Articles: anesthetics.
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Low back pain and sciatica have been treated with peridural local anesthetics for over 80 years and with epidural and subarachnoid steroid injections for a quarter of a century. This review surveyed the literature concerning the evolution, pathophysiology, complications and results of this type of therapy. The volume injected and the method used vary with different physicians and no standard has been established. ⋯ It is the authors' opinion that the rationale for the use of spinal local analgesics or steroids or intramuscular steroids has not been scientifically proven. Complications with the use of subarachnoid steroids are sufficiently serious that this form of therapy should be condemned. In this age of accountability it is imperative that therapies with questionable benefits should be critically evaluated.
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Acta Anaesthesiol Scand · May 1985
Effects of adjuvants to local anaesthetics on their duration. I. Studies of dextrans of widely varying molecular weight and adrenaline in rat infraorbital nerve block.
Local anaesthetics of the amide type were studied in a modified rat infraorbital nerve block model, with which it was possible to determine varying degrees of sensory block. Of the agents investigated, 0.5% bupivacaine tended to give a longer duration of block than 2% prilocaine or 2% lidocaine, while 0.5% etidocaine had the shortest duration. The duration of prilocaine was prolonged by addition of adrenaline, 5 micrograms/ml, more than that of the other agents. ⋯ The extent of prolongation was dependent on the degree of block, the concentration of dextrans in the local anaesthetic solution, and the Mw of the dextran although in a less uniform way. An increase in the relative viscosity of the solutions might be a factor of importance for the prolonging effect of addition of dextran to local anaesthetics. Since a formulation providing analgesia of a long duration would be of clinical value, further studies on combinations of the comparatively low-toxicity agent prilocaine and macromolecular substances are of interest.
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Randomized Controlled Trial Clinical Trial
Effects of the extradural administration of local anaesthetic agents and morphine on the urinary excretion of cortisol, catecholamines and nitrogen following abdominal surgery.
Twenty patients undergoing major abdominal surgery were allocated randomly to receive either general anaesthesia with low-dose fentanyl plus intermittent systemic morphine for postoperative pain or the same general anaesthetic plus extradural analgesia during and following surgery (local anaesthetics from before skin incision until 24 h after skin incision plus extradural morphine 4 mg every 12 h from 3 h to 72 h after skin incision). Postoperative pain scores were lower (P less than 0.05) in the group receiving extradural analgesia, but this regimen failed to prevent the increase in the urinary excretion of cortisol, adrenaline, noradrenaline and nitrogen both on separate days and on cumulative measurements over 4 days. Pain scores did not correlate to urinary excretion of the various endocrine-metabolic indices either on separate days or over the cumulative 4-day period. It is concluded that the relief of pain per se has no major influence on the catabolic response to abdominal surgery.
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Neurotoxicity after subarachnoid infusion of bupivacaine, lignocaine and 2-chloroprocaine was studied in a chronic rat model. Hartmann's solution 100 microliter h-1 was infused as a control, and 0.5% bupivacaine, 1.5% lignocaine and 2.0% 2-chloroprocaine were infused at 100 microliter h-1 for 3, 6 or 24 h, to five rats in each group. ⋯ Abnormal histology, in the form of neuronal vacuolation, was not a sensitive index, being present in control rats, but more intense in those receiving lignocaine and 2-chloroprocaine than in those given bupivacaine; no correlation with clinical findings could be established. The neurotoxic effects of each local anaesthetic tested as a continuous intrathecal infusion were dose related in the rat, which may be a useful model for screening other local anaesthetics.
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Acta Anaesthesiol Scand · Apr 1985
Randomized Controlled Trial Comparative Study Clinical TrialIsoflurane v fentanyl for outpatient laparoscopy.
Isoflurane and fentanyl have been compared as anaesthetic agents for outpatient laparoscopy. In 50 female patients anaesthesia was induced with thiopentone and maintained with nitrous oxide 66% in oxygen combined with either isoflurane 1-2% or fentanyl 0.3 mg according to a randomized list. Suxamethonium was used to facilitate intubation and for further muscle relaxation. ⋯ Reaction times in the isoflurane patients returned to control by 3 h, whereas the fentanyl patients were 10% slower than control at 4 h (P less than 0.05 at 2 h, 3 h, 4 h). Nausea and vomiting were more frequent in the fentanyl group, and four of the fentanyl patients required naloxone. Both anaesthetic techniques provided satisfactory operating conditions, but isoflurane appeared to provide a better recovery with less side effects than fentanyl.