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Jai Ganesh

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Local Anaesthesia

Local Anaesthesia

Gist

Local anaesthesia involves numbing an area of the body using a type of medicine called a local anaesthetic. These medicines can be used to treat painful conditions, prevent pain during a procedure or operation, or relieve pain after surgery.

Summary

Local anaesthesia involves numbing an area of the body using a type of medicine called a local anaesthetic.

These medicines can be used to treat painful conditions, prevent pain during a procedure or operation, or relieve pain after surgery.

Unlike general anaesthetics, local anaesthetics don't cause you to lose consciousness.

This means they're generally safer, don't normally require any special preparation before they're used, and you can recover from them more quickly.

How local anaesthetics work

Local anaesthetics stop the nerves in a part of your body sending signals to your brain.

You won't be able to feel any pain after having a local anaesthetic, although you may still feel some pressure or movement.

It normally only takes a few minutes to lose feeling in the area where a local anaesthetic is given.

Full sensation should return when the medicine has worn off a few hours later.

How local anaesthetics are used

Local anaesthetics are usually given by dentists, surgeons, anaesthetists, GPs and other doctors.

Some medicines containing mild local anaesthetic are also available on prescription or over the counter from pharmacies.

Depending on what they're being used for, local anaesthetics can be given as injections, creams, gels, sprays or ointments.

Treating pain

Slightly painful conditions, such as mouth ulcers and sore throats, can sometimes be treated with over-the-counter gels and sprays that contain a local anaesthetic.

Injections of a local anaesthetic and steroid medicine may be used to treat more severe conditions, such as long-term joint pain.

Preventing pain during and after surgery

A local anaesthetic, usually given by injection, may be used along with a sedative medicine to keep you relaxed while an operation or procedure is carried out.

Local anaesthetics are mainly used for relatively minor procedures, such as:

* a filling or wisdom tooth removal
* a minor skin operation, such as the removal of moles, warts and verrucas
* some types of eye surgery, such as cataract removal
* a biopsy (where a sample of tissue is removed for closer examination under a microscope)

A local anaesthetic may occasionally be used for more major surgery when it's important for you to be awake, such as during certain types of brain surgery, or to prevent pain after a major operation that's been carried out under a general anaesthetic.

Details

Local anesthesia numbs a part of your body so that your doctor can stitch up a wound or take a biopsy without you feeling any pain. Unlike general anesthesia, where you are put to sleep during a procedure, you will be conscious during the procedure.

You can also use local anesthesia for relief from pain caused by cancer and some bone and joint diseases. Local anesthesia drugs help and are safer than opioids.

How Does Local Anesthesia Work?

Your nerves carry pain signals to your brain. Local anesthetic drugs block your nerves and prevent them from carrying these signals. This nerve blockage saves you from feeling pain.

This blockage is temporary. Your nerves will start working in a while. Both movement and feeling will return.

How Do Local and General Anesthesia Differ?

Doctors will need you to take general anesthesia for long and extensive procedures. You breathe gas through a mask or get an injection and fall asleep. When you wake up, the surgery is over.

General anesthesia needs expert care. Since you're unconscious, your heartbeat, respiration, oxygenation, and blood pressure must be watched carefully. You may need help in breathing, too.

While you're unconscious, you may vomit and drag the vomited material into your lungs. This can cause aspiration pneumonia, a dangerous condition. For your safety, your doctor will want you to fast for a few hours before anesthesia.

General anesthesia is given to you by an anesthesiologist after your doctor assesses your health in advance.

Local anesthesia, on the other hand, is simpler. Since you're awake — with only part of your body numbed — it's safer. Side effects like nausea and vomiting are not as common as those after general anesthesia.

What Are the Advantages of Local Anesthesia?

Local anesthesia relieves pain without the risks and preparation of general anesthesia. You're conscious and alert, and only part of your body is numb. It has other benefits too:

* An anesthesiologist is not needed. Your family doctor or surgeon gives the local anesthesia before starting the procedure.
* Local anesthesia side effects are uncommon and usually mild.
* Dangers like aspiration pneumonia are rare. Your procedure won't be delayed because you've eaten recently.
* You can go home sooner.
* Costs are much lower.

What Are Types of Local Anesthesia?

Local anesthetic drugs are used in three different ways:

* Local application. You can apply local anesthetic ointment to open sores or mouth ulcers. Anesthetic eye drops numb the eye for your doctor to remove eyelashes or particles.

* Local injection. Your doctor injects a local anesthetic drug under the skin or deeper. You won't feel the needle pricks as your doctor sews a wound. Your doctor also uses such injections to take a biopsy or do a spinal tap to get cerebrospinal fluid (CSF) for testing.

* Nerve blocks. Local anesthetic drugs are injected near nerves to block the pain from the area supplied by the nerve.

Your doctor uses nerve blocks for dental treatment and eye operations. Spinal anesthesia, used for doing cesarean section, is also a type of nerve block.

Two kinds of local anesthetic drugs are used nowadays. The commonly used drugs are amides like lignocaine, prilocaine, and bupivacaine. The other group is esters like cocaine, procaine, and amethocaine.

How Long Does Local Anesthesia Last?

Most often, the effects of local anesthesia wear off quickly. The effect of commonly used local anesthetic drugs, like lignocaine, wears off in about an hour. Your doctor may combine a local anesthetic with other drugs like steroids, clonidine, or epinephrine (adrenaline). This prolongs the anesthesia.

It's important to take care of the numbed part carefully. After dental treatment, for example, your mouth will be numb, and you might burn yourself by drinking hot coffee.

When the local anesthesia is needed to work longer, your doctor will use slow-release forms of the drugs or apply continuous infusion of the local anesthetic drugs.

Additional Information

Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, i.e. local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with reduced pain and distress. In many situations, such as cesarean section, it is safer and therefore superior to general anesthesia.

The following terms are often used interchangeably:

* Local anesthesia, in a strict sense, is anesthesia of a small part of the body such as a tooth or an area of skin.
* Regional anesthesia is aimed at anesthetizing a larger part of the body such as a leg or arm.
* Conduction anesthesia encompasses a great variety of local and regional anesthetic techniques.

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