THE AMERICAN JOURNAL OF CLINICAL PATHOLOGY
Vol. 52, No. 5
Copyright
© 1969 by The Williams & Wilkins Co. Printed
in U.S.A.
SIDNEY KAYE, PH.D., AND EDUARDO CARDONA, M.S.
Department of Pharmacology and Toxicology, School of Medicine and the
Institute of Lega Medicine,
University of Puerto Rico, Río Piedras, Puerto Rico
Kaye, Sidney, and Cardona,
Eduardo: Errors of converting a urine
alcohol value into a blood alcohol level.
Am. J. Clin. Path., 52: 577-584, 1969.
A blood alcohol determination is one of the more frequently requested
analyses in a toxicology or forensic chemical laboratory. There are many reliable methods for
determining the concentration of alcohol in the blood. It is the purpose of this communication to
show that it is, however, not reliable
to determine the concentration of alcohol in the urine and report as a blood
alcohol level. This is not reliable even using the best of
average factors of equivalence. These
factors used are an average of many determinations, some of which show very
wide ranges from the mean. Random
specimens of urine and blood were collected from 148 cases examined for alcohol
content. An average urine-blood alcohol
ratio of 1.28: 1, with a range of 0.21 to 2.66, was obtained. The blood alcohol level was calculated in
each case from the corresponding urine alcohol determination by means of the
average ratio obtained from our data.
In 32 (21.5%) of the cases, the blood figures calculated from the urine
value exceeded the actual level determined in blood. In 51 cases (34.5%) the calculated blood alcohol concentration
was below the determined value. In 65
cases (44%) the values corresponded.
This procedure was repeated using the conversion factor (1.25: 1)
employed in some communities. In this
instance, the calculated blood alcohol concentration exceeded the actual value
in 39 cases (26.5%). In 49 cases (33%)
the calculated value was below the observed level, and in 60 cases (40.5%) the
values corresponded. In view of the
wide ranges in the individual urine-blood alcohol ratios found in most
published reports, we find it hard to understand how so many investigators can
conclude that it is satisfactory procedure to calculate the alcoholic content
of blood, to the second decimal place, from a selected specimen of urine. Our data clearly confirm what other
investigators2, 7 – 10 have claimed: that the relationship
(ratio-range) between the concentrations of alcohol in urine and in blood may
vary widely. This renders it unreliable
to use an average conversion factor in medicolegal cases.
It is accepted that there is a relationship between the degree of alcoholic intoxication and the alcoholic content of any tissue, and that such relationship involves a depression of the central nervous system.
Since the alcoholic content
of the brain of a living individual cannot be determined directly, other body
fluids and excretions are analyzed on the assumption that their alcoholic
content reflects that of the brain.
However, the nature and condition of the sample used are very important
because the alcoholic contents of the various body fluids and tissues are not
comparable under all conditions.
It has been established that the blood alcohol concentration relationship varies with urine, spinal fluid, brain, liver, or serum, and cannot be used interchangeably.
________
Received april 1, 1969;
accepted for publication May 15, 1969.
This study was supported in part by Public Health Service Research Grant
UI AC00184-02 from the National Center for Urban and Industrial Health and by
Grant AC-00184-01; 02 from the U.S. Public Health Service. Material in this report partially fulfilled
the requirements for Mr. Cardona’s Master of Science degree.
|
Case No. |
Urine |
Blood |
Urine-BloodRatio |
Case No. |
Urine |
Blood |
Urine-Blood Ratio |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 |
% 0.10 0.17 0.20 0.16 0.23 0.30 0.08 0.36 0.33 0.19 0.10 0.14 0.08 0.23 0.13 0.21 0.26 0.21 0.10 0.10 0.09 0.42 0.07 0.14 0.16 0.47 0.29 0.20 0.18 0.26 0.32 0.31 0.30 0.14 0.13 0.13 0.35 0.13 0.17 0.35 0.25 0.19 0.15 0.28 0.34 0.09 0.19 0.19 0.25 0.10 0.40 |
% 0.05 0.12 0.23 0.12 0.23 0.23 0.18 0.20 0.19 0.18 0.06 0.13 0.04 0.31 0.19 0.21 0.24 0.17 0.08 0.04 0.09 0.22 0.03 0.11 0.09 0.39 0.24 0.15 0.13 0.28 0.30 0.25 0.29 0.08 0.10 0.09 0.29 0.06 0.10 0.25 0.16 0.16 0.09 0.19 0.40 0.15 0.18 0.14 0.24 0.12 0.27 |
2.00 1.42 0.87 1.33 0.96 1.30 0.22 1.80 1.74 1.05 1.66 1.08 2.00 0.74 0.68 1.00 1.08 1.23 1.25 2.50 1.00 1.91 2.33 1.27 1.77 1.20 1.21 1.33 1.38 0.93 1.07 1.24 1.03 1.75 1.30 1.44 1.21 2.16 1.70 1.40 1.56 1.19 1.66 1.47 0.85 0.60 1.05 1.36 1.04 0.83 1.48 |
52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 |
% 0.05 0.39 0.24 0.14 0.17 0.12 0.30 0.25 0.07 0.26 0.18 0.27 0.13 0.33 0.22 0.38 0.22 0.16 0.12 0.20 0.14 0.37 0.30 0.27 0.10 0.04 0.03 0.32 0.20 0.16 0.03 0.34 0.15 0.16 0.33 0.31 0.49 0.22 0.38 0.22 0.12 0.25 0.22 0.10 0.05 0.24 0.37 0.18 0.23 0.10 0.30 |
% 0.03 0.31 0.22 0.08 0.12 0.08 0.18 0.16 0.04 0.19 0.19 0.18 0.11 0.36 0.15 0.23 0.18 0.10 0.08 0.16 0.10 0.32 0.20 0.17 0.10 0.06 0.02 0.30 0.18 0.10 0.14 0.41 0.09 0.06 0.22 0.25 0.45 0.17 0.24 0.24 0.08 0.24 0.23 0.10 0.03 0.22 0.37 0.13 0.17 0.04 0.29 |
1.66 1.26 1.09 1.75 1.42 1.50 1.66 1.56 1.75 1.37 0.95 1.50 1.18 0.92 1.47 1.65 1.22 1.60 1.50 1.25 1.40 1.15 1.50 1.59 1.00 0.66 1.50 1.06 1.11 1.60 0.21 0.83 1.66 2.66 1.50 1.24 1.09 1.29 1.58 0.91 1.50 1.04 0.95 1.00 1.66 1.09 1.00 1.38 1.35 2.50 1.03 |
Table I - Continued
|
Case No. |
Urine |
Blood |
Urine-Blood Ratio |
Case No. |
Urine |
Blood |
Urine-Blood Ratio |
|
103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 |
% 0.05 0.26 0.07 0.32 0.09 0.29 0.35 0.38 0.14 0.22 0.41 0.19 0.28 0.18 0.18 0.04 0.12 0.23 0.01 0.20 0.13 0.23 0.18 |
% 0.07 0.28 0.03 0.29 0.16 0.19 0.41 0.33 0.19 0.13 0.27 0.13 0.21 0.13 0.28 0.08 0.26 0.23 0.04 0.17 0.10 0.22 0.16 |
0.71 0.93 2.33 1.10 0.56 1.53 0.85 1.15 0.73 1.70 1.53 1.46 1.33 1.39 0.64 0.50 0.46 1.00 0.25 1.17 1.30 1.04 1.12 |
126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 |
% 0.03 0.15 0.13 0.10 0.20 0.05 0.08 0.27 0.17 0.25 0.14 0.15 0.21 0.18 0.12 0.12 0.13 0.07 0.25 0.07 0.17 0.17 0.03 |
% 0.04 0.19 0.09 0.10 0.18 0.20 0.04 0.33 0.22 0.38 0.08 0.08 0.16 0.11 0.05 0.12 0.10 0.03 0.19 0.04 0.15 0.19 0.04 |
0.75 0.80 1.44 1.00 1.11 0.25 2.00 0.82 0.77 0.66 1.75 1.87 1.31 1.63 2.40 1.00 1.30 2.33 1.31 1.75 1.13 0.89 0.75 |
*No. of case, 148; range, 0.21 to 2.66; mean ratio,
1.28; approximate ratio, 5:4; x 2
test, a + 0.01 df (n) – 6; observed value of x2, 6.852; value of x2, 16.812.
However, the alcohol levels of the spinal fluid, brain tissue, liver, or serum are in a relatively constant ratio with the alcohol concentration in the blood. This is not so with urine levels of alcohol. Because of this, a constant controversy has existed as to the reability of computing blood alcohol levels determined from urine specimens.
Many investigators, in the
assumption that a sufficiently definite relationship between blood and urine
alcohol concentrations exists, have stated that the chemical test of urine can
furnish a reliable measure of the degree of alcoholic influence. A number of them have even established a
definite blood-urine alcohol ratio.
It is evident that this ratio, although all of the ones reported are more or less of the same magnitude, may vary widely from the average in the individual case, but apparently the extent of the possible errors involved has not been realized by many investigators. At the present time urine, as a sole specimen for alcohol determinations, is used in many communities.
The present study was conducted in the hope of pointing again to be magnitude of the errors inherent in such a practice. Selected blood and urine specimens were collected from 240 human autopsy cases. Of these, 148 specimens were found to be positive for alcohol content in blood, urine, or both. The conclusions in this study are based on the analysis of these 148 cases.
EXPERIMENTAL
The technic used for the determination of alcohol levels in this study is the one suggested by Muehlberger12.
The
blood specimens were drawn directly from the right ventricle of the in situ
heart. Sodium fluoride (100 mg. Per 10 ml.) was
used as the
preservative. Urine specimens
were collected directly
BLOOD ALCOHOL
LEVELS CALCULATED FROM URINE VALUES USING A CONVERSION FACTORS OF 1.28:1
|
Case No. |
Urine |
Calculated Blood Level C |
Observed Blood Level O |
C-O |
Case No. |
Urine |
Calculated Blood Level C |
Observed Blood Level O |
C-O |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 |
% 0.10 0.17 0.20 0.16 0.22 0.30 0.08 0.36 0.33 0.19 0.10 0.14 0.08 0.23 0.13 0.21 0.26 0.21 0.10 0.10 0.09 0.42 0.07 0.14 0.16 0.47 0.29 0.20 0.18 0.26 0.32 0.31 0.30 0.14 0.13 0.13 0.35 0.13 0.17 0.35 0.25 0.19 |
% 0.08 0.13 0.16 0.12 0.17 0.23 0.06 0.28 0.26 0.15 0.08 0.11 0.06 0.18 0.10 0.16 0.20 0.16 0.08 0.08 0.07 0.33 0.05 0.11 0.12 0.37 0.23 0.16 0.14 0.20 0.25 0.24 0.23 0.11 0.10 0.10 0.27 0.10 0.13 0.27 0.20 0.15 |
% 0.05 0.12 0.23 0.12 0.23 0.23 0.18 0.20 0.19 0.18 0.06 0.13 0.04 0.31 0.19 0.21 0.24 0.17 0.08 0.04 0.09 0.22 0.03 0.11 0.09 0.39 0.24 0.15 0.13 0.28 0.30 0.25 0.29 0.08 0.10 0.09 0.29 0.06 0.10 0.25 0.16 0.16 |
+0.03 +0.01 -0.07 0.00 -0.06 0.00 -0.12 +0.08 +0.07 -0.03 +0.02 -0.02 +0.02 -0.13 -0.09 -0.05 -0.04 -0.01 0.00 +0.04 -0.02 +0.11 +0.02 0.00 +0.03 -0.02 -0.01 +0.01 +0.01 -0.08 -0.05 -0.01 -0.06 +0.03 0.00 +0.01 -0.02 +0.04 +0.03 +0.02 +0.04 -0.01 |
43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 |
% 0.15 0.28 0.34 0.09 0.19 0.19 0.25 0.10 0.40 0.05 0.39 0.24 0.14 0.17 0.12 0.30 0.25 0.07 0.26 0.18 0.27 0.13 0.33 0.22 0.38 0.22 0.16 0.12 0.20 0.14 0.37 0.30 0.27 0.10 0.04 0.03 0.32 0.20 0.16 0.03 0.34 0.15 |
% 0.12 0.22 0.27 0.07 0.15 0.15 0.20 0.08 0.31 0.04 0.30 0.19 0.11 0.13 0.09 0.23 0.20 0.05 0.20 0.14 0.21 0.10 0.26 0.17 0.30 0.17 0.12 0.09 0.16 0.11 0.29 0.23 0.21 0.08 0.03 0.02 0.25 0.16 0.12 0.02 0.27 0.12 |
% 0.09 0.19 0.40 0.15 0.18 0.14 0.24 0.12 0.27 0.03 0.31 0.22 0.08 0.12 0.08 0.18 0.16 0.04 0.19 0.19 0.18 0.11 0.36 0.15 0.23 0.18 0.10 0.08 0.16 0.10 0.32 0.20 0.17 0.10 0.06 0.02 0.30 0.18 0.10 0.14 0.41 0.09 |
+0.03 +0.03 -0.13 -0.08 -0.03 +0.01 -0.04 -0.04 +0.04 +0.01 -0.01 -0.03 +0.03 +0.01 +0.01 +0.05 +0.04 +0.01 -0.05 +0.03 -0.01 -0.10 +0.02 +0.07 -0.01 +0.02 +0.01 0.00 +0.01 -0.03 +0.03 +0.04 -0.02 -0.03 0.00 -0.05 -0.02 +0.02 -0.02 -0.12 -0.14 +0.03 |
Table 2 - Continued
|
Case No. |
Urine |
Calculated Blood Level C |
Observed Blood Level O |
C-O |
Case No. |
Urine |
Calculated Blood Level C |
Observed Blood Level O |
C-O |
|
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 |
% 0.16 0.33 0.31 0.49 0.22 0.38 0.22 0.12 0.25 0.22 0.10 0.05 0.24 0.37 0.18 0.23 0.10 0.30 0.05 0.26 0.07 0.32 0.09 0.29 0.35 0.38 0.14 0.22 0.41 0.19 0.28 0.18 |
% 0.12 0.26 0.24 0.38 0.17 0.30 0.17 0.09 0.20 0.17 0.08 0.04 0.19 0.29 0.14 0.18 0.08 0.23 0.04 0.20 0.05 0.25 0.07 0.23 0.27 0.30 0.11 0.17 0.32 0.15 0.22 0.14 |
% 0.06 0.22 0.25 0.45 0.17 0.24 0.24 0.08 0.24 0.23 0.10 0.03 0.22 0.37 0.13 0.17 0.04 0.29 0.07 0.28 0.03 0.29 0.16 0.19 0.41 0.33 0.19 0.13 0.27 0.13 0.21 0.13 |
+0.06 +0.04 -0.01 -0.07 0.00 +0.06 -0.07 +0.01 -0.04 -0.06 -0.02 +0.01 -0.03 -0.08 +0.01 +0.01 +0.04 -0.06 -0.03 -0.08 +0.02 -0.04 -0.09 +0.04 -0.14 -0.03 -0.08 +0.04 +0.05 +0.02 +0.01 +0.01 |
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 |
% 0.18 0.04 0.12 0.23 0.01 0.20 0.13 0.23 0.18 0.03 0.15 0.13 0.10 0.20 0.05 0.08 0.27 0.17 0.25 0.14 0.15 0.21 0.18 0.12 0.12 0.13 0.07 0.25 0.07 0.17 0.17 0.03 |
% 0.28 0.08 0.26 0.23 0.04 0.17 0.10 0.22 0.14 0.02 0.12 0.10 0.08 0.16 0.04 0.06 0.21 0.13 0.20 0.11 0.12 0.16 0.14 0.09 0.09 0.10 0.05 0.20 0.05 0.13 0.13 0.02 |
% 0.28 0.08 0.26 0.23 0.04 0.17 0.10 0.22 0.16 0.04 0.19 0.09 0.10 0.18 0.20 0.04 0.33 0.22 0.38 0.08 0.08 0.16 0.11 0.05 0.12 0.10 0.03 0.19 0.04 0.15 0.19 0.04 |
% -0.14 -0.05 -0.17 -0.05 -0.03 -0.01 0.00 -0.04 -0.02 -0.02 -0.07 +0.01 -0.02 -0.02 -0.16 +0.02 -0.12 -0.09 -0.18 +0.03 +0.04 0.00 +0.03 +0.04 -0.03 0.00 +0.02 +0.01 +0.01 -0.02 -0.06 -0.02 |
from
the urinary bladder. Blood and urine
from the same autopsy case were analyzed simultaneously.
The
results obtained from this study are shown in Tables 1, 2, and 3. A urine-blood alcohol ratio was determined
in each case. These varied in a range
of 0.21 to 2.66. The average ratio was
found to be 1.28:1; using it as a conversion factor, a “blood alcohol level”
was calculated from the urine value in each case. A comparison between the determined (true) blood alcohol level
and the blood alcohol level calculated from the corresponding urine value is
shown in Table 2.
Results
which were within 0.02 Gm. Per 100 ml. of each other were insignificant
differences (and within our experimental limits); they were, therefore,
considered to correspond. In 32 (21.5%)
of the 148 cases studied, the blood alcohol concentration calculated from the
urine level exceeded the actual value observed in the blood. In 51 cases (34.5%) the calculated value was
lower than that observed, and in 65 cases (44%) the values corresponded.
Table
3 shows the results obtained when the blood alcohol level was calculated for
each case from the corresponding urine value by means of the conversion factor
of 1.25:1 still actually used in some jurisdictions (Wisconsin, Washington,
D.C., Puerto Rico, New Hampshire, and California) for this purpose. In this instance, the results were as
follows:
1.
In
39 cases (26.5%) the calculated value was higher than the observed blood level.
2.
In
49 cases (33%) the calculated value was lower than that observed.
3.
In
60 cases (40.5%) the values corresponded.
BLOOD ALCOHOL LEVEL CALCULATED FROM URINE VALUES USING A CONVERSION
FACTOR OF 1.25:1
|
Case No. |
Urine |
Calculated Blood Level C |
Obseerved Blood Level O |
C-O |
Case No. |
Urine |
Calculated Blood Level C |
Observed Blood Level O |
C-O |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 |
% 0.10 0.17 0.20 0.16 0.22 0.30 0.08 0.36 0.33 0.19 0.10 0.14 0.08 0.23 0.13 0.21 0.26 0.21 0.10 0.10 0.09 0.42 0.07 0.14 0.16 0.47 0.29 0.20 0.18 0.26 0.32 0.31 0.30 0.14 0.13 0.13 0.35 0.13 0.17 0.35 0.25 0.19 |
% 0.08 0.14 0.16 0.13 0.18 0.24 0.06 0.29 0.26 0.15 0.08 0.11 0.06 0.18 0.10 0.17 0.21 0.17 0.08 0.08 0.07 0.34 0.06 0.11 0.13 0.38 0.23 0.16 0.14 0.21 0.26 0.25 0.24 0.11 0.10 0.10 0.28 0.10 0.14 0.28 0.20 0.15 |
% 0.05 0.12 0.23 0.12 0.23 0.23 0.18 0.20 0.19 0.18 0.06 0.13 0.04 0.31 0.19 0.21 0.24 0.17 0.08 0.04 0.09 0.22 0.03 0.11 0.09 0.39 0.24 0.15 0.13 0.28 0.30 0.25 0.29 0.08 0.10 0.19 0.29 0.06 0.10 0.25 0.16 0.16 |
+0.03 +0.02 -0.07 +0.01 -0.05 +0.01 -0.12 +0.09 +0.07 -0.03 +0.02 -0.02 +0.02 -0.13 -0.09 -0.04 -0.03 0.00 0.00 +0.04 -0.02 +0.12 +0.03 0.00 +0.04 -0.01 -0.01 +0.01 +0.01 -0.07 -0.04 0.00 -0.05 +0.03 0.00 +0.01 -0.01 +0.04 +0.04 +0.03 +0.04 -0.01 |
43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 |
% 0.15 0.28 0.34 0.09 0.19 0.19 0.25 0.10 0.40 0.05 0.39 0.24 0.14 0.17 0.12 0.30 0.25 0.07 0.26 0.18 0.27 0.13 0.33 0.22 0.38 0.22 0.16 0.12 0.20 0.14 0.37 0.30 0.27 0.10 0.04 0.03 0.32 0.20 0.16 0.03 0.34 0.15 |
% 0.12 0.22 0.27 0.07 0.15 0.15 0.20 0.08 0.32 0.04 0.31 0.19 0.11 0.14 0.10 0.24 0.20 0.06 0.21 0.14 0.22 0.10 0.26 0.18 0.30 0.18 0.13 0.10 0.16 0.11 0.30 0.24 0.22 0.08 0.03 0.02 0.26 0.16 0.13 0.02 0.27 0.12 |
% 0.09 0.19 0.40 0.15 0.18 0.14 0.24 0.12 0.27 0.03 0.31 0.22 0.08 0.12 0.03 0.18 0.16 0.04 0.19 0.19 0.18 0.11 0.36 0.15 0.23 0.18 0.10 0.08 0.16 0.10 0.32 0.20 0.17 0.10 0.06 0.02 0.30 0.18 0.10 0.14 0.41 0.09 |
+0.03 +0.03 -0.13 -0.08 -0.03 +0.01 -0.04 -0.04 +0.05 +0.01 0.00 -0.03 +0.03 +0.02 +0.02 +0.06 +0.04 +0.02 +0.02 -0.05 +0.04 -0.01 -0.10 +0.03 +0.07 0.00 +0.03 +0.02 0.00 +0.01 -0.02 +0.04 +0.05 -0.02 -0.03 0.00 -0.04 -0.02 +0.03 -0.12 -0.14 +0.03 |
TABE 3 - Continued
|
Case No. |
Urine |
Calculated Blood Level C |
Observed Blood Level O |
C-O |
Case No. |
Urine |
Calculated Blood Level C |
Observed Blood Level O |
C-O |
|
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 |
% 0.16 0.33 0.31 0.49 0.22 0.38 0.22 0.12 0.25 0.22 0.10 0.05 0.24 0.37 0.18 0.23 0.10 0.30 0.05 0.26 0.07 0.32 0.09 0.29 0.35 0.38 0.14 0.22 0.41 0.19 0.28 0.18 |
% 0.13 0.26 0.25 0.39 0.18 0.30 0.18 0.10 0.20 0.18 0.08 0.04 0.19 0.30 0.14 0.18 0.08 0.24 0.04 0.21 0.06 0.26 0.07 0.23 0.28 0.30 0.11 0.18 0.33 0.15 0.22 0.14 |
% 0.06 0.22 0.25 0.45 0.17 0.24 0.24 0.08 0.24 0.23 0.10 0.03 0.22 0.37 0.13 0.17 0.04 0.29 0.07 0.28 0.03 0.29 0.16 0.19 0.41 0.33 0.19 0.13 0.27 0.13 0.21 0.13 |
+0.07 +0.04 0.00 -0.06 +0.01 +0.06 -0.06 +0.02 -0.04 -0.05 -0.02 +0.01 -0.03 -0.07 +0.01 +0.01 +0.04 -0.05 -0.03 -0.07 +0.03 -0.03 -0.09 +0.04 -0.13 -0.03 -0.08 +0.05 +0.06 +0.02 +0.01 +0.01 |
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 |
% 0.18 0.04 0.12 0.23 0.01 0.20 0.13 0.23 0.18 0.03 0.15 0.13 0.10 0.20 0.05 0.08 0.27 0.17 0.25 0.14 0.15 0.21 0.18 0.12 0.12 0.13 0.07 0.25 0.07 0.17 0.17 0.03 |
% 0.14 0.03 0.10 0.18 0.01 0.16 0.10 0.18 0.14 0.02 0.12 0.10 0.08 0.16 0.04 0.06 0.22 0.14 0.20 0.11 0.12 0.17 0.14 0.10 0.10 0.10 0.06 0.20 0.06 0.14 0.14 0.02 |
% 0.28 0.08 0.26 0.23 0.04 0.17 0.10 0.22 0.16 0.04 0.19 0.09 0.10 0.18 0.20 0.04 0.33 0.22 0.38 0.08 0.08 0.16 0.11 0.05 0.12 0.10 0.03 0.19 0.04 0.15 0.19 0.04 |
-0.14 -0.05 -0.16 -0.05 -0.03 -0.01 0.00 -0.04 -0.02 -0.02 -0.07 +0.01 -0.02 -0.02 -0.16 +0.02 -0.11 -0.08 -0.18 +0.03 +0.04 +0.01 +0.03 +0.05 -0.02 0.00 +0.03 +0.01 +0.02 -0.01 -0.05 -0.02 |
The
use of urine for the determination of the alcoholic content can be of value
particularly in those instances where no other specimen is available; however,
this practice can be hazardous because of the variability of urine due to
factors which can be detrimental to the proper interpretation of the
results. This fact was pointed out by
Haagard and his associates5 who stated that, although the
concentration of alcohol in ureteral urine is proportional to that
simultaneously in the blood, the concentration in the bladder may not show this
correspondence since ureteral urine is mixed immediately with that already
accumulated in the bladder. They
concluded that reliable estimates of the alcohol concentration in the blood may
be made from that of urine only after the first hour following the ingestion of
alcohol by having the subject completely empty his bladder, discarding that
specimen, and examining another specimen voided 30 min. later. However, although most people do not object
to the first sample of urine, it is frequently impossible to secure a second
specimen 30 min. later. Because of
this, and in the omission of any specifications to that respect in most state
laws, usually the first (and only) specimen is analyzed and the blood alcohol
level is calculated from the urine alcohol value obtained. Also, as Ellerbrook2 has shown,
even with a 30-min. interval, the urine alcohol value obtained from the second
specimen does not always correspond with the blood level. Morgan10 and Kaye and Cardona9
concur with Ellerbrook. Since the blood
alcohol concentration thus obtained can be grossly inaccurate, as further
evidence by our study, any conclusions drawn from results thus obtained are
questionable and thus unjustified.
Apparently the constant variation
in the composition of urine as a source of errors in the calculation of the
blood alcoholic content from urine values has not been fully realized, as can
be inferred by the number of communities and investigators that condone, and
even encourage, this practice of conversion of values.
The
variations encountered in the relationship between the alcohol level in blood
and that in urine in living subjects may depend upon: (1) the amount of urine present in the bladder at the time of
alcohol ingestion5, (2) the frequency of micturition between alcohol
ingestion and the collection of the urine specimen3, (3)
the stage of the alcohol absorption at the time of collection1,
* (4) the permeability of the urinary
bladder mucosa to alcohol to and from the blood5, 11, 13 and (5)
the possible influence of the specific gravity of urine on the
urine-blood alcohol ratios4, 6, 7.
With
deceased subjects, the extent of the possible errors involved is even greater
since no control of conditions is possible.
In most of the cases there is no history available with regard to the
ingestion of alcohol, the frequency of voiding, or any other related
circumstance prior to death.
In
our experience with 148 autopsy cases, the difficulty of obtaining a constant
relationship between the concentration of alcohol in blood and in urine was
demonstrated by the wide range of the individual ratios of urine blood levels.
i.e., from a ratio of 0.21:1 to that of 2.66:1. We obtained an average ratio of 1.28:1, which is in accordance
with most of the values previously reported by other investigators. The magnitude of the errors that can be
incurred when such a ratio is used to calculate the blood alcohol level from
the urine determination can be appreciated in Tables 2 and 3. This is not a hypothetical situation; the
figures listed in these tables belong to actual cases, and the calculated blood
alcohol levels in Table 3 were obtained by means of the same accepted
conversion factor used in many communities.
The
implications of such a practice, as inferred from these results, are
clear. An error on a blood alcohol
concentration which is near one of the critical levels may profoundly influence
the medical and the legal interpretation of the results with the obvious
consequences in a court of law.
1.
A
Report of the Committee on Test for Intoxication. National Safety Council, 1953.
2.
Ellerbrook,
L.D., and Van Gaasbeek, C.B.: The
reliability of chemical tests for alcoholic
Intoxication. J.A.M.A., 122: 996-1002, 1943.
3.
Forney,
R.B., Hughes, F.W., Harger, R.N., and Richards, A.B.: Alcohol distribution in the
Vascular system. Quart. J.. Stud. Alcohol, 25: 205-217, 1964.
4.
Haggard,
H.W., and Greenberg, L.A.: Studies in
the absorption distribution and elimination
of ethyl alcohol. J. Pharmacol. & Exper. Therap., 52: 137-178, 1934.
5.
Haggard,
H.W., Greenberg, L.A., Carroll, R.P., and Miller, D.P.: The use of urine in the
Chemical test for
intoxication: possible errors and their avoidance. J.A.M.A., 115:
1680-1683, 1940.
6.
Jetter,
W.W.: A critical survey of various chemical methods for determining the alcohol
Content of body fluids and
tissue with their physiological and medicolegal significance.
Quant. J. Stud. Alcohol, 2: 512-543, 1941.
__________
* Before alcohol can be excreted through the kidney
it must first be absorbed into the blood stream. Thus, during the process of drinking, the concentratiuon of
alcohol in the urine lags behind that in blood, and it is not until absorption
has been complete (approximately 1 hr. after the first drink) that equilibrium
is established and the urine alcohol concentration “parallels” the blood
alcohol concentration11.
7.
Kaye,
S.: Observations on the determination
of ethyl alcohol. Richmond: Thesis,
Depart-
ment of Pharmacology,
Medical College of Virginia, 1955.
8.
Kaye,
S.: Alcohol and its effects on
man. Med. Times, 88: 1142-1960.
9.
Kaye,
S., and Cardona, E.L.: Some questions
in the evaluation of the blood alcohol level
in man. Proceedings of the 4th
International Conference on Alcohol and Traffic
Safety. Indianapolis: Indiana University, 1965.
10.
Morgan,
W.H.D.: Concentrations of alcohol in samples of blood and urine taken in the
same time. J. Forensic Sci. Soc., 5: 15-21, 1965.
11.
Moritz,
A.R., and Jetter, W.W.: Antemortem and
postmortem diffusion of alcohol
through the mucosa of the
bladder. Arch. Path., 33: 939-948, 1942.
12.
Muehlberger,
C.W.: In Levinson and McFate:
Clinical Laboratory Diagnosis,
Ed. 6. 1961, p. 1197.
13. Vottz,
W., Baudrexel, A., and Dietrich, W.:
Arch. J. ges. Physiol., 145:
186, 1912.