每日一题_2022.3.26

A 24-year-old woman with a history of depression is brought to the emergency department by emergency medical services (EMS) for lethargy and confusion. The patient was last seen by family about eight hours ago. Emergency medical service personnel had found an empty bottle of acetaminophen at the scene. The patient has a Glasgow Coma Scale score of 10, but is hypotensive. She requires a 2-liter bolus of IV fluid to stabilize her blood pressure. Laboratory findings are: aspartate aminotransferase 54 U/L, alanine aminotransferase 32 U/L, alkaline phosphate 110 U/L, albumin 3.8 g/dL, INR 1.2, lactate 1.0 mg/dL. Arterial blood gas analysis reveals: pH 7.35, partial pressure of carbon dioxide 35 mm Hg, partial pressure of oxygen 95 mm Hg. Acetaminophen level is 400 mg/dL. ECG shows normal sinus rhythm.

Which of the following is the most appropriate next step in this patient’s management?

A. Naloxone

B. Vasopressors

C. Intubation

D. Observation

E. N-acetylcysteine

答案解析：

对乙酰氨基酚毒性是急诊科最常见的药物毒性之一，因为其广泛的非处方可用性。对乙酰氨基酚毒性有四个临床阶段：第1阶段（0-24小时）：无症状，转氨酶轻度升高；第2阶段（18-72小时）：右上腹疼痛、低血压；第3阶段（72-96小时）：黄疸、低血糖、凝血障碍；第4阶段（4天-3周）：恢复。该患者处于第1阶段，由于她对IV液体仍有反应，因此无插管或血管加压药的适应症。

纳洛酮对对乙酰氨基酚过量没有作用，因为服用对乙酰氨基酚的患者会消耗其谷胱甘肽储备，导致N-乙酰-对苯并醌亚胺(NAPQI)过量。过量的NAPQI在肝细胞中进一步繁殖，导致肝坏死。N-乙酰半胱氨酸(NAC)补充了肝脏中耗尽的谷胱甘肽储备，并增强了对乙酰氨基酚的无毒代谢。对乙酰氨基酚过量的患者根据Rumack-Matthew列线图进行分层；所有高危患者均应开始NAC治疗，最好在天冬氨酸转氨酶(AST)升高之前，并持续至AST未升高或血清对乙酰氨基酚水平检测不到。如果患者出现肝功能障碍体征或接受大剂量对乙酰氨基酚(> 30 g)或血清对乙酰氨基酚水平高于500 mg/L，则应将患者转移至肝移植中心，以紧急评估可能的即将发生的肝衰竭。

正确答案：E

补充内容：

Acetaminophen Overdose and NAC Dosing：https://www.mdcalc.com/acetaminophen-overdose-nac-dosing