Löfgren A, Hahn R G
Department of Anesthesiology, Huddinge University Hospital, Sweden.
Reg Anesth. 1994 Jul-Aug;19(4):247-54.
Hypokalemia may arise from adrenergic stimulation during regional anesthesia. The authors studied the effects of adding epinephrine to the local anesthetic solution and of upper abdominal surgery on the hypokalemia following intercostal nerve block.
Intercostal block was induced with bupivacaine 0.5% in 10 female volunteers. Bupivacaine 0.5% with epinephrine 1:200,000 was used for another intercostal nerve block in the same volunteers and in eight women who had just undergone cholecystectomy. Plasma concentrations of potassium, epinephrine, glucose, and bupivacaine were measured and the ECG was recorded.
The decrease in the plasma potassium level during the experiment with plain bupivacaine was 0.10 +/- 0.09 mmol/L (mean +/- SEM). With bupivacaine and epinephrine, the decrease was 0.26 +/- 0.06 mmol/L in the volunteers and 0.58 +/- 0.07 mmol/L in the patients. After surgery the drug absorption was facilitated and the concentration-response relationship between epinephrine and potassium was maintained. The epinephrine-containing local anesthetic was associated with minor ECG changes.
The hypokalemic effect of intercostal nerve block with bupivacaine 0.5% and epinephrine 1:200,000 is doubled after upper abdominal surgery performed under general anesthesia.
区域麻醉期间，肾上腺素能刺激可能导致低钾血症。作者研究了在局部麻醉溶液中添加肾上腺素以及上腹部手术对肋间神经阻滞后低钾血症的影响。
对10名女性志愿者使用0.5%布比卡因进行肋间阻滞。在同组志愿者以及8名刚接受胆囊切除术的女性中，使用含1:200,000肾上腺素的0.5%布比卡因进行另一次肋间神经阻滞。测量血浆钾、肾上腺素、葡萄糖和布比卡因的浓度，并记录心电图。
使用单纯布比卡因进行实验期间，血浆钾水平下降0.10±0.09 mmol/L（均值±标准误）。使用布比卡因和肾上腺素时，志愿者血浆钾水平下降0.26±0.06 mmol/L，患者下降0.58±0.07 mmol/L。术后药物吸收加快，肾上腺素与钾之间的浓度 - 反应关系得以维持。含肾上腺素的局部麻醉药与轻微的心电图变化有关。
在全身麻醉下进行上腹部手术后，使用含1:200,000肾上腺素的0.5%布比卡因进行肋间神经阻滞的低钾效应加倍。
