Regional-Anaesthesie
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Regional-Anaesthesie · Jan 1988
Comparative Study[Comparison of bupivacaine hydrochloride 0.5% and bupivacaine carbonate 0.5% in interscalene plexus anesthesia].
Carbonated local anesthetics are less acidic than the hydrochlorides and require less buffering by the tissues. Rapid buffering and diffusion of the carbon dioxide enables free base to be deposited in high concentrations on nerve fibres. Carbon dioxide increases the intracellular hydrogen ion concentration, thus increasing the amount of active cation at the receptor site. ⋯ The first analgesia was detected by pinprick 5.1 +/- 0.4 (SE) min and complete analgesia in 19 +/- 1 min after bupivacaine hydrochloride and 4.7 +/- 0.5 min and 15 +/- 1 min after bupivacaine carbonate. The more caudad nerves showed a significantly longer latency time than the more cephalad ones. The duration of sensory analgesia varied between 6 and 12 hours, the more caudad nerves showing the shortest duration.(ABSTRACT TRUNCATED AT 250 WORDS)
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Regional-Anaesthesie · Oct 1987
Case Reports[Lumbar epidural hematoma and spinal abscess following peridural anesthesia].
Epidural application of local anesthetics or opiates is commonly used for treatment of severe pain or arterial obstruction. We discuss two cases of complications following peridural anesthesia. As an acute complication, a lumbar epidural hematoma developed hours after placement of the catheter and caused sciatic pain and nearly complete paraplegia. ⋯ The risk of infectious complications after long-term peridural catheterization may be up to 20%. Hematogenous metastatic infection is more common in patients with malignancies or multiple risk factors than continuous immigration of bacteria. Epidural hematomas and spinal abscesses can cause disability and persistent neurological deficit in spite of aggressive surgical and antibiotic therapy.
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For decades it has been known that the combined sciatic and femoral nerve block could be used for operations on the leg. Nevertheless, it is used in very few hospitals as a routine method for surgical anesthesia and only few publications exist in this area. To highlight some practical aspects, we have produced a retrospective study of 660 cases of femoral and sciatic nerve blocks used exclusively for operating purposes. ⋯ The most important factor influencing the failure rate was the anesthesiologist. The individual failure rate of the first 30 blocks of each anesthesiologist (V30) was nearly equal to the overall individual failure rate (Fig. 3). The form and time of premedication and the extent of sedation did not influence the results.(ABSTRACT TRUNCATED AT 250 WORDS)
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Regional-Anaesthesie · Oct 1987
[Effect of dihydroergotamine (DHE) on blood volume and circulation in the calf in peridural anesthesia in the human].
Dihydroergotamine (DHE) preferentially constricts capacitance vessels in the skin and striated musculature, thereby redistributing blood in favor of the pulmonary vascular bed in the presence of neurogenic vascular tone. The aim of this study was to see if DHE would act likewise when neurogenic vascular tone is absent. Filling and blood flow of the calves were measured plethysmographically in six healthy, supine male volunteers before and during peridural anesthesia (PDA) to the level of at least T5 and, in the denervated state, after the injection of DHE 7.5 micrograms/kg intravenously. ⋯ In the absence much as in the presence of neurogenic vascular tone, DHE preferentially constricts capacitance but not resistance vessels. Thus, DHE counteracts the vascular effects of PDA, as it improves cardiac filling and consequently raises arterial blood pressure by redistributing blood from the dilated capacitance vessels without curtailing blood flow. It would appear, therefore, that DHE is a rational alternative to fluid therapy for the prophylaxis of arterial hypotension during major conduction anesthesia.
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Regional-Anaesthesie · Jul 1987
Comparative Study[Comparative study of circulatory and ECG-changes after supraclavicular plexus block with bupivacaine-HCl 0.5 per cent in patients with chronic kidney failure].
The systemic effects of local anesthetic drugs, especially bupivacaine, on myocardial conduction and the increase of cardiotoxicity by hypoxemia, acidosis, and hyperkalemia has been proven in numerous animal experiments. In our department, supraclavicular brachial block with bupivacaine is the method of choice for patients with chronic renal failure requiring operations of the upper limb. The question may be raised whether or not these patients with their concomitant disease--electrolyte and acid-base imbalances, uremic cardiomyopathy--are especially endangered by the use of this drug. ⋯ Comparing the two groups, no severe changes in electrolytes or acid-base status could be found despite some statistical significances. Even though bupivacaine serum concentrations proved to be 3 times higher in the study group than in the control group, no changes in cardiac conduction could be registered. We conclude that bupivacaine is as safe in dialyzed patients with chronic renal failure with regard to possible changes in circulatory parameters and myocardial conduction as in healthy patients.(ABSTRACT TRUNCATED AT 250 WORDS)