Local Anesthesia is a process in which a drug or a group of drugs are used to attain loss of sensation without loss of consciousness. Local Anesthesia is widely used for minor surgeries and in dentistry.
Local Anesthesia definition by Stanley F. Malamed
Local anesthesia has been defined as loss of sensation in a circumscribed area of the body caused by depression of excitation in nerve endings or inhibition of the conduction process in peripheral nerves.
Desirable properties of Local Anaesthetic
- It should not be irritating to the tissue.
- It should not cause any permanent alteration of the nerve structure.
- It should have low systemic toxicity.
- It must be effective both in injecting & topical form.
- The time of onset of anesthesia should be as short as possible.
- The duration of action must be long enough to permit completion of the procedure yet not so long as to require an extended recovery.
These were some of the desirable properties of Local Anaesthetic.
How can one attain Local Anesthesia?
- Mechanical trauma (compressed tissue)
- Low temperature
- Anoxia (absence of oxygen)
- Chemical irritants
- Neurolytic agents such as alcohol and phenol
- Chemical agents such as local anesthetics
What is a local anaesthetic?
A drug used for attaining local Anesthesia is known as a local anaesthetic.
Types of Local Anaesthetic
Local anaesthetic are of two types:
- Para-Aminobenzoic Acid (PABA) based known as Esters
- Non-Para-Aminobenzoic Acid (PABA) based known as Amides
Ester Local Anaesthetics:
Amide Local Anaesthetics:
- Lignocaine (also known as Lidocaine)
Side-effects of Local Anesthesia
Local Anaesthetics have some effects over the area of operation like tingling sensation, numbness, heavy feeling, swelling. These are some of the normal effects of local anaesthetics but there are also some side effects of local anaesthetics listed below:
- Muscle twitching
- Metallic taste
If the patient goes unconscious or syncope then it needs immediate medical attention.