每日一题_2022.3.12

A 54-year-old man presents with septic shock due to left lower extremity cellulitis with methicillin- resistant Staphylococcus aureus bacteremia. He develops respiratory failure that requires intubation, and is placed on mechanical ventilation. The ICU team starts a fentanyl infusion at 250 μg/hour and a lorazepam infusion at 10 mg/hour for analgosedation. Four days later, he develops metabolic acidosis, new-onset renal failure, and an osmolar gap.

Which of the following substances is the most likely explanation for the new metabolic derangements

A. Ethylene glycol

B. Isopropylalcohol 

C. Cyanide

D. Methanol

E. Propylene glycol

答案解析：

由于其不溶性，注射用劳拉西泮在丙二醇中稀释。劳拉西泮输注超过48小时，特别是6 ~ 8 mg/h或更大剂量时，可发生丙二醇毒性；出现渗透压间隙、代谢性酸中毒、不明原因的新发肾衰竭和呼吸衰竭，应及时关注丙二醇毒性，并应停用劳拉西泮。

正确答案：E

补充内容：

Propylene glycol is the carrier of intravenous lorazepam and has been implicated in anion-gap metabolic acidosis in patients in the intensive care unit. However, anion-gap metabolic acido- sis typically occurs when high doses of intrave- nous lorazepam are administered for 24 hours or longer. Because of the 10-hour time frame in this case, toxicity due to propylene glycol from intravenous lorazepam is unlikely.

丙二醇是静脉注射劳拉西泮的载体，与重症监护室患者的阴离子间隙代谢性酸中毒有关。然而，当静脉给予高剂量劳拉西泮24小时或更长时间时，通常会发生阴离子间隙代谢性酸中毒。由于该病例的时间范围为10小时，因此不太可能因静脉注射劳拉西泮产生丙二醇毒性。