Detoxification procedures are therapeutic methods of various medical specialties, especially toxicology and nephrology, which serve the withdrawal of toxic substances (toxins) from the bloodstream or the entire organism of the patient. The field of application of detoxification procedures extends over various areas, such as acute intoxication (poisoning) to permanent therapy for chronic kidney damage or chronic renal insufficiency. Especially in the case of acute intoxication with drugs, which is the most common form of intoxication in Germany, the various detoxification procedures serve as the means of choice. If the substances to be eliminated are the triggers of acute intoxication, the vital functions must first be secured. Subsequently, the detoxification procedures are applied. Detoxification procedures can be divided into two main groups: primary and secondary detoxification procedures. A primary detoxification procedure is characterized by the fact that it includes all the measures for resorption reduction (absorption reduction) of the ingested toxins and harmful substances. The choice of procedure depends on the site of toxin absorption, the properties of the toxin, the time interval between toxin absorption and the start of treatment, as well as the amount absorbed and the clinical condition of the patient. Thus, it can be concluded that the indication (indication for use) for primary and secondary toxin elimination or the use of antidotes requires an accurate assessment of the substance-specific toxicokinetics (toxin behavior in the body) and patient data.
Indications (areas of application)
- Uptake of a potentially lethal toxin dose at the start of therapy.
- A lower endogenous toxin clearance (endogenous toxin removal) than would be possible by exogenous removal (removal from outside the body)
- Presence of hepatic or renal insufficiency.
The procedures
Primary detoxification procedures
- Activated charcoal administration – this form of detoxification still plays an important role in the treatment of acute intoxications today, as the charcoal used has a high adsorption capacity (absorption capacity) due to its large surface area. The dose to be applied is directly dependent on the body weight. Thus, an unspecific binding of various substances can be guaranteed. It should be noted, however, that the administration of activated carbon is ineffective with organic solvents, acids, alkalis and salts. Furthermore, it should be avoided that activated charcoal is used after ingestion (ingestion by mouth) of corrosive substances, as this could make a perhaps necessary follow-up endoscopy to determine any mucosal damage impossible.
- Gastric lavage – this detoxification procedure is no longer considered the drug of choice for acute intoxication in most cases today, as it is associated with massive risks such as aspiration pneumonia (pneumonia caused by food components in the respiratory tract), cardiac arrhythmias, or water intoxication in children. Especially the influence on the cardiovascular system is based on flushing the stomach with 10 to 20 liters of water. Thus, this therapeutic measure is indicated only in the case of ingestion of large amounts of toxins and when activated charcoal is ineffective. However, on average, only 30% of the ingested toxin is adequately removed. Moreover, if loss of consciousness is imminent, intubation (artificial respiration) should be considered. Even non-cooperative patients should be intubated to prevent consequential damage caused by this.
- Induced vomiting – mechanical irritation of the throat or ingestion of ipecacuanha syrup may induce emesis. However, if the harmful substance ingested is a corrosive substance, vomiting may not be induced. However, it is problematic that the nausea can last for many hours.
Secondary detoxification procedures
Secondary detoxification refers to the measures taken to eliminate harmful substances from the bloodstream. The basic principle of secondary detoxification procedures is to accelerate the elimination of toxins from the organism.In order to select the secondary detoxification procedure, it is necessary to have detailed knowledge of the absorption kinetics (drug uptake), elimination, metabolism (drug degradation) and volume of distribution of the substance to be removed. The indication for extracorporeal elimination procedures should always be based on the clinical picture, additional neurologic examinations, and the presence of hazardous blood concentrations.
- Hemoperfusion – this secondary detoxification procedure represents an extracorporeal (outside the body) elimination procedure based on the principle of removing toxic substances from the blood using a specific adsorption system (toxin accumulation on a solid). Hemoperfusion is used for the removal of exogenous (externally supplied) toxins that cannot be adequately eliminated from the body by hemodialysis or hemofiltration. Example substances that can be removed from the bloodstream by hemoperfusion are theophylline (active substance used in asthma therapy) and the analgesic substance paracetamol.
- Plasma separation – by means of plasma separation can be filtered substances that have a defined size. Furthermore, the substances must be characterized by good protein binding and have a low volume of distribution. Digitoxin (toxin from the plant “foxglove”) can be named as the most important example substance. Plasma separation is also an extracorporeal procedure, so the given substance must be dissolved in plasma in large quantities. As with all extracorporeal detoxification procedures, the removal of the harmful substance is limited by a high protein binding.
- Hemodialysis – the principle of hemodialysis, which is primarily used in renal insufficiency (kidney damage), is based on the exchange of substances dissolved in fluid and located in one compartment (delimited space) with another compartment. Between these compartments there is a semi-permeable membrane so that only certain substances can cross this membrane. For the application of hemodialysis it is necessary to know that the elimination of the substances depends on the water solubility of the pollutants. Hemodialysis can be performed by various methods. Most often this form of dialysis is performed using bicarbonate dialysis, but acetate buffer dialysis, hemofiltration and hemodiafiltration are also used. *
- Antidote administration – a so-called “antidote” is only known for about two percent of toxic substances, so this therapy is only important for a few intoxications. It is the antidote a specific toxicological antagonist (antagonist) of the harmful substance, which should lead to the inactivation of the harmful substance when administered correctly.
* The individual dialysis procedures are listed in a separate chapter.
