Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Nov 2001
Randomized Controlled Trial Comparative Study Clinical TrialClonidine versus ketamine to prevent tourniquet pain during intravenous regional anesthesia with lidocaine.
Both clonidine and ketamine have been found to prolong the action of local anesthetics through a peripheral mechanism. Our study compares the efficacy of a low dose of clonidine or ketamine separately added to intravenous regional anesthesia (IVRA) with lidocaine to prevent tourniquet pain. ⋯ The addition of clonidine 1 microg/kg or ketamine 0.1 mg/kg to lidocaine for IVRA delays the onset of unbearable tourniquet pain and decreases analgesic consumption for tourniquet pain relief, although ketamine has a more potent effect.
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Reg Anesth Pain Med · Nov 2001
Randomized Controlled Trial Clinical TrialEffects of epidural anesthesia on thermal sensation.
Epidural anesthesia decreases the core temperatures triggering vasoconstriction and shivering, presumably by increasing apparent (as opposed to actual) lower-body temperature. We therefore tested the hypothesis that epidural anesthesia also increases the overall perception of warmth. ⋯ Thermal sensation with and without epidural anesthesia was comparable at a lower-body temperature near 34 degrees C, which is a normal leg skin temperature. This suggests that autonomic and behavioral thermoregulatory consequences of epidural anesthesia differ-or that the current explanation for reduced vasoconstriction and shivering thresholds during epidural anesthesia is incorrect.
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Reg Anesth Pain Med · Nov 2001
Randomized Controlled Trial Clinical TrialEpidural fentanyl speeds the onset of sensory block during epidural lidocaine anesthesia.
Shortening the onset time of sensory block is a practical goal to improve the quality of epidural anesthesia. The addition of fentanyl to a local anesthetic solution is widely used during epidural anesthesia. This randomized double-blind study examined the onset time of sensory block during epidural lidocaine anesthesia with and without added fentanyl to the epidural solution. ⋯ Epidural injection of the mixture of 100 microg fentanyl and 2% lidocaine solution accelerated the onset of sensory block during epidural lidocaine anesthesia without increased side effects.
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Reg Anesth Pain Med · Nov 2001
Randomized Controlled Trial Clinical TrialA paravenous approach for the saphenous nerve block.
This study assesses a paravenous approach for saphenous nerve block at approximately the level of the tibial tuberosity, and compares it with the conventional technique of blind subcutaneous infiltration between the tibial tuberosity and the gastrocnemius muscle. ⋯ The saphenous nerve can be blocked effectively by a paravenous approach using only 5 mL of local anesthetic solution. This approach is advantageous because of its easily identifiable landmark.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialEffect of impulse duration on patients' perception of electrical stimulation and block effectiveness during axillary block in unsedated ambulatory patients.
Chronaxie of the motor-neurons (A-alpha) is shorter than that of the sensory A-delta and C neurons. Therefore, a short current impulse should elicit a painless muscle twitch. This randomized, double-blind study of patients having ambulatory axillary block by multiple neurostimulations compared patients' perception of electrical stimulation, latency, and quality of analgesia and the incidence of adverse effects. ⋯ This study did not confirm our hypothesis that short-current impulses (0.1 ms) make neurostimulation of peripheral nerves painless, by selectively depolarizing motor-neurons. Longer impulses (0.3 ms) shorten block performance time, probably by easier location of the nerves, but the clinical relevance of this finding is doubtful.