protein kinase activity (p38 MAPK, ERK1/2, JNK/SAPK) were analyzed. The results indicated that PRF stimulation induced a significant algesic effect and nociceptive response. In addition, the protein array and Western blotting analyses showed that the clinical application of 60 V of PRF can induce the activation of MAPKs and the production of inflammatory cytokines and MMPs in the lumbar dorsal horn, which is necessary for nerve inflammation, and it can be suppressed by MAPK antagonist treatment. These results indicate that PRF stimulation may induce inflammation of the intact nerve, which in turn causes inflammatory pain. This conclusion can also serve as a reminder for PRF treatment of refractory pain.

Introduction Patients undergoing upper extremity fracture surgery (UEFS) commonly suffer from unbearable acute pain. Opioids remain the mainstay of moderate to severe pain alleviation, although there is a growing concern regarding the increasing trend in misuse and abuse. This study aimed to observe the safety and efficacy of dinalbuphine sebacate (DS), a novel extended-release analgesic, along with multimodal analgesia (MMA) for post-UEFS pain control. Methods We retrospectively reviewed the records of patients undergoing UEFS between August 2020 and January 2021. Eligible patients were included and divided into two groups, depending on the analgesic regimen. In the DS group, 150 mg DS was administered intramuscularly at least 12 h pre-operatively, while in the conventional analgesia (CA) group, 40 mg parecoxib was given within 3 h before surgery. Intraoperative fentanyl administration was guided by the Analgesia Nociception Index System in both groups. For breakthrough pain, fentanyl was used as rescue medicine in the postanaesthesia care unit while tramadol and parecoxib were administered in the ward. Results Forty-nine patients were allocated to the DS group and 60 patients were allocated to the CA group. In comparison with the CA group, the proportion of patients requiring opioids for breakthrough pain post-operatively was significantly lower in the DS group (fentanyl: 31% vs. 68%, p < 0.001; tramadol: 27% vs. 70%, p < 0.001). The DS group also consumed lower amounts of post-operative rescue opioids. Furthermore, both mean worst and least pain scores were significantly lower in the DS group from post-operative day (POD) 1 to POD 5. There was no significant difference in intraoperative consumption of fentanyl or incidence of adverse events. Conclusion This result suggests that extended-release DS is a suitable analgesic incorporated in MMA and a promising solution to the misuse and abuse of opioids.

The aim of this study was to compare the short-term outcomes between 2 different treatments for unilateral chronic shoulder pain of myofascial origin, that is, local tender area related meridians (LTARMs) treatment and collateral meridian therapy (CMT), which were performed 6 times over a period of 4 weeks.Seventy patients with unilateral shoulder pain of chronic myofascial origin were enrolled. The patients were randomly assigned to 2 different treatment groups: 1 group received CMT (n = 35) and the other received LTARM (n = 35). Before and after the 2 treatment processes, all patients rated their overall pain intensity on a visual analogue scale (VAS) and a validated 13-question shoulder pain and disability index (SPADI) questionnaire was used to measure shoulder pain and functional impairment after therapy for 4 weeks.After CMT, the pain intensity was reduced after CMT. VAS score is reduced from 5.90 ± 2.07 (a mean of 5.90 and standard deviation of 2.07) to 3.39 ± 1.2. This was verified by the SPADI pain subscale scores (from 0.58 ± 0.193 to 0.33 ± 0.14). The pain-relief effect of CMT was significantly better than that of LTARM (VAS score from 5.78 ± 1.64 to 4.58 ± 1.40; P < 0.005; SPADI pain subscale score from 0.58 ± 0.16 to 0.45 ± 0.14, P < 0.001). In addition, the VAS scores of patients changed considerably in the CMT group after 4 weeks of treatment, where 63% of patients felt no or mild pain, whereas the VAS scores for moderate pain were even higher in the LTARM group in 75% of patients (P < 0.001). Moreover, the SPADI disability subscale scores improved significantly in the CMT group because of their greater mobility associated with shoulder impairment (disability score: from 0.58 ± 0.20 to 0.35 ± 0.14) than those in the LTARM group (disability score: from 0.55 ± 0.17 to 0.44 ± 0.14, P < 0.001).CMT may be more effective in reducing chronic shoulder pain of myofascial origin than the LTARM treatment, where treatment with the former resulted in better functional recovery after 4 weeks than the latter.