病人的血鉀濃度為 2.8 mEq/L。護理師應優先進行哪項評估？
A client has a potassium level of 2.8 mEq/L. Which of the following is the most important assessment for the nurse to prioritize?
- AMuscle strength in the extremities評估四肢肌肉力量
- BDeep tendon reflexes評估深部肌腱反射
- CBowel sounds評估腸鳴音
- DElectrocardiogram (ECG) rhythm✓ 正解評估心電圖 (ECG) 節律
血鉀濃度為 2.8 mEq/L 屬於低血鉀症（hypokalemia），正常血鉀範圍為 3.5-5.0 mEq/L。低血鉀會對全身多個系統產生影響，其中對心臟的影響最為嚴重且具生命威脅性。鉀離子在維持心肌細胞的電生理穩定性中扮演關鍵角色，其濃度過低會導致心肌細胞膜電位異常，增加心律不整（cardiac arrhythmias）的風險。 因此，在面對顯著的低血鉀時，護理師應優先監測心電圖（Electrocardiogram, ECG）節律，以偵測任何可能出現的心臟電生理變化，例如 T 波變平或倒置、U 波出現、ST 段壓低、PR 間期延長，甚至可能導致室性心動過速或心室顫動等致命性心律不整。這是基於 ABC（Airway, Breathing, Circulation）原則中循環系統的優先考量。
A potassium level of 2.8 mEq/L indicates significant hypokalemia, which poses an immediate threat to cardiac stability due to the risk of life-threatening dysrhythmias. Potassium is critical for maintaining the electrical activity of the heart, and low levels can cause changes such as flattened T waves, U waves, and ST-segment depression. Therefore, monitoring the electrocardiogram (ECG) rhythm is the highest priority assessment.