Department of Emergency Medicine, University of Texas Health Science Center, San Antonio, Texas.
Department of Emergency Medicine, University of Texas Health Science Center, San Antonio, Texas; South Texas Poison Center, University of Texas Health Science Center, San Antonio, Texas.
J Emerg Med. 2024 Mar;66(3):e341-e345. doi: 10.1016/j.jemermed.2023.07.001. Epub 2023 Aug 18.
The estimated serum osmolality is a measurement of solutes in the blood, including sodium, glucose, and urea, but also includes ethanol and toxic alcohols (e.g., methanol, ethylene glycol, diethylene glycol, isopropyl alcohol, propylene glycol) when present. These rarely measured toxic alcohols can elevate the serum osmolality, giving the true measured osmolality. The difference between that and a calculated osmolality is the osmolal gap, which can be elevated in many clinical scenarios such as renal failure, ingestion of toxic alcohols, diabetic ketoacidosis, shock, and others.
We report a patient with a history of alcohol use disorder who came to the Emergency Department with an abnormally elevated osmolal gap in the setting of altered mental status. The patient's increased osmolal gap was further investigated while he was promptly treated with fomepizole, thiamine, and urgent hemodialysis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: We discuss the differential diagnosis for substances that increase the osmolal gap with respective ranges of elevation. This case demonstrates that although osmolal gap elevation is often attributed to the presence of toxic alcohols, other common etiologies may account for the gap, including acute renal failure and multiple myeloma.
估计的血清渗透压是对血液中溶质的测量，包括钠、葡萄糖和尿素，但当存在乙醇和有毒醇（如甲醇、乙二醇、二乙二醇、异丙醇、丙二醇）时也包括这些很少测量的有毒醇。这些有毒醇会升高血清渗透压，给出真实的测量渗透压。实际测量渗透压与计算渗透压之间的差值即为渗透压间隙，在肾衰竭、摄入有毒醇、糖尿病酮症酸中毒、休克等多种临床情况下，渗透压间隙可能会升高。
我们报告了一位有酒精使用障碍病史的患者，他因精神状态改变而来到急诊室，出现异常升高的渗透压间隙。在对患者进行治疗的同时，我们对其升高的渗透压间隙进行了进一步调查，治疗包括使用福米韦地尔、硫胺素和紧急血液透析。
为什么急诊医生应该了解这个问题？：我们讨论了导致渗透压间隙升高的物质的鉴别诊断及其相应的升高范围。这个病例表明，尽管渗透压间隙升高通常归因于有毒醇的存在，但其他常见病因也可能导致间隙升高，包括急性肾衰竭和多发性骨髓瘤。
