Obstetric Anaesthesia
What is an Epidural?
In obstetrics, epidural anaesthesia is used to temporarily numb the nerves carrying pain sensation from the womb and birth canal. A special epidural needle is inserted into the lower part of the back; a small amount of local anaesthetic may be first injected into the skin of the area. This causes a little sting but it is often the only part that hurts. The tip of the epidural needle is advanced into the space which contains the nerves before they enter the spinal cord. With the epidural needle in place, fine plastic tubing can then be passed through the needle. The needle is withdrawn and the plastic tube taped in place so drug doses can be made through it with no further injections.
What happens first?
Before performing an epidural anaesthetic, first your anaesthetist will ask you about your previous anaesthetic history and will assess your medical and obstetric condition. You will be asked questions about any allergies you may have, and about any medication you may be taking. An intravenous drip will be started, usually through an injection on the back of your hand. Extra fluid is given through this drip. It is also used to give drugs rapidly when necessary. If you are in extreme pain when requesting your epidural, then your pre-anaesthesia consultation may be brief. You can rest assured that your anaesthetist will commence your epidural as soon as it is considered safe to do so. Any questions you wish to ask will be readily answered.
What are the risks?
No anaesthetic is without risk, but most patients do not suffer any serious complications. When they do occur, complications vary from mild and inconvenient (headache, backache, nausea, vomiting, shivering, drip site bruising) to the severe but very rare, such as damage to the spinal cord or nervous system, or death. The risk of developing a serious complication is very remote when the epidural is performed by someone who is experienced, and when ongoing care is provided by experienced staff in epidural management.
What are the side effects?
Once your pain has been relieved, your blood pressure can fall somewhat and this might make you feel a little light-headed or nauseated. A fall in blood pressure is usually not serious and can be easily treated. Sometimes the fall is helpful, if your blood pressure is already high. It is important not to lie flat on your back during labour because this position can affect your circulation and blood pressure and make you feel faint. You should always lie on your side, or arrange a pillow to tilt your body to one side.
What about a caesarean?
If you require a Caesarean Section, then epidural anaesthesia will allow you to remain awake and see your baby as soon as it is born. Your partner or friend can usually come into the operating room with you, and you may both nurse the baby soon after delivery. As with epidurals during labour, an epidural for Caesarean Section does not eliminate all sensation, and you will know that you are having an operation, even though you cannot feel any pain. You can also help to push the baby out at the time of delivery. After your operation is over, your epidural may be used for a day or two for pain relief; you will receive a smaller dose into the epidural at this stage, which allows you to move around.
Will it affect my baby?
Only a very small amount of local anaesthetic passes to the baby and it has practically no effect. Morphine-related drugs such as fentanyl can also pass into the baby, but the small amounts used in the epidural usually have no effect on the baby; these drugs can be easily reversed if they do affect the baby.
© anaesthetic management group 2011
Some of the above information contains extracts from the Australian Society of Anaesthetists patient information leaflet ‘Anaesthesia and you’
http://www.asa.org.au/pageBANK/documents/Anaesthesia%20You%20brochure%2023%20March%2007.pdf