Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2000
Comparative StudyCurrent perception thresholds and postoperative pain in schizophrenic patients.
Schizophrenic patients may have less sensitivity to pain; however, pain insensitivity in schizophrenia has not been adequately evaluated. We investigated current perception threshold (CPT) and postoperative pain intensity in patients with long-standing and treated schizophrenia and control patients. ⋯ Chronic schizophrenic patients have increased current perception threshold and lower VAS pain scores in postoperative pain compared with control patients.
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Reg Anesth Pain Med · Sep 2000
Randomized Controlled Trial Clinical TrialEfficacy of oral mexiletine for neuropathic pain with allodynia: a double-blind, placebo-controlled, crossover study.
Mexiletine is an oral sodium channel antagonist that has been reported to be effective in a variety of neuropathic pain syndromes. However, recent reports question the efficacy of oral mexiletine in neuropathic pain. The objectives of this study were to examine the effect of oral mexiletine on pain, neurosensation, allodynia, and quality of life. ⋯ At doses of up to 900 mg/d, mexiletine has minimal effects on pain and allodynia of neuropathic pain. However, side effects may preclude higher doses.
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Reg Anesth Pain Med · Sep 2000
Randomized Controlled Trial Clinical TrialAlkalinized lidocaine and bupivacaine with hyaluronidase for sub-tenon's ophthalmic block.
Alkalinization of local anesthetics has been shown to decrease the onset and prolong the duration of block for extraconal and intraconal application in ocular surgery. The objective of this study is to determine if alkalinization is also effective in sub-Tenon's block when hyaluronidase is added to the drug mixture. ⋯ pH adjustment of the local anesthetic mixture of lidocaine, bupivacaine, and hyaluronidase offered no additional benefit in sub-Tenon's technique in ocular procedures.
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Reg Anesth Pain Med · Sep 2000
Alkalinization and precipitation characteristics of 0.2% ropivacaine.
Alkalinization of local anesthetics has been used to increase the speed of onset of nerve blocks. However, alkalinization of local anesthetic solutions may cause precipitation, thereby decreasing bioavailability and anesthetic activity. Alkalinization of ropivacaine has not been described. This laboratory study assessed the alkalinization and precipitation characteristics of ropivacaine. ⋯ A laboratory evaluation that establishes the alkalinization characteristics of ropivacaine is a prerequisite for designing a clinical study of alkalinized ropivacaine. In our experiment, low doses of bicarbonate produced significant increases in the proportion of nonionized ropivacaine with only modest precipitation. There would be a low likelihood of substantial drug precipitation if the mixture was administered within 5 to 10 minutes after alkalinization. These results indicate that alkalinized ropivacaine should not be used for infusions and that ropivacaine should not be alkalinized until just before use.