Fluoroscopy Guided Epidural Anesthesia

Introduction

Epidural anesthesia is a type of local anesthesia, meaning a small, limited area of the body is injected with an anesthetic drug. That small area has a loss of sensation and does not feel pain during a procedure. The advantage of local anesthesia is that the patient is awake during the procedure.

What Is Epidural Anesthesia?

Epidural anesthesia is the technique of administering an anesthetic agent into the space surrounding the spinal cord and spinal nerves. The epidural space is filled with fluid. This anesthesia provides pain relief and numbness to the region of the body from below the belly button to the upper part of the legs. This happens due to the blocking of signals transmitted from the spinal cord to the brain. Pain is managed, and there is a total loss of sensation temporarily. It is known by other names like epidural block, epidural steroid injection (ESI- in which a steroid is injected in place of an anesthetic agent to relieve chronic pain), and neuraxial anesthesia.

What Are the Indications and Contraindications of Epidural Anesthesia?

An epidural block is mainly used in surgeries involving the lower half of the body:

• During labor and childbirth.
• As an alternative to general anesthesia.
• For back pain.
• For chronic pain.
• For postoperative pain relief.

Surgeries performed on the lower legs, pelvis, lower abdomen, and perineum like:

• Hip and knee surgery.
• Vascular reconstruction of lower legs.
• Amputation.
• Rib and sternum fractures.
• Thoracic surgery.

But some conditions are unfavorable for epidural anesthesia like:

Absolute Contraindications:

• Patient refusal.
• Infection at the site of injection.
• Anticoagulant therapy.
• Increased intracranial pressure.
• Systemic infection.
• Hypovolemic shock.
• Allergy to an anesthetic agent.

Relative Contraindications:

• Uncooperative patients.
• Deformity of the spine.
• Aortic stenosis.
• Pulmonary hypertension.
• Neurological disorder.

What Is Fluoroscopy?

Fluoroscopy is an imaging technique that uses a continuous beam of X-rays directed at the body area to produce live images of the structures in motion. The X-ray images are displayed on a computer monitor like an X-ray movie. The movement of the body part or any instrument can be visualized clearly. An X-ray contrast dye can also be used in fluoroscopy. Fluoroscopy is used in many procedures and examinations for diagnosis or treatment.

The various indications of fluoroscopy are as follows:

• Catheter placement and manipulation to guide its movement in blood vessels, urinary tract, or bile ducts.
• Stent placement to open or widen the blocked or narrowed blood vessels, respectively.
• Angiograms to view the organs, arteries, and veins.
• Barium X-rays to detect the abnormalities of the digestive tract and enemas for cleaning and bowel emptying.
• Orthopedic surgery to direct joint replacements and fracture corrections.

But fluoroscopy has its few health hazards, which are:

• Exposure to ionizing radiations used in this device can cause injuries to the skin being irradiated and underlying tissue. They occur within a few days after exposure and are called radiation burns.
• Radiations can also lead to cancer of the skin and other body parts, which develop years after exposure.

What Is Fluoroscopy-Guided Epidural Anesthesia?

Fluoroscopy-guided epidural anesthesia is the technique of administering an anesthetic drug or steroid into the epidural space with the help of an image-guided approach that uses an X-ray beam. The conventional method of epidural anesthesia was non-image guided and lacked accuracy in the injection. But with the advanced technique of fluoroscopy, the moving structures can be clearly evaluated for abnormalities. But it has the risk of radiation exposure and is expensive.

What Are the Advantages of Fluoroscopy-Guided Epidural Anesthesia?

The Advantages of Using an Epidural During Delivery Are:

• Epidural anesthesia is very effective in pain management during childbirth and labor.

• They are a relatively safer method of anesthesia.

• The patient has the ability to move and push when required.

• During prolonged labor, anesthesia can sedate the patient to take rest and recover.

• It can be used for cesarean (C-section) delivery as well.

• Epidural can be given at any point of time during labor.

The Advantages of Using Epidural Anesthesia During Surgery Include the Following:

• It shows real-time images for accurate injection of anesthetics or steroids.

• The patient will have minimal chances of nausea and vomiting.

• The patient will heal and recover soon with this anesthesia than with general anesthesia.

The Advantages of Epidural Steroid Injections Include the Following:

• The patient will be relieved temporarily or permanently from chronic pain.

• The quality of life will improve with the ability to easily perform all daily activities.

• It will help to locate the source of pain when the patient has multiple sites of origin of pain.

• It is a non-invasive procedure for controlling pain and will eliminate the need for other invasive procedures for pain relief.

What Is the Technique of Fluoroscopy-Guided Epidural Anesthesia?

• Prior to the procedure, an IV (intravenous) cannula is inserted into a vein to ensure quick access to inject drugs in case of emergency during epidural anesthesia (for example, if blood pressure drops).

• The patient's position will be either lying on the side or sitting up with an arched back and chin tucked into the chest to have clear access to the site of needle insertion.

• The area is sterilized using an alcohol swab or betadine solution.

• Local anesthesia is given at the site to minimize pain during the epidural since the needle used will be larger than the normal needle.

• Then the epidural needle is inserted into the epidural space. The location of the needle depends on the surgery performed and the vertebra (thoracic, lumbar) to be accessed. The epidural needles used are Tuohy, Weiss, Crawford, and Hustead.

• The anesthetic agent is deposited at the site of insertion. Lidocaine, tetracaine, and bupivacaine are commonly used anesthetic drugs.

• Then a continuous X-ray beam is directed towards the site, which produces real-time fluoroscopic images to guide the needle during insertion or a catheter or stent during its placement.

• The patient will be asked to move to enhance the spread of anesthesia and to view the body part in movement through the images on the screen.

• If an epidural steroid injection is given, patients will lie on their stomachs or on their sides. The epidural needle is placed at the target area, and a contrast dye is injected to view the inflamed spinal nerves. Then anti-inflammatory drugs such as steroids or painkillers are injected.

• The needle is then withdrawn, and the area is cleaned and given a dressing.

What Are the Complications of Epidural Anesthesia?

• Severe headache.

• Secondary infections like osteomyelitis, epidural abscess, and meningitis.

• Nerve damage.

• Hematoma (blood clot).

• Bradycardia.

• Convulsions (seizure).

Conclusion

Epidural anesthesia without image guidance was practiced conventionally, but now fluoroscopy is used as an effective method to deliver the medication accurately. But it has to be used with caution because of radiation hazards. It involves an anesthesiologist, a radiologist, a neurologist, and a gynecologist (when used during childbirth).