Side effects
In general, the side effects of local anesthetics are considered very low compared to the side effects of general anesthesia. Nevertheless, it is important to mention that local anesthetics are derived from cocaine and therefore have a certain (albeit minimal) addictive potential on the one hand, and may have certain side effects on the other. These include, above all, heart problems.
The heart may beat more slowly (bradycardia), while at the same time some patients experience an increasingly rapid and irregular heartbeat (tachycardia). In general, this can lead to cardiac arrhythmia and problems with heart conduction. Some patients may also experience cramps and loss of consciousness, even fainting. In addition, some patients show strong allergic reactions, which can range from itching and vomiting to a state of shock. Therefore, it is important to pay attention to possible symptoms after treatment with a local anesthetic and to inform a doctor if symptoms become more severe.
Contraindications
There are various contraindications for which patients should not receive local anesthetics. This is mostly due to the fact that local anesthetics are often coupled with adrenaline, as adrenaline causes the blood vessels to constrict and not as much blood reaches the area where the local anesthetic is effective. This is, of course, very desirable for smaller operations, as one wants to avoid unnecessary blood flow. Patients with known allergic reactions or heart problems should still not be given local anesthetics, as this can increase the problems. In addition, local anesthetics should never be used in the finger, toe, nose or penis area, as this can reduce the blood flow so much that parts of the tissue die off.
Advantages and disadvantages
Compared to conventional general anesthesia, local anesthesia offers numerous advantages. The human body is considerably less burdened, since the anaesthetic does not affect the entire circulation, but only the desired nerve tracts, i.e. locally limited. Thus, unforeseeable events, such as a heart attack, stroke or post-operative intestinal paralysis, occur much less frequently.
Typical ventilation errors can be virtually ruled out with local anesthesia because patients breathe on their own. Serious side effects of general anesthesia, such as the danger of malignant hyperthermia, are hardly ever observed. In addition, patients recover much faster after a local anesthesia: they are allowed to leave the recovery room after a short time, require less time-consuming monitoring and can get up on their own much earlier.Nevertheless, there are disadvantages and risks even with local anesthesia.
For example, it requires a significantly higher time expenditure. Particularly in the case of spinal cord anaesthesia, some time can pass between the correct injection and the fully deployed anaesthesia. So if it has to be done quickly and it is an emergency, a general anaesthetic is often the better choice.
In addition, the success depends heavily on the skill, experience and ability of the doctor. An incorrectly placed needle can sometimes result in incomplete anesthesia. For many anxious or insecure patients, the idea of experiencing a surgical procedure in full consciousness is rather daunting.
Therefore, an empathetic educational conversation before the operation is very important. During the conversation, the doctor should describe the exact procedure and prepare the patient e.g. for any noises that may occur. Patients are often given a light sedative before the operation. This way they are conscious during the operation, but afterwards they often cannot remember the operation at all or only incompletely, or even ‘oversleep’.
