When we perform the regional blockade, we usually addit epinephrine to the local anesthetics for the purpose of lengthening anesthesia time and preventing the systemic reaction of local anesthetics. In that situation. Epinephrine produces
decrease
in
serum potassium concentration and changes in electrocardiogram
We investigated the influence of propranolol on changes in serum potassium and ECC induced by brachial plexus block with 30ml of mixture of local anestheti(2% lidocaine -0.5% bupivacain) which contains 1:200,000 epinephrine.
@ES The subjects classified as foll0wing two groups:
@EN Group I: Erachial plexus block with mixture of local anesthetic and 1: 200,000 epinephrine(n=20).
Group Ⅱ: Pretreated with 2 mg of propranolol(slow intravenous injection for 5 min before block) and performed as Group Ⅰ.
@ES The results were as follows:
@EN 1) Group I Showed statistically significant decrease of earum potassium after 10. 20, 30 min, of block(p<0.05), Group Ⅱdid not show any significant change.
2) Group I showed progressive flattening of T wave and appearance of U wave(25% of pts) in ECG as the serum-potassium decreased progressively, but Group Ⅱdid not show any significant change.
3) The epinephrine mediated beta-adrenergic stimulation may be considered as the cause of epinephrine induced hypokalemia during brachial plexus block.
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