ArticlePain medicine (Malden, Mass.)2023
Sympathetic Blocks as a Predictor for Response to Ketamine Infusion in Patients with Complex Regional Pain Syndrome: A Multicenter Study.
Article in Pain medicine (Malden, Mass.), 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06073795 (Ultrasound Guided Versus Fluoroscopy Guided Lumber Sympathetic Block in Chronic Lower Limb Ischemia), which is not on this map. Cited by 5 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Ultrasound Guided Versus Fluoroscopy Guided Lumber Sympathetic Block in Chronic Lower Limb Ischemia
Who cites it
5 citing papers in PubMed, 22 citations in OpenAlex.
- CMS proposed restrictions on peripheral nerve blocks and procedures for chronic pain: clinical, ethical, and policy implications for millions of Americans.Pain medicine (Malden, Mass.) · 2026Article
- An Emerging Perspective on the Role of Fascia in Complex Regional Pain Syndrome: A Narrative Review.International journal of molecular sciences · 2025Review
- Clinical and Molecular Barriers to Understanding the Pathogenesis, Diagnosis, and Treatment of Complex Regional Pain Syndrome (CRPS).International journal of molecular sciences · 2025Article
- Pain can't be carved at the joints: defining function-based pain profiles and their relevance to chronic disease management in healthcare delivery design.BMC medicine · 2024Article
- Mechanisms of complex regional pain syndrome.Frontiers in pain research (Lausanne, Switzerland) · 2024Review
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Authors and funding
10 authors at 3 institutions in 2 countries.
Funding
Abstract
backgroundKetamine infusions are frequently employed for refractory complex regional pain syndrome (CRPS), but there are limited data on factors associated with treatment response. Sympathetic blocks are also commonly employed in CRPS for diagnostic and therapeutic purposes and generally precede ketamine infusions.
objectivesWe sought to determine whether demographic and clinical factors, and technical and psychophysical characteristics of sympathetic blocks are associated with response to ketamine infusion.
methodsIn this multi-center retrospective study, 71 patients who underwent sympathetic blocks followed by ketamine infusions at 4 hospitals were evaluated. Sympathetically maintained pain (SMP) was defined as ≥ 50% immediate pain relief after sympathetic block and a positive response to ketamine was defined as ≥ 30% pain relief lasting over 3 weeks.
resultsFactors associated with a positive response to ketamine in univariable analysis were the presence of SMP (61.0% success rate vs 26.7% in those with sympathetically independent pain; P = .009) and post-block temperature increase (5.66 ± 4.20 in ketamine responders vs 3.68 ± 3.85 in non-responders; P = .043). No psychiatric factor was associated with ketamine response. In multivariable analysis, SMP (OR 6.54 [95% CI 1.83, 23.44]) and obesity (OR 8.75 [95% 1.45, 52.73]) were associated with a positive ketamine infusion outcome.
conclusionsThe response to sympathetic blocks may predict response to ketamine infusion in CRPS patients, with alleviation of the affective component of pain and predilection to a positive placebo effect being possible explanations.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.