Difference Between an Epidural and a Spinal Block (With Table)

An epidural or spinal block is a form of anesthesia that involves injecting a local anesthetic near the spinal cord and nerve roots. It helps relieve in a specific area of the body, such as the stomach, hips, legs, or pelvis. The use of epidural and spinal anesthesia is most common in operations of the lower abdomen and legs. In labor, epidural anesthesia is often utilized. However, it can also be used to assist manage pain following major abdominal or chest surgery.

Epidural vs Spinal Block

The difference between epidural and spinal block or anesthesia is that the injection of medicine into the “epidural space” is what epidural analgesia is all about. It takes around 10-15 minutes for pain relief to start because the medicine must penetrate the membrane (dura mater) surrounding the spinal cord before reaching the targeted nerves. The use of a catheter during injecting allows for a continual introduction of pain medication throughout the labor or any surgeries as well as the addition of stronger drugs if needed. The injection of medicine into the fluid bathing the spinal cord (cerebrospinal fluid, or CSF) is known as spinal analgesia or anesthesia. The spinal needles are substantially finer than the epidural needles, and the spinal dosages are much less. However, since there is no catheter and hence no continuous infusion, the duration of pain alleviation is limited (approximately 1-2 hours).  

A tubular syringe and a tiny, flexible catheter are inserted into the area between the vertebral column and the outer layer of the spinal cord (epidural space) in the middle or lower back for epidural anesthesia. A local anesthetic is used to numb the region where the needle will be put. After the catheter has gone through, the needle is placed and withdrawn. The catheter is not removed. As needed, anesthetic drugs are given into the catheter to benumb the body above and below the injection site. The catheter remains attached to the back so that it may be reused if more medication is required.  

A similar technique is used for spinal anesthesia or spinal block. However, the anesthetic drug is delivered into the cerebrospinal fluid, which surrounds the spinal cord, using a much smaller needle. A local anesthetic is applied to the region where the needle will be put initially. The anesthesia is given when the needle is directed into the vertebral column. Without the use of a catheter, this is frequently done. The body below and occasionally above the injection site is numbed by a spinal anesthetic. Until the anesthesia wears off, the person might not be able to move his or her legs.

Comparison Table Between an Epidural and a Spinal Block

Parameters of ComparisonEpiduralSpinal Block
ProcedureTo access the epidural space, the anesthetist puts a syringe into the desensitized region of your lower back.A spinal block is administered by injecting a single dose of medication into the dural sac.
Pain reliefPlacing the epidural typically takes about 10 minutes. Giving it another 10–15 minutes one will be good pain relief.The patient will notice an instant reduction in discomfort.
Action retentionThe effect will last from 12 to 18 hoursThe effect will only last up to 2 hours.
SensationSpinal blocks are often used for brief, straightforward operations. The bottom half of the body loses sensation completely after the analgesic has done its work.Epidurals are more commonly utilized during labor since their effects might persist as long as the labor persists. The patient can sense sensations without discomfort thanks to efficient epidural anesthesia.
Side effectsSide effects such as cardiac rhythm difficulties or convulsions caused by the catheter tip piercing a vein may happen. Headache with Hematoma in the Epidural Space.The most common side effects of Spinal block are headache, low blood pressure, and back pain.

What is an Epidural?

A tubular syringe and a tiny, flexible catheter are inserted into the area between the vertebral column and the outer layer of the spinal cord (epidural space) in the middle or lower back for epidural anesthesia. A local anesthetic is used to numb the region where the needle will be put. 

It’s a sort of anesthetic that doctors use to sedate patients’ spinal nerves and stop pain messages from reaching their brains during surgery. Within 10 to 20 minutes, it normally starts working. They’d have a nerve block using a catheter, which is a thin, flexible tube that runs along their spine in the small of their back and continuously distributes drugs to keep them pain-free during surgery. The nerves that convey pain impulses are targeted with an epidural. As a result, they will still be able to sense pressure and touch. 

Even if you don’t have any discomfort in your lower body, you might be able to move around with a little assistance. When a woman decides to have an anesthetic during delivery, physicians often prescribe an epidural nerve block for these reasons. Blood pressure drops, urination problems, and a hangover is some of the side effects. Epidural hemorrhage, nerve injury, and infection are all rare consequences.   

What is a Spinal Block?

Friedrich Gaedcke was the first person to chemically extract cocaine, the coca plant’s most powerful alkaloid, in 1855.

“Erythroxyline” was Gaedcke’s name for the chemical. Karl Koller, an Austrian ophthalmologist, injected a 2% solution of cocaine into his eye in 1884 and used needles to evaluate its efficiency as a regional anesthetic. A few weeks later, at the Heidelberg Ophthalmological Society’s annual meeting, he reported his findings. The first brachial plexus block was done by William Halsted the following year.  

Most procedures below the waistline can be done using a spinal anesthetic. An anesthetist administers spinal anesthesia. A very small needle is put into the center of the lower back, and local anesthesia is delivered into the fluid around the spinal column through the needle.

The nerves that feed the belly, hips, bottom, and legs are numbed by regional anesthesia. One won’t feel any pain after the procedure and won’t be able to move your legs until the nerves are fully paralyzed. Other drugs that can be administered give good pain relief for several hours after the procedure are also available.

When surgery is performed on the lower extremities, perineum (e.g., surgery on the genitals or anus), or lower body wall, subarachnoid (spinal) block provides a secure and reliable alternative to general anesthesia (e.g., inguinal herniorrhaphy).  

Main Differences Between an Epidural and a Spinal Block

  1. The anesthesiologist inserts a syringe into the desensitized region of your lower back to get accessibility to the epidural space, whereas a single dosage of medicine is injected into the dural sac to give a spinal block.  
  2. Epidural insertion pain takes more time to subside. It can be as much as 10 minutes. One’ll be pain-free in 10–15 minutes. The patient will feel less uncomfortable right away.  
  3. For Epidural block, the effect will continue to last from 12 to 18 hours, whereas for a spinal block, the effect lasts for up to 2 hours.  
  4. For simple, quick surgeries, spinal blocks are frequently employed. After the analgesic has taken effect, the lower half of the body loses feeling. Epidurals are used more frequently during labor because their actions might last as long as the labor does. Due to effective epidural anesthesia, the patient can feel sensations without pain.  
  5. As a result of the catheter tip penetrating a vein in case of an epidural block, side symptoms such as heart rhythm problems or spasms might occur. Hematoma in the Epidural Space is causing a headache. Back discomfort, headache, and low blood pressure are the most prevalent negative effects of spinal block. 


Regional anesthetic methods for surgery, obstetrics, and postoperative pain control have become increasingly popular in recent years. A subarachnoid injection is followed by the installation of an epidural catheter and the injection of epidural drugs in the combined spinal-epidural (CSE) procedure, which is a relatively novel anesthetic option. The early onset of spinal medicines and subsequent administration of pharmaceuticals for extended anesthesia allows for immediate pain alleviation or induction of regional anesthesia.

Additionally, postoperative anesthesia can be administered for long periods via the epidural catheter. Clinical investigations have shown that the CSE approach delivers optimal surgical circumstances in the same amount of time as a single-shot subarachnoid block and with advantages over a traditional epidural block. CSE anesthesia has the benefit of enabling both spinal and epidural anesthesia.


  1. https://europepmc.org/article/med/8198262
  2. https://rapm.bmj.com/content/25/6/591.abstract
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