一位低血鉀病人正在接受靜脈輸注氯化鉀。下列何者是護理師評估的優先重點？

低血鉀（Hypokalemia）是指血液中鉀離子（Potassium ion）濃度過低。鉀離子在維持細胞膜電位穩定，特別是心肌細胞和神經肌肉細胞的正常功能方面扮演著關鍵角色。當血鉀過低時，會影響心肌細胞的去極化（depolarization）和再極化（repolarization）過程，導致心臟電氣傳導異常，增加發生各種心律不整（cardiac arrhythmias）的風險，其中一些可能是致命的，例如心室頻脈（ventricular tachycardia）或心室纖維顫動（ventricular fibrillation）。因此，在給予低血鉀病人靜脈輸注氯化鉀（Potassium chloride, KCl）時，監測心臟的電氣活動，特別是心電圖（electrocardiogram, ECG）或心臟監護儀（cardiac monitor）上的變化，是護理師評估的最高優先級（highest priority）。 雖然低血鉀也會引起肌肉痙攣（muscle cramps）、便秘（constipation，表現為腸鳴音減弱）、以及 IV 插入部位疼痛（pain at the IV insertion site，可能與 KCl 輸注刺激有關），但這些臨床表現的緊急程度和潛在危險性，遠不及發生危及生命的心律不整。ABC 原則（Airway, Breathing, Circulation）中，心臟功能直接關係到循環（Circulation）的穩定，因此心律的監測具有最高優先級。

Hypokalemia refers to a low serum potassium concentration. Potassium plays a key role in maintaining cell membrane potential, particularly in the normal function of cardiac muscle cells and neuromuscular cells. When serum potassium is too low, it affects the depolarization and repolarization of cardiac cells, leading to abnormal cardiac electrical conduction and increasing the risk of various cardiac arrhythmias, some of which may be lethal, such as ventricular tachycardia or ventricular fibrillation. Therefore, when administering IV potassium chloride (KCl) to a patient with hypokalemia, monitoring cardiac electrical activity—particularly changes on the electrocardiogram (ECG) or cardiac monitor—is the nurse's highest priority during assessment. Although hypokalemia can also cause muscle cramps, constipation (manifesting as diminished bowel sounds), and pain at the IV insertion site (possibly related to KCl infusion irritation), the urgency and potential danger of these manifestations are much lower than the development of life-threatening arrhythmias. According to the ABC principle (Airway, Breathing, Circulation), cardiac function is directly tied to the stability of circulation, so monitoring cardiac rhythm carries the highest priority.