一位病人服用 furosemide 控制高血壓，護理師評估時應優先關注哪種電解質不平衡？

Furosemide（Lasix）作為環利尿劑，其作用機制是抑制亨利氏環對電解質的再吸收，這會導致鉀離子隨尿液大量流失。低血鉀（Hypokalemia）是使用此藥最常見且嚴重的副作用，可能引發致命性心律不整。雖然其他電解質（如鈉、鈣、鎂）也可能受到影響，但鉀離子對心肌電位的影響最為直接且致命，故低血鉀是護理評估的最優先重點。

Furosemide is a loop diuretic that inhibits sodium and chloride reabsorption in the loop of Henle, also causing significant potassium loss in the urine. Hypokalemia is the most common and dangerous adverse effect, potentially causing fatal arrhythmias. Although sodium, calcium, and magnesium are also affected, potassium has the most immediate and lethal cardiac impact.