Regional-Anaesthesie
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Regional-Anaesthesie · Jan 1990
Biography Historical Article[Georg Perthes--a pioneer of modern regional anesthesia technics?].
In regional anesthesia, the localization of peripheral nerves and plexuses is possible by means of mechanical or electrical stimulation. Electrical stimulation for this purpose was first described in 1912 by the surgeon Georg Perthes (1869-1927) of Tübingen, who reported his own experiences. The original description and results of electrostimulation are transposed upon a modern point of view of regional anesthesia.
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Regional-Anaesthesie · Jan 1990
[Elimination of the obturator reflex as a specific indication for dilute solutions of etidocaine. A study of the suitability of a local anesthetic for reflex elimination in the 3-in-1 block technic].
Direct stimulation of the obturator nerve by the electroresectoscope during transurethral resection of tumors in lateral bladder regions is possible under regional or general anaesthesia without muscle relaxation. The resulting obturator reflex may lead to perforation of the bladder. Two different regional techniques can be used to interrupt the obturator reflex arc: (1) separate block of the obturator nerve; or (2) the "3-in-1 block" (Winnie). ⋯ Elimination of the obturator reflex is the only specific motor nerve block in anesthesia. Diluted etidocaine solutions seem to be adequate: irrespective the technique used for eliminating the reflex, diluted etidocaine produces a good effect and permits a dosage reduction compared with other local anesthetics. It is possible to block the obturator nerve bilaterally by "3-in-1 block" or unilaterally by "3-in-1 block" in combination with epidural analgesia within the recommended dose limits.
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Regional-Anaesthesie · Jan 1990
[The significance of the sampling site in the determination of plasma levels of local anesthetics using 0.75% bupivacaine as an example].
Knowledge of the actual concentrations of local anesthetic administered by various techniques is essential requisite when undesirable side effects and possible toxicity of a substance are to be evaluated. Therefore, numerous studies of plasma concentrations have been presented, which were carried out with the additional purpose of analyzing the kinetics of different local anesthetics with respect to limiting-value concentrations in the organism. Despite a sufficient degree of precision in the analysis of amide local anesthetics, it is uncertain whether the results of the different studies are comparable, because blood samples have been taken variously from peripheral veins, central veins or arteries. ⋯ The observed uniform differences in concentrations at the various sites of sampling can be explained by the fact that pulmonary uptake of local anesthetics causes the lower arterial levels. Especially in the early phase of resorption after administration of local anesthetics, the concentration in peripheral blood does not seem to be representative, because an equilibrium is not established between arterial and central venous blood until 30 min after administration at the earliest. In our opinion the peripheral venous concentrations are unreliable, particularly in the early phases, for the evaluation of unwanted effects or toxicity of local anesthetics, because the initial low values and the delayed increase in these could lead to a false sense of security.
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Regional-Anaesthesie · Jan 1990
[Experimental studies on peripheral nerve injuries caused by injection needles].
Differences in neural damage due to different injection needles were investigated in vitro on sciatic nerve specimens of adult rabbits. METHODS. Three types of 22-gauge needles were tested: one typical, long-bevelled venous puncture needle; a short bevelled, typical nerve block needle; and a tapered, atraumatic spinal needle. ⋯ Fluorescence microscopy. With the tapered injection needle there was the least leakage of EBA, which suggests the least damage to the perineurium, and almost no rupture or tearing of the nerve fibers was observed. In the short- and long-bevelled needles, the damage was reduced when the face of the bevel was inserted parallel to the fibers.