Sewell Chaundra R, Rivey Michael P
1 Community Medical Center, Missoula, MT, USA.
2 University of Montana Skaggs School of Pharmacy, Missoula, MT, USA.
J Pharm Pract. 2018 Oct;31(5):507-509. doi: 10.1177/0897190017723211. Epub 2017 Aug 14.
Methemoglobinemia is a serious medical condition characterized by the disrupted binding of oxygen to iron on hemoglobin, with a consequent impaired oxygen delivery to body tissues. Various drugs including the local anesthetics such as benzocaine can cause acquired methemoglobinemia. The reported case describes methemoglobinemia that occurred in association with the use of topical benzocaine spray and lozenges in a previously healthy 51-year-old female who had undergone colon surgery to remove a bleeding polyp. Pulse oximetry revealed the patient was hypoxic and a measured methemoglobin (MetHB) serum concentration was 32.4%, well above the normal of less than 2%. Treatment with intravenous methylene blue resulted in a rapid improvement in the patient's respiratory status. The case emphasizes the need for practitioners to appreciate that topical benzocaine products can cause potentially fatal methemoglobinemia.
高铁血红蛋白血症是一种严重的医学病症，其特征是氧气与血红蛋白上的铁结合受到破坏，从而导致向身体组织输送氧气受损。包括局部麻醉剂如苯佐卡因在内的各种药物可引起获得性高铁血红蛋白血症。所报告的病例描述了一名51岁的既往健康女性，在接受结肠手术切除出血性息肉后，使用外用苯佐卡因喷雾剂和含片引发了高铁血红蛋白血症。脉搏血氧饱和度测定显示患者缺氧，测得的高铁血红蛋白（MetHB）血清浓度为32.4%，远高于正常水平的2%以下。静脉注射亚甲蓝治疗后，患者的呼吸状况迅速改善。该病例强调了从业者需要认识到外用苯佐卡因产品可能会导致潜在致命的高铁血红蛋白血症。
