Introduction
TIVA stands for Total Intravenous Anaesthesia and describes an anaesthesia that is only performed with drugs that are administered directly into the vein. This means that no gaseous medications administered to the patient via the respiratory tract (inhaled narcotics) are used, as is often the case with general anesthesia. Anaesthesia using both gaseous and intravenous drugs is called balanced anaesthesia. In the TIVA, the various drugs are administered via a programmable syringe pump to ensure a constant supply throughout the anaesthesia.
Indications of a TIVA
A TIVA provides a quasi equivalent alternative to Balanced Anesthesia. It is used for short operations, but can also be used for longer operations. The TIVA is particularly well suited for outpatient operations.
In an outpatient procedure, the patient can go home on the day of the operation. An overhang, i.e. a prolonged duration of the effect of the medication is almost impossible with the TIVA. The patient can therefore be discharged home on the same day without any worries.
The TIVA is also used in emergency medicine when the possibility of using gas is not available. Furthermore, the TIVA is well suited for patients with malignant hyperthermia. This is a disease that does not present any problems in everyday life, but can be very dangerous under anesthesia.
Various hereditary defects cause an accumulation of too much calcium in the muscle cells. Calcium causes the muscle cells to contract. If there is too much of it, the muscle cell contracts permanently and overheating (hyperthermia) occurs.
A TIVA can also be used particularly well in patients with increased intracranial pressure. The human skull is a space limited by the bones. If swelling or fluid accumulation occurs here, for example, the pressure in this limited space increases, which can lead to damage to the brain cells and important centers in the brain.
Which drugs are used?
Basically an anaesthetic consists of three components of drugs: Analgesics (painkillers), hypnotics (“sleeping pills“) and muscle relaxants (drugs to relax muscles). It is important for the drugs used in TIVA to have a short half-life. This means that they are quickly broken down in the body.
This means that the anaesthesia can be better controlled and the effect of the drugs quickly subsides after the operation. The most commonly used hypnotic agent in TIVA is Propofol. It ensures a fast sleep with a pleasant falling asleep and waking up.
It is also one of the drugs that lowers the cerebral pressure. It also counteracts the nausea that can occur after anesthesia. A disadvantage of propofol is that it can cause a strong burning sensation when injected into the vein.
This can be counteracted by administering a painkiller into the vein beforehand. Propofol also lowers blood pressure and the drive to breathe. To a certain extent, this is not a problem, but if the blood pressure is lowered too much, this must be counteracted with other drugs.
Alternatively, etomidate can also be used as a hypnotic. It has the advantage that, unlike propofol, it has fewer effects on the cardiovascular system. Another hypnotic used is ketamine.
This drug has the advantage that it also relieves pain. It is preferably used in emergency medicine, but is also suitable for TIVA. The next component of anaesthesia is analgesia.
Here very strong analgesics are used, which are also given through the vein. The two opioids fentanyl or remifentanil are usually used. These are quickly broken down in the body.
The third component is the muscle relaxants. They are necessary if a patient is to be ventilated with a machine via a tube in the trachea during anesthesia. However, there are also ventilation methods where no muscle relaxation is necessary. Here, the patient’s independent breathing is partially maintained and is supported by a machine. This topic might also be of interest to you:
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