護理師照護一位接受環利尿劑（Loop diuretics）的心衰竭病人。護理師最擔心下列哪種電解質不平衡？
A nurse is caring for a client with a history of heart failure who is receiving loop diuretics. Which electrolyte imbalance is the nurse most concerned about?
- AHypomagnesemia低血鎂
- BHypernatremia高血鈉
- CHypercalcemia高血鈣
- DHypokalemia✓ 正解低血鉀
環利尿劑（Loop diuretics，如 Furosemide）作用於腎小管的亨利氏環（Loop of Henle），抑制鈉、氯、鉀的再吸收。長期使用會導致大量鉀離子隨尿液排出，造成低血鉀（Hypokalemia）。低血鉀對於心衰竭病人極為危險，易誘發心律不整（Arrhythmias）並增加洋地黃中毒（Digoxin toxicity）的風險。
Loop diuretics inhibit sodium and chloride reabsorption in the Loop of Henle, which significantly increases potassium excretion, making hypokalemia the most concerning electrolyte imbalance. This condition is particularly dangerous for clients with heart failure as it predisposes them to life-threatening arrhythmias and digoxin toxicity. While other electrolytes may be affected, the risk of severe cardiac complications from low potassium takes precedence in nursing assessment.