Korean Journal of Pain最新文献

The application of ultrasound (US) in pain medicine has been a rapidly growing field since the 2000s. Musculoskeletal injections, peripheral nerve blocks, and neuraxial injections under US guidance have been acknowledged for managing chronic pain. Although many studies on US-guided pain procedures have been published, there needs to be a classification system to evaluate which image device, the US or fluoroscopy, is clinically and technically better in various pain interventions. Therefore, this narrative review introduces the classification system for the US-guided pain procedures according to their clinical and technical outcomes and designates US-guided pain procedures into one of the four categories by reviewing previous prospective randomized comparative trials.

Background: Little is known about the frequency and impact of the persistent headache and about the incidence of chronic daily headache (CDH) after coronavirus disease 2019 (COVID-19). The aim of this prospective cohort study was to assess the incidence, risk factors, characteristics, and impact of CDH in patients with COVID-19.

Methods: In the first stage, 288 patients were interviewed by telephone after the acute phase of COVID-19. Subsequently, 199 patients who presented headache were reinterviewed at least one year after COVID-19. Headaches that persisted beyond the acute phase of COVID-19 for three or more months and presented frequency ≥ 45 days over the first three months were considered to be CDH.

Results: One hundred and twenty-three patients were included, 56% were females; median age: 50 years (25th and 75th percentile: 41;58). The headache persisted beyond the acute phase of COVID-19 in 52%, and 20.3% had CDH (95% confidence interval: 13.6-28.2). Individuals who previously had headaches and who had headaches of greater intensity during the acute phase were at higher risk of developing CDH. The group with CDH included more females, greater impact of headache, more persistence of headache beyond the 120th day of COVID-19 and less throbbing headache than did the other individuals whose headache persisted.

Conclusions: Patients who had COVID-19 had a high incidence of CDH. Previous headache and greater intensity of headache were associated with higher risk of CDH.

Background: Ferrostatin-1 and liproxstatin-1, both ferroptosis inhibitors, protect cells. Liproxstatin-1 decreases morphine tolerance. Yet, ferrostatin-1's effect on morphine tolerance remains unexplored. This study aimed to evaluate the influence of ferrostatin-1 on the advancement of morphine tolerance and understand the underlying mechanisms in male rats.

Methods: This experiment involved 36 adult male Wistar albino rats with an average weight ranging from 220 to 260 g. These rats were categorized into six groups: Control, single dose ferrostatin-1, single dose morphine, single dose ferrostatin-1 + morphine, morphine tolerance (twice daily for five days), and ferrostatin-1 + morphine tolerance (twice daily for five days). The antinociceptive action was evaluated using both the hot plate and tail-flick tests. After completing the analgesic tests, tissue samples were gathered from the dorsal root ganglia (DRG) for subsequent analysis. The levels of glutathione, glutathione peroxidase 4 (GPX4), and nuclear factor erythroid 2-related factor 2 (Nrf2), along with the measurements of total oxidant status (TOS) and total antioxidant status (TAS), were assessed in the tissues of the DRG.

Results: After tolerance development, the administration of ferrostatin-1 resulted in a significant decrease in morphine tolerance (P < 0.001). Additionally, ferrostatin-1 treatment led to elevated levels of glutathione, GPX4, Nrf2, and TOS (P < 0.001), while simultaneously causing a decrease in TAS levels (P < 0.001).

Conclusions: The study found that ferrostatin-1 can reduce morphine tolerance by suppressing ferroptosis and reducing oxidative stress in DRG neurons, suggesting it as a potential therapy for preventing morphine tolerance.

Background: Tolerance to the analgesic effects of opioids and non-steroidal anti-inflammatory drugs (NSAIDs) is a major concern for relieving pain. Thus, it is highly valuable to find new pharmacological strategies for prolonged therapeutic procedures. Biguanide-type drugs such as metformin (MET) are effective for neuroprotection and can be beneficial for addressing opioid tolerance in the treatment of chronic pain. It has been proposed that analgesic tolerance to NSAIDs is mediated by the endogenous opioid system. According to the cross-tolerance between NSAIDs, especially sodium salicylate (SS), and opiates, especially morphine, the objective of this study was to investigate whether MET administration can reduce tolerance to the anti-nociceptive effects of SS.

Methods: Fifty-six male Wistar rats were used in this research (weight 200-250 g). For induction of tolerance, SS (300 mg/kg) was injected intraperitoneally for 7 days. During the examination period, animals received MET at doses of 50, 75, or 100 mg/kg for 7 days to evaluate the development of tolerance to the analgesic effect of SS. The hot plate test was used to evaluate the drugs' anti-nociceptive properties.

Results: Salicylate injection significantly increased hot plate latency as compared to the control group, but the total analgesic effect of co-treatment with SS + Met50 was stronger than the SS group. Furthermore, the effect of this combination undergoes less analgesic tolerance over time.

Conclusions: It can be concluded that MET can reduce the analgesic tolerance that is induced by repeated intraperitoneal injections of SS in Wister rats.

Background: Radiofrequency ablation is an effective treatment modality in the symptomatic treatment of knee osteoarthritis. Our aim was to compare the efficacy of radiofrequency ablation of the superomedial and inferomedial genicular nerves (2 branches) with the superolateral, superomedial, and inferomedial genicular nerves (3 branches) and to show whether the 2-branch procedure is inferior to the 3-branch procedure.

Methods: This study is a prospective, randomized, single-blind clinical study. Eligible participants were randomized into 2 groups: group A, which applied the procedure to the superomedial and inferomedial genicular nerves, and group B, which applied it to the superomedial, superolateral and inferomedial genicular nerves. Pain was evaluated with the numerical rating scale, quality of life with the Short Form-36 (SF-36), and disability with the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index before, and at 1 and 3 months after the procedure.

Results: A total of 41 patients were included. There were no differences between the groups except for the SF-36 physical health sub-score at baseline. A significant improvement was seen in the numeric rating scale (NRS) score, SF-36 sub-scores, WOMAC Index total, as well as pain and physical function scores in both groups, though no significant difference was detected between the groups during follow-up.

Conclusions: Although we were unable to establish the noninferiority of conventional radiofrequency ablation (CRFA) applied to 2 branches to CRFA applied to 3 branches, in this trial, significant and similar improvement was observed in NRS, WOMAC total, pain, and physical function and SF-36 scores in both groups.

This review explores the essential methodologies for effective postoperative pain management, focusing on the need for thorough pain assessment tools, as underscored in various existing guidelines. Herein, the strengths and weaknesses of commonly used pain scales for postoperative pain-the Visual Analog Scale, Numeric Rating Scale, Verbal Rating Scale, and Faces Pain Scale-are evaluated, highlighting the importance of selecting appropriate assessment tools based on factors influencing their effectiveness in surgical contexts. By emphasizing the need to comprehend the minimal clinically important difference (MCID) for these scales in evaluating new analgesic interventions and monitoring pain trajectories over time, this review advocates recognizing the limitations of common pain scales to improve pain assessment strategies, ultimately enhancing postoperative pain management. Finally, five recommendations for pain assessment in research on postoperative pain are provided: first, selecting an appropriate pain scale tailored to the patient group, considering the strengths and weaknesses of each scale; second, simultaneously assessing the intensity of postoperative pain at rest and during movement; third, conducting evaluations at specific time points and monitoring trends over time; fourth, extending the focus beyond the intensity of postoperative pain to include its impact on postoperative functional recovery; and lastly, interpreting the findings while considering the MCID, ensuring that it is clinically significant for the chosen pain scale. These recommendations broaden our understanding of postoperative pain and provide insights that contribute to more effective pain management strategies, thereby enhancing patient care outcomes.