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

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Verner/Schneider/Gebel/Panning/Wiese/Tröger/Breitmeier,
Blood ethanol concentrations and inebriation symptoms following percutaneous ethanol injection
therapy (PEIT) carried out on patients suffering from hepatocellular carcinoma
patients after percutaneous ethanol injection therapy and unexpectedly high peak BECs are
probable with a high risk for unexpected iatrogenic intoxications. They still can explain
our early clinical signs after clinical examination of systemic alcohol toxicity after PEI,
such as drowsiness, euphoria, slurring and lalling speech, nausea, vomiting, smell of alcohol,
and desorientation, because of the flooding effect while high amounts of ethanol flow
off into the brain and impairs the central nervous system. The variable release of ethanol
from the tumor can be explained by changes of the vascularisation and sudden destruction
of cell barriers. Apart from the experience of the responsible therapist, consistency, vascularisation,
size of the tumour and the stage of liver cirrhosis, extratumoral alcohol distribution
was also influenced by injection pressure and the proper position of the injection needle.
Insofar apart from the injected amount of ethanol its distribution during and after PEI
is of importance. Even small amounts of ethanol injected wrongly and hence bypassing the
tumour can through direct systemic diversion join the brain circulation and can subsequently
produce significant ethanol concentrations and related deficiencies. As a result of
our research, blood alcohol concentrations of more than 2.00 % which in this way were
never expected by the therapists, and the clinical deficiencies, the therapists decided to
drastically reduce the amount of ethanol injected per session. Regarding the proven blood
alcohol concentration and the deficiencies chronic liver patients should be monitored in relation
to possible risks of anaesthesia. Such a monitoring can be very reliable through measuring
breath alcohol concentration during therapy as well as afterwards on the ward [35].
The aim of a gentle anesthetic procedure in patients with hepatic insufficiency is the selection
of an anesthetic procedure which does not interfere negatively with liver function
and oxygen supply of the organ. The synthetic opiate fentanil influences neither liver circulation
nor pharmacokinetics [36]. With propofol only a slight slowdown of metabolism
can be observed. The half-time of propofol is between 34 and 64 minutes, the effectiveness
4-6 minutes. Anesthesia was started with a maximum of 2.0 mg/kg body weight and maintained
with 6mg/kg body weight. Fentanil has a half-time of 2-4 hours and an effectiveness
of 10 minutes. Respiratory depression continues for about 60-90 minutes. Fentanil was
used with a minimum dose of about 0.005 mg/kg body weight. For optimal care of the
patient only concentrations at the lowest possible level of normally used amounts were
administered. As a result after PEI no patient under the influence of short-acting narcotics
suffered an unnecessary extension of anaesthesia. Without having made blood level measurements
of anaesthetics it turned out that patients at the time of medical examination at
least 2 hours after PEI suffered no effects of anesthesia anymore and therefore any recorded
deficiencies can be seen as being solely the result of ethanol injection.
According to NORBERG et al. [37] the rate-limiting step in oxidation is conversion of
ethanol into acetaldehyd by cytosolic alcohol dehydrogenase (ADH), which has a low
Michaelis-Menten constant (Km) of 0.05–0.1 g/l. When a moderate dose is ingested,
zero-order elemination operates for a large part of the blood-concentration time course.
As can be seen in figure 1 the BECs do probably in some cases not follow a kinetic of
zero or any other order if the tumour release ethanol into hepatic veins. In other cases a
kinetic of zero order, after the maximum BEC an immediate and straight decline was to
be shown (Fig. 1). Futhermore in a few cases a steady state or rather a biphasic time
course for elemination were seen. In our opinion it can be suggested, that at the time of
steady state or biphasic time course after maximum of blood ethanol concentration there
is an equilibrium after the end of injection and maximum of BEC between the time-in-
BLUTALKOHOL VOL. 42/2005