Ryu Seung, Oh Se-Kwang, Son Seung-Ha, Jeong Won-Joon, You Yeon-Ho, Ham Young-Rok
Department of Emergency Medicine, Chungnam National University Hospital, Daejeon, Republic of Korea.
Department of Nephrology, Chungnam National University Hospital, Daejeon, Republic of Korea.
J Emerg Med. 2019 Nov;57(5):e153-e156. doi: 10.1016/j.jemermed.2019.06.047. Epub 2019 Oct 4.
Metformin is commonly used for the treatment of type 2 diabetes mellitus. Renal insufficiency is one of the contraindications for its use. Inadvertent prescription in patients with renal insufficiency may lead to metformin-associated lactic acidosis (MALA), which is associated with a high risk of mortality. Consequently, the early recognition and management of MALA is essential.
We present the case of a 68-year-old man who had reversible blindness resulting from severe lactic acidosis. On presentation, he was alert, oriented, and had no complaints except mild abdominal discomfort and blindness. He denied any history of trauma or drug abuse. The results of the laboratory studies showed severe metabolic acidosis with a high anion gap and increased levels of serum creatinine. There were no predisposing ocular or neurologic lesions that could have induced the blindness. Although the blood levels of methanol, ethanol, and metformin were not estimated, correction of acidosis and hemodialysis led to a complete recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Rarely, transient blindness may occur in patients with fatal severe metabolic acidosis. Evaluation for the presence of metabolic acidosis and a detailed medical history are essential in the management of acute blindness in such patients.
二甲双胍常用于治疗2型糖尿病。肾功能不全是其使用的禁忌证之一。肾功能不全患者意外使用二甲双胍可能导致二甲双胍相关性乳酸酸中毒（MALA），这与高死亡率相关。因此，早期识别和处理MALA至关重要。
我们报告一例68岁男性因严重乳酸酸中毒导致可逆性失明的病例。就诊时，他意识清醒、定向力正常，除轻度腹部不适和失明外无其他主诉。他否认有任何外伤或药物滥用史。实验室检查结果显示严重代谢性酸中毒伴高阴离子间隙以及血清肌酐水平升高。不存在可导致失明的眼部或神经系统易患病变。尽管未检测血液中的甲醇、乙醇和二甲双胍水平，但酸中毒的纠正及血液透析使患者完全康复。急诊医生为何应知晓此事？：极少情况下，致命性严重代谢性酸中毒患者可能会出现短暂性失明。对此类患者急性失明进行处理时，评估是否存在代谢性酸中毒及详细询问病史至关重要。
