Spinal and Epidural Anaesthesia
INFORMATION LEAFLET
What is a spinal?
The aim of this procedure is to block pain sensation in the lower half of the body. Local anaesthetic drug is injected into the fluid inside your spine by inserting a needle through the middle of your lower back. This numbs the nerves from the waist down to the toes. You can still feel touch and deep pressure, but will not feel pain. A spinal anaesthetic usually lasts two to three hours and may be combined with other anaesthetic techniques such as sedation or general anaesthesia.
Is a spinal the same as an epidural?
No, they are slightly different even though both involve an injection into the lower back. A spinal anaesthetic is typically a one-time injection providing pain relief adequate to perform an operation. Epidural analgesia is commonly used for pain relief during childbirth or after major surgery to the chest, abdomen or legs. With an epidural, your anaesthesiologist usually leaves a small flexible catheter in your back to allow for top-up injections or a continuous infusion of local anaesthetic. This can provide pain control for an extended period.
Why do we use epidurals for childbirth?
An epidural block provides the most effective form of pain relief during normal childbirth. A big advantage is that medication given is not passed to the baby as with other methods. After the block has been given it takes about 20-30 minutes to start working. This procedure will block pain sensation. You can still feel touch, pressure and have some muscle function allowing you to push/bear down when necessary. Your legs will feel weak and you may need to stay in bed after the epidural has been given.
What effect will an epidural have on the labour process?
The 2nd stage of labour (pushing phase) may last approximately 15-20 minutes longer.
Your obstetrician might need to use special instruments to aid the delivery your baby.
Your chances of needing a Caesarean section is not higher than when you receive other forms of pain medication.
General benefits of a spinal or epidural anaesthesia
You breathe better with a reduced risk of chest infection after surgery.
In pregnant patients, medication given via this route is not transferred to the baby.
Pregnant patients get to be pain free, but awake and fully conscious to experience the birth of their baby.
Excellent pain relief immediately after surgery.
Reduced need for strong pain relieving drugs.
Earlier return to eating and drinking after surgery.
Reduced risk of confusion after the operation, especially in older/more susceptible patients.
How is a spinal or epidural block performed?
You will be positioned by your anaesthesiologist (either sitting up or lying on your side; you are curled up with your chin on your chest).
Before the block is performed, the skin is cleaned with an antiseptic solution that feels cold.
Local anaesthetic is injected to numb the area of skin on your back before the spinal/epidural needle is inserted. This might sting a little.
Your anaesthesiologist will then carefully insert a spinal/epidural needle and advance it into the space between your vertebrae (backbones). It is important to keep still during this time. Occasionally, you might feel a brief tingling sensation shooting down a leg (parasthesia) during the procedure.
With epidurals, the catheter may need to be repositioned or reinserted to ensure optimal efficacy.
What to expect when an operation is performed under spinal anaesthesia
After the spinal has been given, you will lie down, your legs will start to feel warm and tingling and then heavy. The block usually takes 5 to 10 minutes to reach full effect.
If an operation is performed, the adequacy of the block will be tested before surgery is commenced.
Pain sensation up to the umbilicus will be completely blocked BUT you can still feel touch and deep pressure sensations. Giving more local anaesthetic may stop your breathing. We therefore aim to block only pain up to the umbilicus.
Occasionally the spinal/epidural may go higher than the umbilicus and you may feel short of breath, dizzy, nauseous or faint. The anaesthesiologist will give you something to reverse these feelings.
After your operation
It takes one to four hours for sensation to return.
As sensation returns, you may experience some tingling in the skin as the spinal wears off. At this point, you may become aware of some pain from the operation site.
You can normally drink fluids and perhaps have a light meal within an hour of the operation.
Side Effects and Complications
Common complications (1 to 10% of cases)
Minimal treatment usually
Low blood pressure (This can make you feel faint or sick.)
Itching
Difficulty passing urine
Pain during the injection
Redness, swelling or bruising
Referred shoulder pain during the operation
Rare complications (Less than 0.1% of cases)
May require further treatment
Nerve damage(This is usually temporary. The limb may feel numb,weak or have pain.)
Failed block
Prolonged or dense block
Headache
Backache
Very rare complications (0.0005% to 0.01% of cases)
Often serious with long-term damage
Paralysis
Feeling short of breath
Seizures
Allergic reactions
Bleeding into the spinal space
Sepsis/ Infection
High block
Retained epidural catheter
Brain damage or Death (Less than 0.0004% of cases)
Due to any other complication getting more severe
Heart attacks
Emboli (clots)
Lack of oxygen
*To contextualise: Risk of suffering a very rare complication is comparable to risk of dying from a lightning strike (0.0007%)
Important points to remember
Spinal and epidural anaesthesia aims to block pain sensation. You can still feel touch and deep pressure.
If an adequate spinal anaesthetic cannot be achieved for your operation, you will need a general anaesthetic. Please always adhere to the prescribed fasting guidelines before your operation. (See General Anaesthetic Information Leaflet.)
You may be unsteady on your feet when the spinal/epidural first wears off. Please ask for help when you initially get out of bed.
Certain patients can get a severe headache after an epidural (1/100 patients) or spinal (1/500 patients). This is called a post dural puncture headache and occurs when the sac around the spinal cord is punctured. Please consult your anaesthesiologist or obstetrician for treatment options.
If you experience persistent pins and needles in your legs or lower body for more than 48 hours after discharge, please contact your anaesthesiologist.
In the very rare occasion you should experience new onset lower backache or high temperature in the first few days after the anaesthetic, please promptly contact your GP or nearest hospital and inform your anaesthesiologist.
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