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What is an epidural?
An epidural is a type of regional anaesthetic which effects a large area of your body. Painkilling drugs are passed into the small of your back, via a fine tube, to the nerves in your body that carry pain signals during labour. This results in a numbness in the body from the waist down, providing very effective pain relief for vaginal delivery, or allowing you to stay awake and alert during birth by caesarean section.
How is an epidural administered?
Your anaesthetist will inject local anaesthetic into the lining of the spinal cord through your lower back. Guiding a hollow needle between the small bones in your spine, the needle enters the space between the layers of tissue in your spinal column (the epidural space). A fine tube, or catheter, is then passed through the needle. Once the tube is in place, the needle is removed. The tube is taped up your back and over your shoulder.
Keep very still while your anaesthetist sets up the epidural. You will either be on your side or sitting on the edge of the bed. You will be instructed to curl forward to open up the spaces between the bones of your spine. Concentrate on your breathing to help you to keep still; breathing in deeply through the nose and out slowly through the mouth. It may help to hold hands with your birth partner and keep eye contact with them.
Epidural painkillers are administered in several ways:
- Injection with top-ups: Your anaesthetist injects a mixture of painkillers into the tube to numb the lower part of your stomach. If the epidural is working well, you should no longer be able to feel your contractions. As the epidural begins to wear off, you can have top-ups which last between one and two hours.
- Continuous infusion: Your anaesthetist will set up an epidural catheter. The other end of the tube is attached to a pump, which feeds the pain-relieving epidural solution into your back continuously. You can have stronger top-up doses of local anaesthetic as well, if you need them. Sometimes the pump is under your control. This is called patient-controlled epidural analgesia or PCEA, but is usually only available in larger teaching hospitals.
- Combined spinal epidural (CSE): You'll be injected with a mini spinal: a low dose of pain-relieving drugs, which works quicker than an epidural alone. At the same time, the anaesthetist inserts a catheter without passing any drugs down the tube. When the effect of the mini-spinal injection starts to wear off, your anaesthetist will pass the epidural solution through the tube to give you ongoing pain relief.
How does it work?
An epidural works the same way as a local anaesthetic, to numb the nerves that are carrying pain signals from your uterus (womb) and cervix to your brain.
In Australia, most hospitals use low-dose epidurals. These contain a mixture of painkilling drugs, usually a local anaesthetic, bupivacaine, and an opioid, fentanyl. The advantage of a low-dose epidural is that you may have some sensation in your legs and feet, which is why some people call it a mobile epidural. However, the low-dose epidurals which most hospitals offer are not the same as an ambulatory or walking epidural, which can only be provided if there are ample staff to provide the extra monitoring you'll need. When should I have it?
An epidural can be administered at any point in labour, however most women choose to have an epidural when their contractions are getting quite intense, which is often when their cervix has dilated by about 5cm or 6cm.
You'll also be offered an epidural if your labour is being sped up with a Syntocinon drip. This is a synthetic version of the hormone oxytocin, which makes your cervix dilate and contractions intensify. You may need extra pain relief, because this can make your contractions difficult to cope with.
Once your epidural is in place, it should stay in until after your baby is born and your placenta delivered. It can also provide pain relief after your baby is born if you need stitches.
What are the advantages of having an epidural?
- It usually provides excellent pain relief during labour.
- It works fairly quickly, taking about 20 minutes to insert and set up and another 20 minutes once the anaesthetic has been injected before starting to work.
- Top-ups can be given by an experienced midwife , so you don't usually need to wait for an anaesthetist once the epidural is in place.
- Your mind remains clear. You may still be aware of your contractions, but feel no pain.
- If you have high blood pressure, it has a useful side-effect of lowering blood pressure.
- It can be topped up with stronger local anaesthetic if you need a caesarean section.
What are the disadvantages of having an epidural?
- It may not work properly at first, and you may find that you are numb in only parts of your tummy. If you're not pain-free within half an hour of the epidural starting the procedure may need to be repeated.
- Immediately after the epidural has been inserted, some women experience a drop in blood pressure that can cause nausea and dizziness.
- Some women experience pain at the injection site.
- Because of muscle weakness in the legs, women with an epidural anaesthetic may be confined to bed until the drug wears off.
- In most cases, due to the lack of sensation in the lower body, a urinary catheter must be inserted.
- Having an epidural may make the second stage of labour, the pushing stage, last longer. If you don't feel an urge to push and there is no sign of your baby's head yet, you should be encouraged to wait for at least an hour or until you feel the urge to push.
- You're more likely to need your labour speeded up with a Syntocinon drip. However, hospital staff should give you the chance to have a longer, slower labour, before using drugs to speed it up.
- There's more chance of your baby needing to be born with the aid of forceps or ventouse and this may be because epidurals can make it difficult for your baby to move into the best position to be born. By the time you’re ready to give birth your baby is more likely to end up in a posterior position, with the back of its head towards your spine, even if baby wasn't in that position when labour started.
- There is a small risk of you having a severe headache (around 1%). This can happen if the epidural needle punctures the bag of fluid which surrounds the spinal cord, causing a leak of fluid . It's usually treated by taking a small amount of blood from your arm, and injecting it into your back to seal the hole made by the needle. This is done after your baby is born, and may need to be done more than once to achieve a seal.
- Around one in 550 women experience ongoing patches of numbness near the injection site.
- There's a very small risk of nerve damage, leaving you with a numb patch on your leg or foot, or a weak leg. This rarely happens. The risk is about one in 1,000 for temporary nerve damage and one in 13,000 for permanent damage.
- It may make you feel shivery.
- You may develop itching or a fever.
- You may need a catheter to empty your bladder.
- You will need more monitoring. Your baby's heartbeat will be monitored continuously for at least 30 minutes when you're first given an epidural, and after each top-up. Your blood pressure is taken every five minutes when the epidural is started, for about 30 minutes, and after each top-up.
What are the possible effects of an epidural on my baby?
- An epidural make cause your blood pressure to drop, which can affect the flow of oxygen to your baby. You'll need to have a small tube, called an intravenous cannula, inserted into your hand or arm in case your blood pressure drops suddenly. Low blood pressure can be treated by fluids fed through the cannula to increase your blood volume.
- Epidural solutions contain the opioid, fentanyl, or a similar drug, which can cross the placenta. In larger doses (more than 100 micrograms), these drugs may affect baby's breathing, or cause drowsiness.
Tips for epidurals:
- Not everyone can have an epidural. Talk to your doctor if you think you have a medical condition that might affect whether you can have one.
- Epidurals are only available in obstetrician-led maternity units, not in birth centres, midwife-led units or for home births.
Depending on what your local unit offers and when you go into labour, be prepared for the possibility that you may not be able to have one. Even maternity units equipped to give epidurals may not offer a 24-hour service.