Blutalkohol 2005 - BADS (Bund gegen Alkohol und Drogen im ...

Breitmeier/Verner/Albrecht/Fieguth/Geerlings/Kleemann/Panning/Gebel/Tröger,
Arteriovenous differences (A-V differences) by patients with a hepatocellular carcinoma
in relation to percutaneous ethanol injection therapy (PEIT)
peripheral system, it is disseminated through the venous system. Until reaching maximum
BAC, in theory arterial BAC should be higher than venous BAC. This could be experimentally
confirmed. Since the central venous blood compartment is reached after the
peripheral venous one, no major differences in BEC were to be expected, this was confirmed
by the respective results. During the elimination period an equilibrium regarding
BEC and the individual blood compartments came into being. Thereby a redistribution of
alcohol in particular from water carrying tissue into the blood vessel takes place so that no
differences in BEC of the respective blood compartments were expected; this could be
confirmed with the current results in good agreement with previous publications [19, 20, 21].
Under clinical conditions and as a consequence of that study, we strongly recommend to
draw arterial blood samples for determination of blood ethanol levels during intervention,
in order to avoid a potential underestimation of the peak ethanol levels and a deterioration
in the patient's condition, because blood alcohol concentrations vary significantly according
to the sampling site and especially under a large amount of injected ethanol up to
95.0 ml intoxications can likely occur.
With regard to legal considerations the blood compartment from which BEC is to be determined
is – based on the current research – of great importance, in particular when using
the determined arterial BEC as evidence in court, or for eventually necessary re-determination.
If, for example with a patient with recent alcohol intake and multiple injuries from
a traffic accident BEC were to be determined, then in accordance with the above mentioned
experiments a higher amount of alcohol would be measured in the arterial than in
the venous compartment. Subsequently under such circumstances the patient would be
legally disadvantaged when sentenced, contrary to the legal guideline “in dubio pro reo”.
It has to be stressed that for the individual taking of blood samples during alcohol injection
no exact time intervalls could be planned or adhered to, as the physician needed varying
amounts of time for each individual injection because the tumor had to be sonographically
readjusted or various breathing procedures were necessary to improve the representation of
the tumor. These intervalls were not calculable for us. Therefore we could not stick to exact
intervalls for taking blood samples, contrary to other publications.
Further studies are necessary to explain variabilities in the ethanol pharmakokinetics
with regard to alcohol resorption, distribution, and elimination especially by percutaneus
ethanol injection.
Summary
Percutaneous injection of ethanol (96 vol.%) into a liver tumor is one among several other alternative therapies
for irresectable hepatocellular carcinomas (HCC). The absence of any ethanol loss due to resorption deficits
or hepatic metabolism makes the injected amount of ethanol directly accessible to studies of its distribution between
different blood compartments. Where should the blood sample be drawn from to calculate the amount of
ethanol in the body? Blood samples from a peripheral vein, a central venous, and a radial artery catheter were
drawn from altogether 20 patients at definite time intervals during and immediately after the injection of ethanol.
The amount of injected ethanol ranged from 14.0 to 95.0 ml. The highest ethanol concentration was found at
1.47 g/kg in the radial artery, at 1.54 g/kg in the superior vena cava, and at 1.34 g/kg in the cubital veins. The
ethanol concentrations in the arterial blood samples were significantly higher than in the peripheral and central
venous blood samples during the time period until the maximum ethanol concentration was reached. These
differences disappeared in the elimination phase. Our results showed that the distribution of ethanol injected
directly into the HCC in patients with severe impairments of liver function parallels the distribution kinetics previously
shown for ethanol in animals and humans during intravenous injection and in healthy volunteers after oral
ingestion. In order to avoid a potential underestimation of the ethanol concentration under clinical conditions, be-
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BLUTALKOHOL VOL. 42/2005