渗透压间隙与计算得出的酒精浓度之间的差异。

Discrepancies in osmolal gaps and calculated alcohol concentrations.

作者信息

Osterloh J D, Kelly T J, Khayam-Bashi H, Romeo R

机构信息

Department of Clinical Laboratory Medicine, University of California, San Francisco, USA.

出版信息

Arch Pathol Lab Med. 1996 Jul;120(7):637-41.

PMID:8757467

Abstract

OBJECTIVES

To estimate unexplained osmolal gaps (UEOG) during ethanol ingestions after accounting for measured ethanol concentrations and to explore the causes of observed discrepancies. DESIGN AND SPECIMENS: A random convenience sample of serum specimens with a request to perform osmometry for the detection of alcohols was studied.

MAIN OUTCOME MEASURES

Serum concentrations of sodium, glucose, urea nitrogen, ethanol, osmolality, and ethanol were measured by two analytic methods to determine calculated osmolalities and osmolal gaps using two commonly used formulas.

RESULTS

In 79 serum specimens submitted for osmometry, mean ethanol concentrations were 199 +/- 154 (SD) mg/dL; 15 specimens had no detectable ethanol. After regression of the calculated ethanol concentrations and the measured ethanol concentrations, the Dorwart and Chalmers formula showed a large constant bias of 45.217 +/- 6.414 (SE) mOsm/kg in predicting measured ethanol concentrations. The Smithline and Gardner formula was similarly as precise (r = .9786), but had a much smaller bias of -3.929 +/- 6.623 (SE) mOsm/kg. Actual mean differences between measured and calculated osmolalities (including ethanol osmols) gave an estimate of UEOG seen during ethanol ingestions. Using the less biased formula, the mean UEOG was 1.4 +/- 8.5 mOsm/kg, giving a 95% upper limit of the reference range of 18 mOsm/kg in this population with ethanol ingestions. Three significant outliers were identified and their UEOG could be explained by the presence of mannitol, isopropanol, or possibly a change in the assumed value for fractional water, normally a constant in these formulas for calculated osmolality. Other specific causes of osmolal gap and UEOG are discussed.

CONCLUSION

The potential range of osmolal gaps seen during ethanol ingestions after accounting for ethanol is demonstrated to be greater than in previous studies, which have included a lower proportion of ethanol-intoxicated subjects in their study sample.

摘要

目的

在考虑测量的乙醇浓度后估计乙醇摄入期间的 unexplained osmolal gaps（UEOG），并探讨观察到差异的原因。设计与样本：研究了一个随机便利样本的血清标本，这些标本被要求进行渗透压测定以检测酒精。

主要观察指标

通过两种分析方法测量血清中钠、葡萄糖、尿素氮、乙醇、渗透压和乙醇的浓度，以使用两个常用公式确定计算的渗透压和渗透压间隙。

结果

在提交进行渗透压测定的79份血清标本中，平均乙醇浓度为199±154（标准差）mg/dL；15份标本未检测到乙醇。在计算的乙醇浓度与测量的乙醇浓度进行回归后，Dorwart和Chalmers公式在预测测量的乙醇浓度时显示出45.217±6.414（标准误）mOsm/kg的大常数偏差。Smithline和Gardner公式同样精确（r = 0.9786），但偏差小得多，为-3.929±6.623（标准误）mOsm/kg。测量和计算的渗透压（包括乙醇渗透压）之间的实际平均差异给出了乙醇摄入期间观察到的UEOG的估计值。使用偏差较小的公式，平均UEOG为1.4±8.5 mOsm/kg，在该乙醇摄入人群中给出了参考范围的95%上限为18 mOsm/kg。识别出三个显著异常值，它们的UEOG可以通过甘露醇、异丙醇的存在或可能是分数水的假定值变化来解释，分数水在这些计算渗透压的公式中通常是一个常数。还讨论了渗透压间隙和UEOG的其他具体原因。