一位病人因糖尿病酮酸中毒（DKA）入院。實驗室檢查顯示血糖為 520 mg/dL，血清鉀為 3.2 mEq/L。護理師應優先執行哪項醫囑？
A client is admitted with a diagnosis of diabetic ketoacidosis (DKA). The laboratory results reveal a blood glucose of 520 mg/dL and a serum potassium of 3.2 mEq/L. Which provider order should the nurse implement first?
- AAdminister 1000 mL of 0.9% Normal Saline over 1 hour於1小時內輸注1000 mL 0.9% 生理食鹽水
- BAdminister 40 mEq of Potassium Chloride IV piggyback✓ 正解靜脈滴注40 mEq 氯化鉀
- CObtain an arterial blood gas (ABG) sample抽取動脈血氣（ABG）樣本
- DStart a continuous intravenous insulin infusion at 0.1 units/kg/hr開始以0.1 units/kg/hr之速率持續靜脈輸注胰島素
這是 NCLEX 中極具挑戰性的『優先順序』題型。雖然 DKA 的核心問題是胰島素缺乏和高血糖，但當血鉀低於 3.3 mEq/L 時，必須優先補鉀。為什麼？因為胰島素會將鉀離子從細胞外液推入細胞內，這會使原本就低的血鉀進一步下降，可能導致致命的心律不整。核心概念是：安全用藥（Safety First）。在補鉀到 3.3 mEq/L 以上之前，給予胰島素（D）是禁忌。雖然生理食鹽水（A）對於擴充容積很重要，但低血鉀的生命威脅比脫水更即時。ABG（C）是診斷工具，不能解決生理急迫性。臨床思路應為：低鉀（K < 3.3）→ 先補鉀 → 等血鉀回升 → 再打胰島素。若血鉀正常或偏高，則首選處置通常是輸液補充（A）。
This is a highly challenging 'priority-setting' question on the NCLEX. Although the core problems in DKA are insulin deficiency and hyperglycemia, when serum potassium is below 3.3 mEq/L, potassium replacement takes priority. Why? Because insulin drives potassium from the extracellular into the intracellular compartment, lowering the already-low serum potassium further and possibly causing fatal arrhythmias. The core concept is safety first: insulin (D) is contraindicated until potassium reaches at least 3.3 mEq/L. Although normal saline (A) is important for volume expansion, the life-threatening risk of hypokalemia is more immediate than that of dehydration. ABG (C) is a diagnostic tool and does not address the physiologic emergency. The clinical pathway is: hypokalemia (K < 3.3) -> replace potassium first -> wait for the level to rise -> then start insulin. If potassium is normal or elevated, fluid replacement (A) is usually the first choice.
在美國 NCLEX 考試中，這題測試的是對處置順序的極致理解，嚴格遵循 ADA 指引（K < 3.3 不可給胰島素）。在台灣臨床，醫師通常會同步開立多項醫囑，護理師可能同時架起點滴與胰島素幫浦，但若發現血鉀過低，優秀的護理師應主動與醫師溝通，調整執行的優先順序，這點在兩地臨床判斷上的要求是一致的。