Pain medicine : the official journal of the American Academy of Pain Medicine
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Acute pain management in opioid-dependent persons is complicated because of tolerance and opioid-induced hyperalgesia. Very high doses of morphine are ineffective in overcoming opioid-induced hyperalgesia and providing antinociception to methadone-maintained patients in an experimental setting. Whether the same occurs in buprenorphine-maintained subjects is unknown. ⋯ Buprenorphine subjects, compared with controls, were hyperalgesic (cold pressor test), did not experience antinociception, despite high plasma morphine concentrations, and experienced respiratory depression. Clinical implications are discussed.
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Long head biceps tendon peritendinous or sheath injections are routinely administered at or immediately distally to the bicipital groove. The main indication for injection remains the clinical diagnosis or treatment of biceps tendinopathy, although true inflammation of the tendon within the bicipital groove is rare. Because the tendon sheath is merely an extension of the joint cavity, it is plausible to assume that an injection into the sheath would result in intraarticular spread. Surprisingly, such an anatomical tenet has a vague confirmation in the published clinical literature. This experiment was undertaken to investigate patterns of injectate spread when peri-tendon injection at the bicipital groove is performed. ⋯ The experiment confirmed continuity of the joint capsule and the biceps tendon sheath. These results suggest a low diagnostic utility of peritendinous injections at the level of the bicep groove. Such injections would likely result in intraarticular deposit of the injectate. Nonetheless, this approach may be utilized as an alternative simplified access to the glenohumeral joint.
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Chronic low back pain (CLBP) is usually quantified using the visual analog scale (VAS). However, the VAS is a subjective measure and prone to reporting bias, therefore making it difficult to differentiate patients with true pain from those seeking to obtain secondary gain. This study aimed to evaluate the feasibility of using plasma β-endorphin as an objective biomarker for CLBP. ⋯ A change in plasma β-endorphin level may be a surrogate marker of the treatment response for patients with CLBP. Advancements in β-endorphin measurements may help us better quantify pain intensity.