Fraser Albert D
Toxicology Laboratory, Pathology & Laboratory Medicine, Queen Elizabeth II Health Sciences Center, Dalhousie University, Halifax, Nova Scotia, Canada B3H 2Y9.
Ther Drug Monit. 2002 Apr;24(2):232-8. doi: 10.1097/00007691-200204000-00005.
Metabolic pathways have been elucidated for various chemical and solvent exposures in humans. Clinical laboratory analyses in most chemical and solvent exposures are directed toward identification and quantitation of unchanged substance in serum or whole blood. For example, most laboratories routinely screen for unchanged ethylene glycol in suspected poisonings and quantitate ethylene glycol in positive cases even though toxicity from ethylene glycol exposure (including central nervous system depression, acute renal failure, and elevated anion gap metabolic acidosis) is primarily caused by one metabolite-glycolic acid. One objective of this manuscript is to describe the authors' clinical experience with glycolic acid analysis in ethylene glycol human poisonings. Recommended clinical laboratory tests for small hospitals and toxicology reference laboratories are presented to rule out or confirm ethylene glycol exposure. Another concern with laboratory support in ethylene glycol poisoning is correct identification of ethylene glycol because analysis of this substance is often problematic. In one case laboratories incorrectly identified an organic acid from an inherited metabolic disease as ethylene glycol, and in another case the intentional ethylene glycol poisoning of an infant was determined to be the results of an endogenous organic acid. The most robust analytical methods for determining ethylene glycol and glycolic acid are chromatographic methods. Ideally, screening methods for ethylene glycol should be confirmed by another method based on a different principle of analysis or include simultaneous metabolite analysis (glycolic acid). In centers where several ethylene glycol cases present annually, toxicology laboratories supporting these centers should incorporate glycolic acid monitoring in their ethylene glycol screening programs and include analysis of both ethylene glycol and glycolic acid during treatment (hemodialysis) in all confirmed poisonings. Measurement of glycolic acid provides important diagnostic and prognostic information that one cannot correlate with the amount of ethylene glycol in serum or whole blood.
人类接触各种化学物质和溶剂后的代谢途径已得到阐明。在大多数化学物质和溶剂接触的临床实验室分析中，主要是针对血清或全血中未发生变化的物质进行鉴定和定量。例如，大多数实验室在疑似中毒病例中常规筛查未发生变化的乙二醇，并对阳性病例中的乙二醇进行定量，尽管乙二醇接触导致的毒性（包括中枢神经系统抑制、急性肾衰竭和阴离子间隙代谢性酸中毒升高）主要是由一种代谢产物——乙醇酸引起的。本手稿的一个目的是描述作者在乙二醇中毒患者乙醇酸分析方面的临床经验。文中介绍了小型医院和毒理学参考实验室推荐的临床实验室检测方法，以排除或确认乙二醇接触。乙二醇中毒实验室支持方面的另一个问题是正确鉴定乙二醇，因为该物质的分析往往存在问题。在一个案例中，实验室将一种遗传性代谢疾病中的有机酸错误鉴定为乙二醇，而在另一个案例中，一名婴儿的故意乙二醇中毒被认定是内源性有机酸所致。测定乙二醇和乙醇酸最可靠的分析方法是色谱法。理想情况下，乙二醇的筛查方法应通过基于不同分析原理的另一种方法进行确认，或者包括同时进行代谢产物分析（乙醇酸）。在每年出现多例乙二醇中毒病例的中心，为这些中心提供支持的毒理学实验室应在其乙二醇筛查项目中纳入乙醇酸监测，并在所有确诊中毒病例的治疗（血液透析）过程中同时分析乙二醇和乙醇酸。测定乙醇酸可提供重要的诊断和预后信息，而这些信息无法与血清或全血中的乙二醇含量相关联。
