What drugs are used

The oldest local anesthetic is cocaine, which is now only known as a drug. Although it is no longer used in medicine, the current local anesthetics work in the same way. Bubivacaine, lidocaine, ropivacaine, prilocaine, procaine and some other substances are used.

The various drugs differ in their effectiveness, duration of action, time to onset and controllability. In dentistry, lidocaine in particular has proven to be effective. Which drug is used depends on the type and duration of the procedure and individual tolerance.

Risks and side effects

When used correctly and without the local anesthetic entering the bloodstream, the side effects are minor and much lighter than with a general anesthetic. Local intolerances and swelling are possible. In case of a known allergy, a different anaesthetic method should be chosen, as allergic reactions up to allergic shock are possible.

If the local anesthetic enters the bloodstream and is distributed throughout the body, the side effects increase depending on the concentration in the blood. Initially, dizziness, headaches, drowsiness and nausea are possible. A higher dose may cause coma and respiratory paralysis.

The local anaesthetics also have effects on the cardiovascular system. Blood pressure drops and the heart‘s ability to beat decreases. In addition, the heartbeat may slow down and the heart rhythm may be disturbed. In extreme cases, cardiovascular arrest may occur.Due to these possible side effects on the cardiovascular system, severe conduction disorders of the heart and decompensated cardiac fatigue are contraindications for a block anaesthesia. In this case the patient can be better controlled under general anesthesia.

Duration

The duration of a block anaesthesia depends on several factors. The different local anaesthetics have different durations of action. For short procedures, approximately less than one hour, a single administration of the local anesthetic is sufficient.

However, longer operations can also be performed under a block anaesthesia. For this purpose, the anaesthetist leaves a catheter in the anaesthetic area and can administer a further dose of local anaesthetic if necessary. Without further anaesthesia, the block anaesthesia lasts only a few hours.