Osterloh J D
Clinical Laboratory Medicine and Medicine, University of California, San Francisco.
Emerg Med Clin North Am. 1990 Aug;8(3):693-723.
Emergency physicians using toxicologic testing should learn the capabilities of their laboratories: What is detectable? What is not? What is the expected turnaround time? Do pharmacologic relationships exist? In ordering test requests, the laboratory should allow the physician to order limited test combinations, and the physician can assist the laboratory in the search for unknowns by indicating the running diagnosis and suspected drugs. Only a few drugs require quantitation in serum in order to assist in therapeutic decisions. Urine drug screening is useful in documenting intoxications due to drugs and frequently demonstrates more drugs or drugs other than those clinically expected. The impact of findings from emergency drug screening upon diagnosis and therapy appears to be low. Although comprehensive drug screening in the emergency setting has a better positive predictive value ("rule-in") than negative predictive value, toxicologic screening may be useful as a "rule-out" test in other diagnostic applications of lower prior probability. Future directions in laboratory diagnosis of the intoxicated patient are likely to include growth in new immunoassays with limited applications, but with rapid turnaround within the Emergency Department. Also, with improvements in technology, screening of serum drugs will become more common, including the discovery of more quantitative relationships between serum concentration and toxic effects.
能检测出什么？检测不出什么？预期的周转时间是多久？是否存在药物关系？在下达检测申请时，实验室应允许医生订购有限的检测组合，医生可以通过指明初步诊断和疑似药物来协助实验室查找未知物质。只有少数药物需要检测血清中的含量以辅助治疗决策。尿液药物筛查有助于记录药物中毒情况，且常常能检测出比临床预期更多的药物或其他药物。急诊药物筛查结果对诊断和治疗的影响似乎较小。尽管在急诊环境中进行全面药物筛查的阳性预测值（“确诊”）高于阴性预测值，但在其他先验概率较低的诊断应用中，毒理学筛查作为“排除”检测可能会有用。对中毒患者进行实验室诊断的未来方向可能包括应用有限但周转迅速的新型免疫测定法的增加，这些测定法可在急诊科快速得出结果。此外，随着技术的进步，血清药物筛查将变得更加普遍，包括发现血清浓度与毒性作用之间更多的定量关系。
