Regional vitamin C in Bier block reduces the incidence of CRPS-1 following distal radius fracture surgery

Efficacy of vitamin C supplementation in preventing and treating complex regional pain syndrome type I (CRPS-I) in Orthopedic patients: A systematic review and meta-analysis

AIM

Complex regional pain syndrome type I (CRPS-I) is a specific type of persistent pain which is often caused by fracture and surgery. There is no effective curative therapy available. However some studies have indicated that Vitamin C (VC) can reduce the incidence of CRPS-I. This study's objective is to investigate the effectiveness VC in preventing and treating CRPS-I.

DESIGN

An Systematic review and Meta-analysis was done.

DATA SOURCES

Primary research studies from PubMed, Scopus, Web of Science, ProQuest, Embase database, and Cochran Library, and Google Scholar were reviewed. This search was conducted until March 27, 2024. This study was conducted without any language, place, and time restrictions. Study results were meta-analyzed with using effect sizes. To evaluate heterogeneity, we employed the Cochrane Q test and the I2 index.

RESULTS

In our systematic review, 3947 articles were initially identified, with 3939 excluded for not meeting inclusion criteria, resulting in 8 studies being critically evaluated using Cochran's risk of bias checklist. The meta-analysis revealed that VC supplementation have effect on reducing CRPS-I post-limb surgery but this result shows that the pooled effect size is not statistically significant. The heterogeneity of the studies was low (I2 = 26.28%, p = 0.22). Publication bias was detected, indicating asymmetry in the funnel plot.

CONCLUSION

The results of our study showed the positive effect of VC supplementation in reducing the prevalence of CRPS-I after limb surgery.

Efficacy of N-acetylcysteine in reducing inflammation and oxidative stress to prevent complex regional pain syndrome type 1

This study aimed to evaluate the effectiveness of N-acetylcysteine (NAC) in preventing complex regional pain syndrome type 1 (CRPS-1) by reducing proinflammatory cytokines and oxidative stress markers in patients with distal radius fractures. A retrospective single-center study at Bursa City Hospital involves patients over 50 years of age with distal radius fractures treated between January 2021 and December 2023. A total of 60 patients (mean age, 62.8 ± 5.1 years; 26 males and 34 females) were analyzed. Patients were divided into 2 groups: the NAC group (31 patients receiving 600-mg NAC daily for 3 months) and the control group (29 patients with no prophylactic medication). CRPS-1 diagnosis was based on Budapest criteria during multiple follow-up visits. Serum levels of interleukin (IL)-1 beta, IL-6, tumor necrosis factor-alpha (TNF-α), total oxidant status (TOS), and total antioxidant status (TAS) were measured at baseline and study end point. CRPS-1 positive patients had significantly higher levels of IL-6, TNF-α, and IL-1 (P < .001 for all), higher TOS (P < .001) and oxidative stress index (P < .001), and lower TAS (P < .001) compared with CRPS-1 negatives. The incidence of CRPS-1 was significantly lower in the NAC group (9.7%) compared with the control group (31.0%; P = .039). Logistic regression indicated a 78% reduction in CRPS-1 odds ratio with NAC treatment (odds ratio, 0.219 [95% confidence interval, 0.053-0.895]; P = .0322). NAC significantly reduced end-point levels and changes in IL-6 (P < .001), TNF-α (P < .001), and IL-1 (P = .038) and improved oxidative stress markers, showing higher TAS (P < .001), lower TOS (P < .001), and oxidative stress index (P < .001) compared with controls. NAC significantly reduced the risk of developing CRPS-1 by decreasing levels of proinflammatory cytokines and oxidative stress. This study highlights NAC's potential as a preventive treatment for CRPS-1 and emphasizes the importance of early intervention.

The Use of High-Dose Intravenous L-Ascorbate in Pain Therapy: Current Evidence from the Literature

INTRODUCTION

Pain is the most common reason for seeking medical treatment. Despite extensive research efforts and effective analgesics modulating pain, there is still a major therapeutic gap in addressing the root causes of pain. Pain is associated with tissue damage induced by oxidative stress and induction of inflammatory mediators following high consumption of antioxidants. The role of antioxidants in general, and the administration of L-ascorbate in particular, is still controversially discussed and underestimated in the daily clinical practice.

METHODS

The current literature on the therapeutic effect of L-ascorbate, ascorbic acid, and vitamin C on various pain conditions was evaluated against the background of evidence-based medicine. Those articles, obtained from systematic search in PubMed, were critically assessed and rated in terms of evidence level and methodological quality by two independent experts. The primary purpose of this work was to establish specific pain therapy guidance for intravenous L-ascorbate.

RESULTS

A PubMed search revealed 14 suitable articles comprising controlled clinical trials and meta-analyses. An additional ten publications could be identified via secondary literature. There is supporting evidence for the efficacy of ascorbate treatment in inflammatory pain conditions, in the complex regional pain syndrome, in post zoster neuralgia, in neuropathic pain, in post-operative pain conditions, and in tumor-related pain. However, the considered studies differ in the type of administration, in dosage, in duration of treatment, as well as in quality of research. Despite all study heterogeneity, it became evident that research of high scientific quality is in support of the efficacy of L-ascorbate in pain treatment.

DISCUSSION

Oxidative stress is present in almost all pain conditions. Because oral administration of most magistral formulas of vitamin C does not provide biological availability, parenteral administration should be preferred and can be supported by an oral dose with high bioavailability on days without intravenous treatment. L-ascorbate should be preferred for parenteral high dosage, rather than ascorbic acid, as it does not release acid valences under physiological conditions.

CONCLUSIONS

L-ascorbate is an effective, safe, and economically favorable integrative treatment option for various pain conditions, addressing the root cause of tissue damage and inflammatory mediator burst.

Complex Regional Pain Syndrome: Evidence-Based Advances in Concepts and Treatments

PURPOSE OF REVIEW

This review presents the most current information about the epidemiology of complex regional pain syndrome (CRPS), classification and diagnostic criteria, childhood CRPS, subtypes, pathophysiology, conventional and less conventional treatments, and preventive strategies.

RECENT FINDINGS

CRPS is a painful disorder with multifactorial pathophysiology. The data describe sensitization of the central and peripheral nervous systems, inflammation, possible genetic factors, sympatho-afferent coupling, autoimmunity, and mental health factors as contributors to the syndrome. In addition to conventional subtypes (type I and type II), cluster analyses have uncovered other proposed subtypes. Prevalence of CRPS is approximately 1.2%, female gender is consistently associated with a higher risk of development, and substantial physical, emotional, and financial costs can result from the syndrome. Children with CRPS seem to benefit from multifaceted physical therapy leading to a high percentage of symptom-free patients. The best available evidence along with standard clinical practice supports pharmacological agents, physical and occupational therapy, sympathetic blocks for engaging physical restoration, steroids for acute CRPS, neuromodulation, ketamine, and intrathecal baclofen as therapeutic approaches. There are many emerging treatments that can be considered as a part of individualized, patient-centered care. Vitamin C may be preventive. CRPS can lead to progressively painful sensory and vascular changes, edema, limb weakness, and trophic disturbances, all of which substantially erode healthy living. Despite some progress in research, more comprehensive basic science investigation is needed to clarify the molecular mechanisms of the disease so that targeted treatments can be developed for better outcomes. Incorporating a variety of standard therapies with different modes of action may offer the most effective analgesia. Introducing less conventional approaches may also be helpful when traditional treatments fail to provide sufficient improvement.

Effect of Perioperative Vitamin C on the Incidence of Complex Regional Pain Syndrome: A Systematic Review and Meta-Analysis

Complex regional pain syndrome type 1 (CRPS-I) is a complex complication that occurs after limb extremity surgeries. Controversy exists regarding the effectiveness of vitamin C in reducing that condition. Therefore, we conducted this systematic review and meta-analysis to assess the role of vitamin C on CRPS-I and functional outcomes after distal radius, wrist, foot, and ankle surgeries. We searched Medline (via PubMed), Embase, the Cochrane Library, Clinicaltrial.gov, and Google Scholar for relevant studies comparing perioperative vitamin C versus placebo after distal radius, wrist, foot, and ankle surgeries from infinity to May 2021. Continuous data such as functional outcomes and pain scores were pooled as mean differences, while dichotomous variables such as the incidence of complex regional pain syndrome and complications were pooled as odds ratios, with 95% confidence interval, using R software (meta package, version 4.9-0) for Windows. Eight studies were included. The timeframe for vitamin C administration in each study ranged from 42 to 50 days postinjury and/or surgical fixation. The effect size showed that vitamin C was associated with a decreased rate of CRPS-1 than placebo (odds ratio 0.33, 95% confidence interval [0.17, 0.63]). No significant difference was found between vitamin C and placebo in terms of complications (odds ratio 1.90, 95% confidence interval [0.99, 3.65]), functional outcomes (mean difference 6.37, 95% confidence interval [-1.40, 14.15]), and pain scores (mean difference -0.14, 95% confidence interval [-1.07, 0.79]). Overall, vitamin C was associated with a decreased rate of CRPS-I than placebo, while no significant difference was found regarding complications, functional outcomes, and pain scores. These results hold true when stratifying fracture type (distal radius, ankle, and foot surgeries) and vitamin C dose (500 mg or 1 g).

Oxidative stress is associated with characteristic features of the dysfunctional chronic pain phenotype

ABSTRACT

The dysfunctional chronic pain (Dysfunctional CP) phenotype is an empirically identifiable CP subtype with unclear pathophysiological mechanisms that cuts across specific medical CP diagnoses. This study tested whether the multidimensional pain and psychosocial features that characterize the dysfunctional CP phenotype are associated broadly with elevated oxidative stress (OS). Measures of pain intensity, bodily extent of pain, catastrophizing cognitions, depression, anxiety, sleep disturbance, pain interference, and function were completed by 84 patients with chronic osteoarthritis before undergoing total knee arthroplasty. Blood samples were obtained at the initiation of surgery before incision or tourniquet placement. Plasma levels of F2-isoprostanes and isofurans, the most highly specific measures of in vivo OS, were quantified using gas chromatography/negative ion chemical ionization mass spectrometry. The results indicated that controlling for differences in age, sex, and body mass index, higher overall OS (mean of isoprostanes and isofurans) was associated with significantly (P < 0.05) greater pain intensity, more widespread pain, greater depressive symptoms and pain catastrophizing, higher pain interference, and lower function. OS measures were not significantly associated with sleep disturbance or anxiety levels (P >0.10). The results build on prior case-control findings suggesting that presence of a CP diagnosis is associated with elevated OS, highlighting that it may specifically be individuals displaying characteristics of the dysfunctional CP phenotype who are characterized by elevated OS. Clinical implications of these findings remain to be determined.