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Propofol is the name for an organic chemical compound belonging to the group of phenols and a drug made from this substance. The action of Propofol has a very intense influence on the central nervous system. Its action causes effects such as anesthesia, sedation or – depending on the dose – complete loss of consciousness. The main producer of Propofol on the Polish market is B. Braun, which produces preparations in the form of Propofol-Lipuro injectable emulsions.
Propofol – how does it work?
When administered intravenously as an injection, Propofol travels through the tissues and is immediately metabolized. The place of its absorption is the liver, where even more than 90% of this substance is absorbed. Within 30-60 seconds after administration, Propofol induces unconsciousness. This is the time the blood travels from your arm (where the injection was given) to the brain. The effect of Propofol lasts – with just one dose – for about 5 minutes. After this time, the substance is metabolized into the inactive propofol glucuronate and hydroquinone. As metabolites, the drug is excreted from the body through the kidneys. As a result, the patient wakes up completely within 5 minutes after administering one dose of Propofol. The half-life of the effects of Propofol is 30 to 60 minutes after the injection of one dose.
Propofol interacts with plasma proteins in almost 100%. Propofol infusions may be administered for a period from several hours to several days. After stopping the infusion for 10 hours, the plasma concentration of Propofol is halved in less than 10 minutes. Exceeding the 50% concentration threshold is tantamount to awakening the patient and regaining consciousness by him. In the case of infusions lasting 10 days, the elimination time takes 1-3 days. The duration of the effect of Propofol does not depend on gender. However, the elderly are more sensitive to its impact.
Propofol dosage
For general anesthesia, Propofol is administered at a dose of 1,5-2,5 mg per kilogram of body weight. The dose for the elderly is slightly lower. For sedation, infusions of 0,3-4 mg per kilogram body weight are used.
Indications and contraindications to the use of Propofol
Propofol is used, inter alia, to induce anesthesia during unpleasant or extremely painful diagnostic procedures. In such situations, Propofol is often administered together with other substances: opioids and benzodiazepines. In addition, Propofol is used during procedures in which it is necessary to use general anesthesia. Propofol is used both in outpatient practice and in intensive care units.
In the case of sedation, Propofol is used in people over 16 years of age. As a form of general anesthesia, it is used in infants over 1 month of age.
People who are not recommended to use Propofol include people who are allergic to this substance or any of the additional ingredients. Propofol is also not used in obstetrics or during cesarean section surgery (due to the possibility of absorption of the substance by the child). It is not recommended to use Propofol or take special precautions in the case of newborns, people with heart failure, ischemic heart disease, hypovolaemia, respiratory problems, patients with epilepsy, liver failure, kidney failure, increased intracranial pressure, the elderly and people at increased anesthetic risk. In the above cases, alternate or other forms of anesthesia are used.
Side effects of Propofol
The most important side effects caused by Propofol include:
- pain,
- apnea, hyperventilation,
- involuntary movements, spasms, muscle tremors,
- drop in blood pressure
- increase in the concentration of histamine in the blood,
- decrease in cardiac output,
- reflex tachycardia,
- respiratory depression,
- during awakening: hallucinations, hallucinations.
In patients whose blood levels of carbon dioxide are low, the following side effects of taking Propofol may also occur:
- increase in the resistance of the cerebral vascular bed,
- slowing down the metabolism of the central nervous system,
- reducing the level of oxygen consumption,
- increase in intracranial pressure.