Department of Emergency Medicine, Naval Medical Center, San Diego, CA 92134-5000, USA.
Clin Toxicol (Phila). 2013 Jun;51(5):398-401. doi: 10.3109/15563650.2013.791695. Epub 2013 May 3.
The contribution of ethanol ([EtOH]) to the osmol gap (OG) is commonly described by the formula [EtOH (mg/dL)]/k, where k is assumed to be 4.6 (one-tenth of its molecular weight) if ethanol behaves ideally in solution. However, several studies on convenience samples of patients suggest that ethanol does not behave ideally and that k may be significantly different from this ideal constant.
To determine prospectively the relationship between serum ethanol concentration and total serum osmolality in a group of healthy volunteers.
Experimental subjects ingested 20 mL of 100% ethanol diluted in sugar-free soda at a rate of one drink every 10 min, up to a maximum of seven drinks. Control subjects ingested 20 mL of water diluted in sugar-free soda at the same rate. Blood samples were obtained at baseline and then at every 20 min for 180 min to measure serum [EtOH] concentration, electrolytes, glucose, and osmolality (via freezing-point depression). The OG was calculated by subtracting predicted osmolality from measured osmolality. The OG was then divided by [EtOH] to determine the coefficient of ethanol's contribution to total serum osmolality.
A total of 10 volunteers (five men and five women; mean age, 38.8 years, and range, 28-49 years) participated in and completed the study. Eight (four male and four female) were in the experimental group, and two (one male and one female) were in the control group. Mean peak [EtOH] was 229 mg/dL (median, 223.5 mg/dL; IQR, 171-273 mg/dL) and a linear relationship between [EtOH] and OG (Pearson coefficient of 0.98) was found. Using covariate correction for each subject's baseline OG, k was calculated to be 4.25 (95% CI, 4.13-4.38) averaged over all participants.
In this volunteer study, the coefficient describing the contribution of ethanol to serum osmolality (k) was found to be 4.25. This indicates that ethanol contributes more to total serum osmolality than would be predicted for an ideal solute.
乙醇（[EtOH]）对渗透间隙（OG）的贡献通常通过公式[EtOH（mg/dL）]/k 来描述，其中 k 假定为 4.6（其分子量的十分之一），如果乙醇在溶液中表现理想。然而，对患者便利样本的几项研究表明，乙醇的行为并不理想，k 可能与这个理想常数有很大的不同。
在一组健康志愿者中，前瞻性地确定血清乙醇浓度与总血清渗透压之间的关系。
实验对象以每 10 分钟一杯的速度摄入 20 毫升 100%乙醇稀释在无糖苏打水中，最多可摄入七杯。对照对象以相同的速度摄入 20 毫升无糖苏打水稀释的水。在基线和 180 分钟内每 20 分钟采集一次血样，以测量血清[EtOH]浓度、电解质、葡萄糖和渗透压（通过冰点降低法）。OG 通过从测量的渗透压中减去预测的渗透压来计算。OG 然后除以[EtOH]，以确定乙醇对总血清渗透压的贡献系数。
共有 10 名志愿者（5 名男性和 5 名女性；平均年龄 38.8 岁，范围 28-49 岁）参与并完成了这项研究。8 人（4 名男性和 4 名女性）在实验组，2 人（1 名男性和 1 名女性）在对照组。平均峰值[EtOH]为 229mg/dL（中位数 223.5mg/dL；IQR 171-273mg/dL），发现[EtOH]与 OG 之间存在线性关系（Pearson 系数为 0.98）。对每个受试者的基线 OG 进行协变量校正后，计算出 k 在所有参与者中的平均值为 4.25（95%CI，4.13-4.38）。
在这项志愿者研究中，描述乙醇对血清渗透压贡献的系数（k）为 4.25。这表明，与理想溶质相比，乙醇对总血清渗透压的贡献更大。
