Kriikku Pirkko, Wilhelm Lars, Jenckel Stefan, Rintatalo Janne, Hurme Jukka, Kramer Jan, Jones A Wayne, Ojanperä Ilkka
Vita Laboratory, Helsinki, Finland; Department of Forensic Medicine, Hjelt Institute, University of Helsinki, Finland.
LADR GmbH Medizinisches Versorgungszentrum, Geesthacht, Germany.
Forensic Sci Int. 2014 Jun;239:57-61. doi: 10.1016/j.forsciint.2014.03.019. Epub 2014 Mar 26.
Hand-held electronic breath-alcohol analyzers are widely used by police authorities in their efforts to detect drunken drivers and to improve road-traffic safety. Over a three month period, the results of roadside breath-alcohol tests of drivers apprehended in Finland were compared with venous blood alcohol concentration (BAC). The mean (median) time between sampling blood and breath was 0.71h (0.58h) with a range from 0 to 6h. Some hand-held instruments gave results as the concentration of alcohol in breath and were converted into BAC assuming a blood-breath alcohol ratio (BBR) of 2260. The mean venous BAC (1.82g/kg) in traffic offenders was higher than the result predicted by the hand-held breath analyzers (1.72g/kg). In 1875 roadside tests, the relationship between venous BAC (x) and BrAC (y) was defined by the regression equation y=0.18+0.85x. The coefficients show both a constant bias (y-intercept 0.18g/kg) and a proportional bias (slope=0.85). The residual standard deviation (SD), an indicator of random variation, was ±0.40g/kg. After BAC results were corrected for the time elapsed between sampling blood and breath, the y-intercept decreased to 0.10g/kg and 0.004g/kg, respectively, when low (0.1g/kg/h) and high (0.25g/kg/h) rates of alcohol elimination were used. The proportional bias of 0.85 shows that the breath-alcohol test result reads lower than the actual BAC by 15% on average. This suggests that the BBR of 2260 used for calibration should be increased by about 15% to give closer agreement between BAC and BrAC. Because of the large random variation (SD±0.40g/kg), there is considerable uncertainty if and when results from the roadside screening test are used to estimate venous BAC. The roadside breath-alcohol screening instruments worked well for the purpose of selecting drivers above the statutory limit of 0.50g/kg.
手持式电子呼气酒精分析仪被警方广泛用于检测酒后驾车者并提高道路交通安全。在三个月的时间里，对芬兰路边截停的司机进行的呼气酒精测试结果与静脉血酒精浓度（BAC）进行了比较。采血和呼气之间的平均（中位数）时间为0.71小时（0.58小时），范围从0到6小时。一些手持式仪器给出的结果是呼气中的酒精浓度，并假设血-呼气酒精比率（BBR）为2260将其转换为BAC。交通违法者的平均静脉BAC（1.82g/kg）高于手持式呼气分析仪预测的结果（1.72g/kg）。在1875次路边测试中，静脉BAC（x）和呼气酒精浓度（BrAC，y）之间的关系由回归方程y = 0.18 + 0.85x定义。这些系数显示出恒定偏差（y轴截距为0.18g/kg）和比例偏差（斜率 = 0.85）。残余标准差（SD）是随机变化的指标，为±0.40g/kg。在对采血和呼气之间经过的时间对BAC结果进行校正后，当采用低（0.1g/kg/h）和高（0.25g/kg/h）酒精消除率时，y轴截距分别降至0.10g/kg和0.004g/kg。0.85的比例偏差表明，呼气酒精测试结果平均比实际BAC低15%。这表明用于校准的2260的BBR应提高约15%，以使BAC和BrAC之间的一致性更高。由于存在较大的随机变化（SD±0.40g/kg），如果使用路边筛查测试结果来估计静脉BAC，以及何时使用，存在相当大的不确定性。路边呼气酒精筛查仪器在筛选法定限度0.50g/kg以上的司机方面效果良好。
