一位低血鉀病人。護理師應優先進行哪項評估？

低血鉀症會影響細胞膜的電位穩定，特別是對心肌細胞的電生理影響最為顯著。臨床上，低血鉀容易引發心電圖變化（如 U 波出現、T 波平坦、ST 段下降），並增加室性心律不整（如心室頻脈）的風險。雖然低血鉀也會導致肌肉無力、腸蠕動變慢（腸音變弱）或意識改變，但心律不整直接威脅生命，因此心電圖監測與心律評估是護理師處理低血鉀時的最高優先級。

Hypokalemia disrupts cell-membrane potential stability and has its most pronounced electrophysiologic effect on cardiac cells. Clinically, hypokalemia can cause ECG changes (such as U waves, flattened T waves, and ST-segment depression) and increases the risk of ventricular dysrhythmias such as ventricular tachycardia. Although hypokalemia can also cause muscle weakness, decreased bowel motility (hypoactive bowel sounds), or altered mental status, dysrhythmias pose a direct threat to life, so ECG monitoring and rhythm assessment are the highest nursing priorities in managing hypokalemia.