What Is Local Anesthesia?

Local anesthesia is the method that temporarily removes the sensation of pain in one specific area of the body.

The patient does not lose consciousness.

They are aware of what is happening, can speak, and can communicate throughout the procedure.

When people hear the word anesthesia, they usually think of general anesthesia. Yet the most common anesthetic any of us encounters in a lifetime is almost certainly local anesthesia.

From dental treatment to skin biopsies, from minor surgery to some cosmetic procedures, a great many interventions are performed under local anesthesia.

How does local anesthesia work?

The nerves in our body carry information from the tissues to the brain as electrical signals. Pain is one of those signals.

Local anesthetic drugs temporarily prevent the nerves from generating that electrical conduction.

As a result, no pain signal reaches the brain from the treated area.

The patient may still feel touch or pressure, but not pain.

Once the drug wears off, nerve function returns to normal.

Do you stay conscious?

Yes. That is the defining feature of local anesthesia.

The patient is awake throughout, can answer questions and can communicate.

In some patients, sedation may be added to reduce anxiety during the procedure. The patient then feels more comfortable, but the underlying logic of local anesthesia does not change.

Where is it used?

Local anesthesia is preferred particularly for small, limited procedures. For example:

• Tooth extractions and dental treatment
• Skin biopsies
• Removal of moles and cysts
• Minor plastic surgery procedures
• Nail surgery
• Some eye procedures
• Minor orthopedic procedures

In these procedures effective pain control can be achieved without the need for general anesthesia.

Are local anesthesia and sedation the same thing?

No. These two are often confused.

Local anesthesia is the temporary blocking of the nerves that generate pain.

Sedation is the administration of drugs that help the patient relax and reduce anxiety.

A patient may receive local anesthesia alone. In some cases sedation accompanies it, so that the patient feels no pain and also has a more comfortable experience.

Is pain felt under local anesthesia?

The purpose of local anesthesia is to remove pain.

At the start, however, there may be a short burning or stinging sensation while the drug is injected.

Once the drug takes effect, pain in the treated area largely disappears. The patient usually notices only touch, traction or pressure.

Are local anesthetic drugs safe?

The local anesthetics used in modern medicine are extremely safe.

But as with any drug, certain risks exist. The amount given, the site of application and the patient's characteristics are therefore assessed carefully.

At high doses in particular, or if accidentally injected into a vessel, some local anesthetics can:

• Affect heart rhythm
• Cause changes in blood pressure
• Produce neurological symptoms

So local anesthesia is also a procedure that requires medical knowledge and experience.

Why local anesthesia is not always trivial

There is a common perception that local anesthesia carries no risk at all, mostly because it is used in small procedures.

In reality local anesthetics are powerful pharmacological agents. Like many drugs used in anesthesia practice, they have defined dose limits and rules of application.

The spread of ultrasound-guided nerve blocks has made local anesthetics far more precise and safer to administer. That does not remove the need for careful use.

What is felt afterwards?

Numbness can continue for a while after the procedure. How long depends on the drug used: some act for one to two hours, others for considerably longer.

As the numbness wears off, the following may be noticed:

• Tingling
• A mild prickling sensation
• Sensation returning gradually

These are expected and temporary.

Are local and regional anesthesia the same?

Technically, regional anesthesia is also performed using local anesthetic drugs. The difference is where they are applied.

In local anesthesia the drug is given directly to the small area being treated.

In regional anesthesia the nerves that carry sensation from that area are targeted instead.

For shoulder surgery, for example, rather than injecting the shoulder itself, the nerves supplying it may be blocked.

This is why nerve blocks and regional anesthesia are covered under a separate heading.

Where local anesthesia sits in modern medicine

Today local anesthesia is not only a method for small procedures. As anesthesiology has developed, local anesthetic drugs have found much wider use in:

• Pain management
• Nerve blocks
• Regional anesthesia
• Postoperative pain control

Local anesthesia is therefore regarded as one of the building blocks of modern anesthesia.