[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. Supraclavicular brachial blockade (3 mg/kg bupivacaine 0.5% + 0.1 IU vasopressin/ml) was performed in 10 patients with chronic renal failure requiring hemodialysis. The control group consisted of 10 healthy patients who were admitted for minor hand surgery. Preoperative blood samples were taken for measurements of blood urea nitrogen, serum creatinine, serum electrolytes, and arterial blood gas analysis. Long-term ECG monitoring begun 20 min before injection of the block and continued over a total of 200 min. Serum concentrations of bupivacaine were determined at 10, 20, 30, 60, 120, and 180 min after injection. 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)