Articles: pain-clinics.
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Human studies have demonstrated a correlation between noncoding polymorphisms of "the pain protective" haplotype in the GCH1 gene that encodes for GTP cyclohydrolase I (GTPCH1)-which leads to reduced tetrahydrobiopterin (BH4) production in cell systems-and a diminished perception of experimental and clinical pain. Here, we investigate whether heterozygous mutations in the GCH1 gene which lead to a profound BH4 reduction in patients with dopa-responsive dystonia (DRD) have any effect on pain sensitivity. The study includes an investigation of GCH1-associated biomarkers and pain sensitivity in a cohort of 22 patients with DRD and 36 controls. ⋯ The patients with DRD were heterozygous for the pain protective haplotype in cis with the GCH1 disease-causing mutation, c.899T>C. No effect on pain perception was observed for this combined haplotype. In conclusion, a reduced concentration of BH4 is not sufficient to alter ongoing pain sensitivity or evoked pain responses.
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Anesthesia and analgesia · Jun 2018
Randomized Controlled Trial Comparative StudyAdductor Canal Block With Continuous Infusion Versus Intermittent Boluses and Morphine Consumption: A Randomized, Blinded, Controlled Clinical Trial.
Based on the assumption that relatively large volumes of local anesthetic optimize an adductor canal block (ACB), we theorized that an ACB administered as repeated boluses would improve analgesia without compromising mobility, compared with a continuous infusion. ⋯ Changing the mode of administration for an ACB from continuous infusion to repeated intermittent boluses did not decrease opioid consumption, pain, nor mobility.
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As an indirect approach to relate previously identified sensory phenotypes of patients suffering from peripheral neuropathic pain to underlying mechanisms, we used a published sorting algorithm to estimate the prevalence of denervation, peripheral and central sensitization in 657 healthy subjects undergoing experimental models of nerve block (NB) (compression block and topical lidocaine), primary hyperalgesia (PH) (sunburn and topical capsaicin), or secondary hyperalgesia (intradermal capsaicin and electrical high-frequency stimulation), and in 902 patients suffering from neuropathic pain. Some of the data have been previously published. Randomized split-half analysis verified a good concordance with a priori mechanistic sensory profile assignment in the training (79%, Cohen κ = 0.54, n = 265) and the test set (81%, Cohen κ = 0.56, n = 279). ⋯ Topical menthol was the only model with significant cold hyperalgesia. Sorting of the 902 patients into these mechanistic phenotypes led to a similar distribution as the original heuristic clustering (65% identity, Cohen κ = 0.44), but the denervation phenotype was more frequent than in heuristic clustering. These data suggest that sorting according to human surrogate models may be useful for mechanism-based stratification of neuropathic pain patients for future clinical trials, as encouraged by the European Medicines Agency.
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Accurate pain assessment and management constitute a major challenge for medical and nursing staff in intensive care units (ICUs). A distinct recollection of pain is reported by high proportions of ICU patients. ⋯ Appropriately trained ICU nurses have the potential to help adopt pain relief and prevention measures during nursing care and to contribute to the successful management of sedation and analgesia. Further studies of larger patient samples are needed to monitor the stability of results over time and to explore the efficacy of the approach in other populations, such as pediatric and neonatal ICU patients.
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Pain is a major complication for patients with cancer significantly compromising their quality of life. Current treatment is far from optimal and particularly bone-related cancer pain poses an increasing clinical and socioeconomical problem. Connexins, key proteins in cell-cell communication, have the potential to affect cancer-induced bone pain at multiple levels, including nociceptive signaling and bone degradation. ⋯ Carbenoxolone treatment had a minor effect on the bone degradation in the early phase of disease progression, whereas no effect was observed in the late phase. Surprisingly, connexin43 was downregulated in the cancer-bearing animals compared with shams. The results suggest that connexins are involved in cancer-induced bone pain, and that carbenoxolone could be a novel analgesic treatment for the pain state.