護理師準備為病人靜脈輸注 20 mEq 的氯化鉀。下列哪項護理措施是執行前必須做的？

靜脈輸注氯化鉀（Potassium Chloride, KCl）是補充體內鉀離子不足的常用方法，但鉀離子具有潛在的毒性，若給予不當，可能引發嚴重的心律不整甚至心跳停止。因此，給予 KCl 前必須嚴格評估病人的狀況，確保安全。 核心安全考量是鉀離子的排泄。鉀離子主要經由腎臟代謝和排泄，若病人的腎功能不佳，尿量不足，輸注 KCl 就會導致鉀離子在體內堆積，引發高血鉀（Hyperkalemia）。高血鉀會嚴重影響心臟傳導系統，是輸注 KCl 前最重要的安全評估點。 選項 C（確認尿量至少 30 mL/hr）是評估腎臟排泄功能的關鍵指標。成人腎臟每小時應能排出至少 30-50 mL 的尿液，代表腎臟有足夠的過濾和排泄能力。若尿量不足，則應暫緩輸注 KCl。 選項 A（檢查周邊靜脈路徑通暢）固然重要，但相較於評估腎功能，對 KCl 輸注的直接安全性影響較小。選項 D（稀釋於 500 mL 生理食鹽水）是正確操作的一部分，但稀釋量需依醫囑與病人狀況而定，且不是最優先的執行前步驟。選項 B（IV bolus push）是絕對禁止的，如前述，會引發致命性後果。

Intravenous potassium chloride (KCl) is a common method for replacing depleted potassium, but potassium has potential toxicity; improper administration can cause severe arrhythmias and even cardiac arrest. Therefore, the client's status must be carefully assessed before administration. The core safety concern is potassium excretion. Because potassium is metabolized and excreted mainly by the kidneys, impaired renal function with low urine output can cause potassium to accumulate during infusion, producing hyperkalemia. Hyperkalemia severely affects cardiac conduction and is the most important safety consideration before infusing KCl. Option C (confirming urine output of at least 30 mL/hr) is a key indicator of renal excretory function. An adult's kidneys should produce at least 30-50 mL of urine per hour, indicating adequate filtration and excretory capacity. If urine output is inadequate, the KCl infusion should be withheld. Option A (checking the patency of the peripheral IV site) is also important, but its direct impact on the safety of a KCl infusion is smaller than that of the renal-function assessment. Option D (diluting in 500 mL of normal saline) is part of correct administration, but the dilution volume depends on the prescription and the client's status and is not the highest-priority preadministration step. Option B (IV bolus push) is strictly forbidden, as discussed above, because it can be fatal.