Articles: nerve-block.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Premedication in retrobulbar anesthesia. A blood gas analysis comparison of sublingual flunitrazepam and intravenous midazolam].
Benzodiazepines for sedation may decrease the PaO2, the arterial O2 saturation (SaO2), and the CO2 response more in the elderly than in the young. The purpose of this study was to assess changes in blood gases due to i.v. midazolam or sublingual flunitrazepam given as premedication in elderly patients for unilateral cataract surgery. METHODS. ⋯ The results of the study show the potential hazards of i.v. midazolam in the elderly. If sedation is required for cataract surgery under local anaesthesia, we recommend sublingual flunitrazepam or the use of benzodiazepines with lower hypnogenic effects in the elderly. A thorough preoperative discussion of anaesthesia and the operation might be an adequate substitute for any premedication in high-risk patients; the best blood gas analysis results were obtained in the control group.
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Anesthesia and analgesia · Oct 1992
Randomized Controlled Trial Comparative Study Clinical TrialA comparative study of 0.25% ropivacaine and 0.25% bupivacaine for brachial plexus block.
The present study compares the effectiveness of 0.25% ropivacaine and 0.25% bupivacaine in 44 patients receiving a subclavian perivascular brachial plexus block for upper extremity surgery. The patients were assigned to two equal groups in this randomized, double-blind study; one group received ropivacaine 0.25% (112.5 mg) and the other, bupivacaine 0.25% (112.5 mg), both without epinephrine. Onset times for analgesia and anesthesia in each of the C-5 through T-1 brachial plexus dermatomes did not differ significantly between the two groups. ⋯ The mean duration of analgesia ranged from 9.2 to 13.0 h, and the mean duration of anesthesia ranged from 5.0 to 10.2 h. Both groups required supplementation with peripheral nerve blocks or general anesthesia in a large number of cases, with 9 of the 22 patients in the bupivacaine group and 8 of the 22 patients in the ropivacaine group requiring supplementation to allow surgery to begin. In view of the frequent need for supplementation noted with both 0.25% ropivacaine and 0.25% bupivacaine, we do not recommend using the 0.25% concentrations of these local anesthetics to provide brachial plexus block.
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Acta Anaesthesiol Scand · Oct 1992
Randomized Controlled Trial Comparative Study Clinical TrialPrilocaine in lumbosacral plexus block--general efficacy and comparison of nerve stimulation amplitude.
The significance of the threshold amperage of peripheral nerve stimulation (PNS) for the efficacy and latency of sciatic block is shown in a controlled randomized study of stimulation amplitude. In all cases the block was complete within a short time when the threshold amperage was 0.3 mA or less. Incomplete motor and sensory blocks occurred with higher stimulation amplitudes of 0.5 and 1.0 mA. ⋯ Ninety-one per cent of the combined blockades were primarily successful when there was no tourniquet at all, and 87% when the tourniquet was placed on the lower leg. In the course of surgery with a femoral pneumatic tourniquet, only 55% of the blocks did not require supplement when 20 ml of 1% prilocaine was used for the 3-in-1 block, while 72% and 74% were efficacious with 30 ml and 35 ml, respectively. The efficacy of the sciatic block proved to be extremely high (> 95%), its success depending on the dosage of the local anaesthetic and correct execution of the peripheral nerve stimulation.
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Randomized Controlled Trial Clinical Trial
Dose-response relationships for neostigmine antagonism of vecuronium-induced neuromuscular block in adults and the elderly.
We have studied the dose-response relationship for neostigmine in 36 adult (ages 18-50 yr) and 36 elderly (ages > 70 yr) subjects during antagonism of neuromuscular block induced by vecuronium. All patients received vecuronium 0.08 mg kg-1 and neuromuscular block was monitored mechanomyo-graphically using the train-of-four (TOF) mode of stimulation. Six patients of each age group were allocated randomly to receive neostigmine 5, 15, 25, 35 or 45 micrograms kg-1 or saline at 10% recovery of T1 (first response in the TOF). ⋯ There was a significant difference (P < 0.05) in the time to spontaneous recovery of T1 to 10% between the adults (24 (SD 5.5) min) and the elderly (33 (7.8) min). Dose-response curves for neostigmine were parallel in the two age groups, but those for the elderly were significantly to the right of the curves for the adults. This suggests an apparently lesser relative potency of neostigmine, or the requirement of a larger dose, in the elderly for attaining antagonism of a moderately intense vecuronium block at the same time as in adults.
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Randomized Controlled Trial Clinical Trial
[The effect of adding clonidine to mepivacaine. Axillary brachial plexus blockade].
Clonidine (Cl) added to local anaesthetics (LA) prolongs the duration of both anaesthesia and analgesia after peripheral nerve blocks. In this study, we investigated the dose-dependent effect of Cl added to mepivacaine (M) on clinical efficacy, onset, and regression time of brachial plexus block. METHODS. ⋯ Neither the onset time nor the number of patients with adequate surgical anaesthesia was influenced by Cl. Considering the M plasma levels, it is unlikely that the prolongation of the block is caused by local vasoconstriction, which is proposed to be the mechanism of action of epinephrine. The mean differences in haemodynamic parameters were not of clinical relevance, but the two dramatic drops in BP and HR, probably caused by Cl, were significant.