護理師準備為一位深部靜脈栓塞 (DVT) 病人靜脈注射肝素 (Heparin)。護理師應監測哪項檢驗結果來調整肝素的滴注速率？
A nurse is preparing to administer intravenous heparin to a client with deep vein thrombosis (DVT). Which laboratory result should the nurse monitor to adjust the heparin infusion rate?
- APlatelet count血小板計數
- BActivated partial thromboplastin time (aPTT)✓ 正解活化部分凝血活酶時間 (aPTT)
- CInternational Normalized Ratio (INR)國際標準化比值 (INR)
- DProthrombin time (PT)凝血酶原時間 (PT)
靜脈滴注肝素（Unfractionated Heparin, UFH）的主要監測指標是活化部分凝血活酶時間（aPTT）。肝素透過加速抗凝血酶 III 的作用來抑制凝血酶，其治療目標通常是維持在正常值的 1.5 到 2.5 倍之間。若 aPTT 過低，血栓風險增加；若過高，則出血風險上升，護理師需根據醫院的標準草案（Protocol）調整流速。選項 D 和 C（PT/INR）是用於監測口服抗凝血藥 Warfarin 的指標，而非肝素。選項 A（血小板計數）雖然在肝素治療中也需要監測，是為了篩檢『肝素誘發之血小板低下症』（HIT），但它並非用來「調整滴注速率」的依據。臨床安全重點在於：給藥前必須雙人核對，並在調整速率後 4-6 小時重新採檢 aPTT，直到數值穩定。這題測驗護理師對不同抗凝血藥監測指標的精確區分，這是 NCLEX 常考的高頻考點。
The primary monitoring parameter for intravenous unfractionated heparin (UFH) is the activated partial thromboplastin time (aPTT). Heparin works by accelerating the action of antithrombin III to inhibit thrombin, and its therapeutic target is generally 1.5 to 2.5 times the normal value. If aPTT is too low, the risk of thrombosis increases; if too high, the risk of bleeding rises. The nurse adjusts the infusion rate according to the institutional protocol. Options D and C (PT/INR) are used to monitor the oral anticoagulant warfarin, not heparin. Although option A (platelet count) must also be monitored during heparin therapy to screen for heparin-induced thrombocytopenia (HIT), it is not the basis for 'adjusting the infusion rate.' From a safety standpoint, the medication must be double-checked by two persons prior to administration, and aPTT should be re-drawn 4–6 hours after a rate adjustment until the value stabilizes. This question tests precise differentiation among anticoagulant monitoring parameters — a high-frequency NCLEX topic.
在美國，許多醫院採行護理師主導的肝素調整草案（Nurse-led Heparin Protocol），護理師根據 aPTT 或 Anti-Xa 數值，無需再次詢問醫師即可直接調整流速。台灣臨床雖然也有草案，但實務上護理師在調整流速後，通常仍需在醫囑系統上進行確認，或由醫師根據檢驗值重新開立流速醫囑，自主權限範圍略有不同。