Articles: nerve-block.
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Long-term administration of morphine for the treatment of chronic pain produces constipation; this requires the use of laxatives, which impair water absorption and upset the electrolyte balance. Morphine-induced constipation is mainly due to inhibition of the propulsive movement of the gastrointestinal tract combined with spastic contraction of smooth circular muscles as a result of drug binding to opioid receptors in the tract. Since papaverine lacks affinity for opioid receptors but relaxes smooth muscle, it seemed possible that oral papaverine might be capable of diminishing constipation without impairing the analgesia achieved with morphine. ⋯ Since in former experiments on nociceptive activity evoked in thalamus neurones it has been found that the ED(50) of i. v. morphine is 0.05 mg/kg, it is very likely that the presystemic elimination of orally administered morphine is very high and, in addition, that the efficiency of its active metabolite, morphine-6-glucuronide, is rather poor. When morphine 2.5 mg/kg was given together with papaverine 0.5 mg/kg, and morphine 5 mg/kg was administered in combination with papaverine 2 mg/kg, there was no significant reduction in the depressant effect of morphine on nociceptive activity evoked in thalamus neurons (Figs. 6, 7). The results suggest that papaverine given by the oral route may reduce morphine-induced constipation without impairment of the analgesic action of morphine in patients suffering from pain.
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Randomized Controlled Trial Clinical Trial
Edrophonium antagonism of intense mivacurium-induced neuromuscular block in children.
We have studied the time course of recovery after administration of edrophonium during intense mivacurium block in children aged 2-10 yr, using thumb acceleration in response to train-of-four (TOF) stimulation. Forty-three children receiving alfentanil, propofol, nitrous oxide, isoflurane anaesthesia and mivacurium 0.2 mg kg-1 were allocated randomly to one of three groups. Patients in group 1 (n = 15) received edrophonium 1 mg kg-1, 2 min after maximum block (intense block group). ⋯ The recovery index (time interval between T1 25% and 75%) was comparable in groups 1-3 (5.5 (2.0), 4.8 (2.1) and 5.7 (1.4) min respectively). Ten minutes after development of maximum block, the numbers of patients who recovered adequately (TOF ratio 70% or more) were, respectively, 12 (80%), 8 (53%) and 1 (8%) in groups 1-3. We conclude that edrophonium antagonized intense (no response to TOF stimulation) mivacurium-induced block in children, with significant reduction in the recovery times of T1 and TOF ratio compared with conventional reversal and spontaneous recovery.
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We describe a new anesthetic technique of femoral and sciatic nerve blocks in knee arthroscopy. The sciatic nerve block is administered through a posterior approach, and the block of the femoral and lateral femoral cutaneous nerves in a single anterior approach. This type of regional anesthesia is safe and effective, providing excellent intraoperative and postoperative analgesia as well as minimizing postoperative complications.
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Anesthesia and analgesia · Feb 1996
Randomized Controlled Trial Comparative Study Clinical TrialCompound motor action potential recording distinguishes differential onset of motor block of the obturator nerve in response to etidocaine or bupivacaine.
The purpose of this investigation was to establish an objective (quantitative) method for determining onset time of motor block induced by different local anesthetics. Twenty-four consenting patients undergoing transurethral surgery during spinal anesthesia were randomized to receive direct obturator nerve block with 10 mL of plain bupivacaine 0.5% (n = 12) or 10 mL of plain etidocaine 1% (n = 12). Another 14 patients (control group) received obturator nerve "block" with saline. ⋯ While CMAP amplitudes in the control group returned to their initial (baseline) values after 3-6 min, the patients receiving etidocaine or bupivacaine achieved > or = 90% motor blockade after 6 and 13 min, respectively. In the present report, the time to > or = 90% block was significantly faster in patients given etidocaine compared with those given bupivacaine. We conclude that electromyographic recording of CMAPs can be used to compare the ability of different local anesthetics to induce motor block.
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Randomized Controlled Trial Clinical Trial
The effect of alkalinisation of lignocaine on axillary brachial plexus anaesthesia.
Alkalinisation of local anaesthetic drugs is a controversial technique for improving regional blockade. Forty-two patients scheduled for upper limb surgery received axillary brachial plexus anaesthesia using a cannula technique. Patients were randomly allocated to receive either lignocaine 1.5% with 1 in 200,000 adrenaline (pH = 4.2) or lignocaine 1.5% with 1 in 200,000 adrenaline (pH = 7.2). ⋯ The percentage of patients with complete anaesthesia at 10, 20 and 30 min following injection was significantly increased in the alkalinized group with regard to the ulnar and median nerves, and the median cutaneous nerve of the arm (p < 0.05). In the alkalinized group, there was a significant reduction in the time to useful anaesthesia and a reduced requirement for adjuvants (p < 0.05). There was no effect on the duration of anaesthesia.