Regional anesthesia and pain medicine
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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.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialSuccess rate of unilateral spinal anesthesia is dependent on injection flow.
The dependence of unilateral spinal anesthesia on injection flow is controversial. We hypothesized that it is possible to achieve strictly unilateral sympathetic block (as assessed by temperature measurements of the limbs) and unilateral sensory and motor block, respectively, during spinal anesthesia by a slow and steady injection of a hyperbaric local anesthetic solution. ⋯ For hyperbaric spinal anesthesia, the injection flow is an important factor in achieving unilateral sympathetic block. A slow injection proves useful to restrict spinal anesthesia to the side of surgery.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialAddition of fentanyl to bupivacaine prolongs anesthesia and analgesia in axillary brachial plexus block.
To evaluate the analgesic and anesthetic effects of 40 mL bupivacaine 0.25%, 40 mL bupivacaine 0.25% plus fentanyl 2.5 microg/mL, and 40 mL bupivacaine 0.125% plus fentanyl 2.5 microg/mL for axillary brachial plexus block. ⋯ The addition of 100 microg/mL fentanyl to 0.25% bupivacaine almost doubles the duration of analgesia following axillary brachial plexus block when compared with 0.25% bupivacaine alone.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialEffect of systemic adenosine on pain and secondary hyperalgesia associated with the heat/capsaicin sensitization model in healthy volunteers.
Adenosine is an endogenous compound that may have analgesic effects. Results from clinical trials are not consistent, however, and there is a need for large-scale, randomized, placebo-controlled studies to clarify the role of adenosine in the treatment of pain states, including acute nociceptive pain and pain involving central sensitization. ⋯ We conclude that adenosine has no effect on acute nociceptive pain induced by heat stimulation or on secondary hyperalgesia induced by heat/capsaicin sensitization in healthy volunteers.
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Reg Anesth Pain Med · Sep 2001
Randomized Controlled Trial Clinical TrialIntrathecal labor analgesia with bupivacaine and sufentanil: the effect of adding 2.25 microg epinephrine.
Epinephrine, 25 microg and 200 microg, has been found to prolong the duration of intrathecal labor analgesia when added to an opioid. In our hospital we use the standard epidural mixture, prepared by the pharmacist, containing epinephrine 1:800,000; i.e., 1.25 microg/mL for both spinal and epidural labor analgesia. We wanted to evaluate whether such a low dose, depending on its effect on duration or quality of analgesia, should be maintained or deleted in future mixtures. ⋯ It was concluded that epinephrine in a dose as low as 2.25 microg significantly prolonged the duration of intrathecal analgesia of bupivacaine-sufentanil by 15 minutes. No other differences were noticed. Diluting the commercially available bupivacaine 0.5% with epinephrine 1:200,000 may avoid the need of freshly prepared epinephrine solutions.