護理師照顧一名有肝硬化病史的病患，其表現出意識混亂增加及撲翼樣震顫（asterixis）。護理師應最密切監測哪項實驗室數值？
A nurse is caring for a client with a history of cirrhosis who is presenting with increased confusion and asterixis. Which laboratory value should the nurse monitor most closely?
- AProthrombin time (PT)凝血酶原時間 (PT)
- BSerum bilirubin血清膽紅素
- CAlanine aminotransferase (ALT)丙氨酸胺基轉殖酶 (ALT)
- DSerum ammonia✓ 正解血清氨
病患出現意識混亂（Confusion）與撲翼樣震顫（Asterixis，手部無法維持姿勢而產生的拍擊樣動作）是肝性腦病變（Hepatic Encephalopathy）的典型徵兆。這主要是因為肝功能衰竭無法將蛋白質代謝產生的「氨」（Ammonia）轉化為尿素，導致血氨升高並穿過血腦屏障產生神經毒性。因此，監測血氨數值（D）對於評估病情嚴重程度與治療效果（如 Lactulose 的使用）至關重要。雖然膽紅素（B）與凝血時間（A）在肝病中也很重要，但與目前的神經系統症狀直接相關的是血氨。
The client's presentation of confusion and asterixis (a flapping tremor due to the inability to maintain a posture of the hands) is a classic sign of hepatic encephalopathy. This occurs because liver failure impairs the conversion of ammonia, a byproduct of protein metabolism, into urea, leading to elevated serum ammonia that crosses the blood-brain barrier and produces neurotoxicity. Monitoring serum ammonia (D) is therefore essential for assessing the severity of the condition and the response to treatment (such as lactulose). Although bilirubin (B) and prothrombin time (A) are also important in liver disease, the laboratory value most directly related to the current neurologic symptoms is serum ammonia.
美國護理實務中，對於肝性腦病變的評估常結合 Glasgow Coma Scale (GCS) 與血氨值；台灣臨床同樣重視血氨，並會嚴格觀察病患排便次數，以確保 Lactulose 達到每日 2-3 次軟便的降氨目標。