Exploring the Sciatic Nerve Block

Introduction:

Pain in the lower back and legs are frequent and can be due to nerve pain. The femoral and sciatic nerves are the two primary nerves supplying the thighs, legs, and feet. The branches of these two are distributed over the legs to the foot. Sometimes, the patient is delivered a sciatic nerve block to overcome the leg pain. When the anesthesia is deposited near the sciatic nerve, it is called a sciatic nerve block. After its deposit, the sciatic nerve and its branches get numb, relieving the sciatic nerve's pain. This topic briefs about the uses, risks, and benefits of the sciatic nerve block.

What Is a Sciatic Nerve?

The sciatic nerve is one of the longest and widest nerves in the human body. It originated from the lower spine area. It runs through the hips, buttocks through the thigh, ending just below the knee, giving two more branches, the tibial and common fibular nerve. It is present in pairs, one from each side of the buttocks down to the legs. The primary role of the sciatic nerve is to provide sensory (to sense the area) and motor (to provide movement in the area) supply to the skin and muscles of the thigh, leg, and foot. The sciatic nerve provides functions of motor and sensory nerves. The purposes of sciatic nerves are:

• It helps the legs and feet move.

• It helps feel or sense movement in the legs.

What Is a Sciatic Nerve Block?

Sciatic nerve block blocks the pain caused by the sciatic nerve and its branches. It is performed by injecting anesthesia into the sciatic nerve, which blocks the pain signals sent by the sciatic nerve to the brain. Any damage to the sciatic nerve or sciatica is the main reason for administering a block in the sciatic nerve.

When Is a Sciatic Nerve Block Used?

A sciatic nerve block is used in:

• Sciatica is nerve pain from an injury or irritation to the sciatic nerve, originating in the buttocks. It usually occurs due to slipped disc problems. It has symptoms like weakness in the legs, burning sensation, shooting pain, and back leg pain.

• Degenerative disc diseases (loss of disc cushioning due to aging) require a sciatic nerve block.

• Herniated discs (problems related to disk displacement) are painful.

• Compression fractures.

• Osteoporosis (bone becoming brittle).

• Spinal stenosis (spinal canal narrowing) puts pressure on the spine and causes pain.

• Spinal tumors (tumors present in the spinal area or spinal cord, meaning their origin in the spinal cord).

• A sciatic nerve block is administered in knee, calf, ankle, or foot surgery.

How to Administer a Sciatic Nerve Block?

The steps to perform a sciatic nerve block are as follows:

• The patient is made relaxed.

• Depending upon the injection site, the patient lies on the belly or sideways.

• The area on the buttocks is cleaned with an antiseptic solution.

• Local anesthesia is used to numb the area before injecting the nerve.

• The doctor palpates the area with their fingers.

• The doctor presses firmly over the buttocks to decrease the distance between the skin and the needle.

• A nerve stimulator and X-ray guidance are used to locate the sciatic nerve.

• The anesthesia is then administered to the sciatic nerve.

• The site of needle insertion is pressed and the bandage is done.

What Happens After the Procedure?

Soon after the procedure, the anesthesia starts its work, and the patient's pain is relieved for several days to weeks, sometimes months. But as soon as the anesthesia wears off its effect, the patient starts experiencing pain again. The patient is relieved for the long term by injecting steroids and anesthesia. These steroids start their work within weeks and can last for a month. The patient can return to everyday activities after 24 hours of injection. A full day's rest is enough to go with a sciatic nerve block injection for pain relief. The patient should avoid driving for 24 hours due to sedatives in the injection given.

When Is Sciatic Nerve Block Contraindicated?

In some conditions, the sciatic nerve block cannot be used:

• If any local infection is present on the needle's insertion site.

• Bed sores on buttocks.

• Blood clots or coagulopathy.

• Any previous nervous system disorders.

• Any allergy to local anesthetics.

What Are the Risks and Benefits of Sciatic Nerve Block?

Risks related to the sciatic nerve block are:

• Bleeding.

• Infection.

• Local anesthesia toxicity.

• Soreness at the injection site.

• Nerve injury.

• Nausea and vomiting.

The benefits of the sciatic nerve block are:

• Postoperative analgesia in surgical procedures.

• Used in knee, ankle, or leg surgeries.

• Used along with the femoral nerve block for better results in some surgeries.

• It relieves chronic pain in the legs.

What Is the Anesthesia Used in the Sciatic Nerve Block?

Local anesthesia is used in the sciatic nerve block to numb the nerve and eliminate the nerve pain signals going to the brain. As soon as the anesthesia is delivered, it starts working and immediately vanishes the pain, but its effect is short-term. For long-term results, steroids are given, which start their work slowly, taking nearly a week, and can work for about a month.

A sciatic nerve block is considered safe and effective in many cases of chronic leg pains. However, a few risks related to sciatic nerve block do express, like soreness or nausea. But they are helpful in cases of severe leg pain like sciatica.

Conclusion:

The sciatic nerve is one of the primary nerves of the legs. Chronic leg pains can be relieved by blocking the sciatic nerve's sensation. The sciatic nerve block relieves chronic nerve pain in the legs and lower back. Cases of sciatica, spinal stenosis, and disk displacement in the backbone are common problems requiring sciatic nerve block. Sciatic nerve block uses local anesthesia to block the nerve sensation around the sciatica nerve and its branches. It is an effective and safe way to relieve nerve pain. Conditions in which sciatic nerve block cannot use are infection and bed sores on the injection site.