Conduction anesthesia is a local anesthetic. As the nerves divide more and more away from the spinal cord, anesthesia in one place can numb any area farther from the body trunk. This form of anesthesia is especially useful for operations on the hands or forearms and also in dentistry. The affected person is awake and responsive during the procedure.
As in virtually all areas of medicine, the principle of anesthesia is to intervene as little as possible in bodily functions. Therefore, as a rule, the stunning method is chosen to be as minimal as possible for the planned procedure. If the purely local anesthesia is not sufficient, the line anesthesia is chosen. If this is also insufficient, a spinal anesthesia or even a general anesthetic is performed.
However, as long as a line anesthesia is sufficient to perform an operation on the arms, legs or teeth, this possibility should also be used. Especially in areas far away from the body, such as the wrist, a line anesthesia is recommended. Important here is good accessibility of the nerves concerned. Especially in older people who suffer more from the effects of general anesthesia, the line anesthesia offers great advantages, since this method does not affect the central nervous system.
Another field of application of conduction anesthesia is dentistry. In the case of operations on the teeth, a local anesthetic of the responsible nerves in the region of the jaw is sufficient to completely numb the teeth and thus perform the treatment painlessly.
Which method of anesthesia is used is always a joint decision of anesthesiologists and patients.
For each type of anesthesia, an exact planning is first carried out. This includes, in particular, a conversation with the person affected, whether a previous line anesthesia was performed and whether it was well tolerated. Depending on the procedure, the position of the anesthetic and the appropriate local anesthetic are chosen.
For deeper nerve bundles, such as the arm plexus, the exact position can be searched with an ultrasound machine. The injection site is disinfected and the drug is drawn up in a syringe. The cannula is inserted into the skin and advanced to the appropriate location. There, it is then first checked whether the cannula is outside of blood vessels, since the local anesthetics should not enter the bloodstream. Thereafter, several depots of the local anesthetic are injected around the nerve.
Depending on the application, an electrical measurement can be used to determine if the anesthetic is successful or if more medication is needed. The cannula is withdrawn and it is waited a few minutes until the full effect occurs.
Anxious patients may be given a tranquilizer, such as midazolam, before the anesthesia, so they will not notice much of the anesthesia and the procedure.
The oldest local anesthetic is today only known as a drug cocaine. Although this is actually no longer used in medicine, the current local anesthetics act in the same way. Used are bubivacaine, lidocaine, ropivacaine, prilocaine, procaine and some other substances.
The different drugs differ in their effectiveness, their duration of action, the time to onset and their controllability.
In dentistry, lidocaine has proven its worth. Which means are used depends on the type and duration of the procedure and the individual tolerability.
When used correctly and without the local anesthetic getting into the bloodstream, the side effects are minor and much easier than with general anesthesia. Locally, incompatibilities and swelling are possible. In a known allergy another anesthesia method should be chosen because allergic reactions to allergic shock are possible.
If the local anesthetic gets into the blood and spreads throughout the body, the side effects increase depending on the concentration in the blood. First, dizziness, headache, drowsiness and nausea are possible. A higher dose may cause coma and respiratory paralysis.
The local anesthetics also have effects on the cardiovascular system. The blood pressure drops and the cardiac output decreases. It can also lead to a slowing of the heartbeat and a cardiac arrhythmia. In extreme cases, cardiovascular arrest may occur.
Because of these potential side effects on the cardiovascular system, serious cardiac bypass disorders and decompensated cardiac fatigue are contraindications for lead anesthesia. In this case, the person under general anesthesia can be better controlled.
The duration of a lead anesthesia depends on several factors. The different local anesthetics have different activity times. For short interventions, less than one hour, a single administration of the local anesthetic is sufficient. However, longer operations can be performed under a line anesthesia. For this purpose, the anesthetist has a catheter in the anesthetic area and can if necessary administer another dose of local anesthetic. Without further anesthesia, the lead anesthesia lasts only a few hours.
Oberst tube anesthesia is an anesthetic procedure for fingers and toes. The procedure is used in an emergency after injuries as well as during planned operations. Each finger or toe has a total of four major nerves, all of which must be anesthetized. Two nerves lie on the flexor side and two on the extensor side. In colonial anesthesia, all four nerves are anesthetized with only two punctures.
The cannula is inserted on the extensor side and advanced along the bone to the nerves of the flexor side. There, the first amount of local anesthetic is injected. After a slight withdrawal, another amount can be injected on the extensor side. The same thing is repeated on the other side of the finger or toe. After just a few minutes, the finger or toe is completely painless and surgery can be performed.
Since the responsible muscles are on the forearm or lower leg, the mobility is maintained throughout and only the touch and pain sensitivity is turned off. The name Colonel goes back to a German surgeon in the 19th and 20th centuries, who developed this stun technique.
For dental treatment, a lead anesthesia can be used to allow a painless procedure. The upper jaw is responsible for the superior alveolar nerve, which originates directly from the middle branch of a cranial nerve called the trigeminal nerve . Each tooth has its own branch off the main nerve and depending on where the anesthesia is set, only a few teeth and the outside gums become numb.
The cannula is usually inserted into the top of the gum and lidocaine is injected. Some dentists use a combination of the local anesthetic lidocaine and epinephrine, as this can prevent heavy bleeding.
The anesthesia will stop after a few minutes and last for about two hours. Before the anesthetic, the dentist asks if previous local anesthetics were well tolerated. A success check usually does not take place. If pain persists at the beginning of treatment, a second dose of local anesthetic is given. Since the effect lasts only briefly, the person concerned can leave the practice after the treatment and does not need further control.
For dental treatments on the lower jaw, the procedure is basically the same as on the upper jaw. After confirming that previous treatments have been well tolerated, the lower alveolar nerve is anesthetized. This comes from the nerve Mandibularis, so the lower jaw nerve, forth. This nerve branch is also part of the cranial nerve trigeminal nerve .
Unlike the upper jaw, however, a single syringe is enough to completely numb the lower half of the lower jaw. The nerve first passes through the lower jaw bone and leaves it in the area of the molars. At this point, the anesthesia can be set. A success check only takes place through the perception of pain at the beginning of the treatment.
Again, the anesthetic stops about two hours after the last injection. For longer procedures, a renewed dose of local anesthetic may be necessary. As long as the anesthetic works, the muscle power of the lip muscles is weakened. This causes food and drink during this time is not really possible, as the lower lip is hanging on the stunned side.
The ankle foot block anesthesia stuns all the nerves that feed the foot above the ankle. For this a total of five injections are necessary. After a thorough disinfection, approximately three to five milliliters of xylocain or ropivacaine are injected near each nerve.
Local side effects can be hematomas or nerve damage. Under a foot block, various operations can be performed on the foot and on the toes.
No foot block should be used for infections of the ankle or blood clotting disorders.
Basically, every medical procedure requires a duty to inform. The person concerned must be informed about the procedure, possible side effects and long-term consequences. An overview of alternative anesthetic procedures is also part of the Enlightenment. The affected person must also have the opportunity to ask questions. A reconnaissance sheet, as with a general anesthetic, with signature is not essential. An oral explanation is sufficient. Depending on the risk and type of intervention, the explanation takes place in different detail.