Articles: nerve-block.
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Sixteen patients suffering from rheumatoid or osteoarthritis of the shoulder joint were studied. All patients complained of pain and limitation of active movement of the shoulder joint. Combined neural blockade of the suprascapular nerve (SSNB) and articular branches of the circumflex nerve (ACNB) was carried out using 4 mL of 1% prilocaine and 4 mL of 6% aqueous phenol. ⋯ These findings were significant (P < 0.05). Further clinical evaluation of combined SSNB and ACNB in relation to previously reported methods of neural blockade of the shoulder joint is warranted using a randomized, controlled, comparative study. Conventional power calculations (80% power, 5% test) indicate that 17 patients per group would be necessary to detect one standard deviation (about 2 VASP) or 64 per group to detect a change of 0.5 standard deviations.
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The sphenopalatine ganglion and its involvement in the pathogenesis of pain has been the subject of debate for the last 90 years. The ganglion is a complex neural center composed of sensory, motor, and autonomic nerves, which makes it difficult to determine its pathophysiology. ⋯ The techniques for blockade range from superficial to highly invasive. Efficacy studies, though few and small, show promise in patients who have failed pharmacologic or surgical therapies.
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Clinical Trial
Greater occipital nerve blockade in cervicogenic headache.
Cervicocogenic headache (CeH) is a relatively common disorder. Although on ideal treatment is available so far, blockades in different structures and nerves may be temporarily effective. ⋯ The improvement is less marked during the first two days, a phenomenon we called "tilde pattern". GON blockades may reduce the pool of exaggerated sensory input and antagonize a putative "wind-up-like effect" which may explain the headache improvement.
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Anesthesia and analgesia · Dec 1998
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of 0.5% bupivacaine, 0.5% ropivacaine, and 0.75% ropivacaine for interscalene brachial plexus block.
The onset time and duration of action of ropivacaine during an interscalene block are not known. The potentially improved safety profile of ropivacaine may allow the use of higher concentrations to try and speed onset time. We compared bupivacaine and ropivacaine to determine the optimal long-acting local anesthetic and concentration for interscalene brachial plexus block. Seventy-five adult patients scheduled for outpatient shoulder surgery under interscalene block were entered into this double-blind, randomized study. Patients were assigned (n = 25 per group) to receive an interscalene block using 30 mL of 0.5% bupivacaine, 0.5% ropivacaine, or 0.75% ropivacaine. All solutions contained fresh epinephrine in a 1:400,000 concentration. At 1-min intervals after local anesthetic injection, patients were assessed to determine loss of shoulder abduction and loss of pinprick in the C5-6 dermatomes. Before discharge, patients were asked to document the time of first oral narcotic use, when incisional discomfort began, and when full sensation returned to the shoulder. The mean onset time of both motor and sensory blockade was <6 min in all groups. Duration of sensory blockade was similar in all groups as defined by the three recovery measures. We conclude that there is no clinically important difference in times to onset and recovery of interscalene block for bupivacaine 0.5%, ropivacaine 0.5%, and ropivacaine 0.75% when injected in equal volumes. ⋯ In this study, we demonstrated a similar efficacy between equal concentrations of ropivacaine and bupivacaine. In addition, increasing the concentration of ropivacaine from 0.5% to 0.75% fails to improve the onset or duration of interscalene brachial plexus block.
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Anesthesia and analgesia · Dec 1998
Randomized Controlled Trial Clinical TrialThe use of metoprolol and glycopyrrolate to prevent hypotensive/bradycardic events during shoulder arthroscopy in the sitting position under interscalene block.
Sudden profound hypotensive and/or bradycardic events (HBE) have been reported in >20% of patients undergoing shoulder arthroscopy in the sitting position under interscalene block anesthesia. Retrospective studies suggest that the administration of beta-blockers is safe and may decrease the incidence of these episodes. We performed a randomized, prospective study to evaluate prophylaxis of these events. One hundred fifty patients were randomized to one of three groups (placebo; prophylactic metoprolol to achieve a heart rate <60 bpm or a maximal dose of 10 mg; or prophylactic glycopyrrolate to achieve a heart rate >100 bpm or a maximal dose of 6 microg/kg) immediately after the administration of the interscalene block. Blood pressure control was achieved with IV enalaprilat as needed. The incidence of HBE was 28% in the placebo group versus 5% in the metoprolol group (P = 0.004). The rate of 22% in the glycopyrrolate group was not significantly different from placebo. Preoperative heart rate and arterial blood pressure, intraoperative sedation score, IV fluids, and enalaprilat use were similar in those patients who had a HBE compared with those who did not. Many aspects of this clinical setting are similar to tilttable testing for patients with recurrent vasovagal syncope, in which beta-adrenergic blockade with metoprolol has also been shown to be effective. We conclude that the Bezold-Jarisch reflex is the most likely mechanism for these events. ⋯ Episodes of acute hypotension and bradycardia occur during shoulder arthroscopy in the sitting position under interscalene block. In this study, we demonstrate that metoprolol, but not glycopyrrolate, markedly decreases the incidence of these episodes when given prophylactically immediately after the administration of the block.