Spinal anesthesia (or spinal anesthesia), also called spinal block, subarachnoid block, intradural block and intrathecal block, is a form of neuraxial regional anesthesia involving the injection of a local anesthetic or opioid into the subarachnoid space, generally through a fine needle, usually 9 cm (3.5 in) long A spinal technique uses a single injection.  With an epidural, a catheter is usually placed into the epidural space which allows multiple injections and/or an infusion of medication to be given.

A spinal anesthetic is the anesthetic technique used most frequently for patients having cesarean sections (assuming they don’t already have an epidural catheter in place).  A spinal anesthetic is also sometimes given when an epidural catheter is being placed.  This is called a combined spinal-epidural technique.

For an epidural:

• The doctor injects medicine just outside of the sac of fluid around your spinal cord. This is called the epidural space.
• The medicine numbs, or blocks feeling in a certain part of your body so that you either feel less pain or no pain at all depending on the procedure. The medicine begins to take effect in about 10 to 20 minutes. It works well for longer procedures. Women often have an epidural during childbirth.
• A small tube (catheter) is often left in place. You can receive more medicine through the catheter to help control your pain during or after your procedure.

For a spinal:

• The doctor injects medicine into the fluid around your spinal cord. This is usually done only once, so you will not need to have a catheter placed.
• The medicine begins to take effect right away.

Your pulse, blood pressure and oxygen level in your blood are checked during the procedure. After the procedure, you will have a bandage where the needle was inserted.

Spinal and epidural anesthesia work well for certain procedures and do not require placing a breathing tube into the windpipe (trachea). People usually recover their senses much faster. Sometimes, they have to wait for the anesthetic to wear off so they can walk or urinate.

Spinal anesthesia is often used for genital, urinary tract, or lower body procedures.

Epidural anesthesia is often used during labor and delivery, and surgery in the pelvis and legs.

Epidural and spinal anesthesia are often used when:

• The procedure or labor is too painful without any pain medicine.
• The procedure is in the belly, legs, or feet.
• Your body can remain in a comfortable position during your procedure.