Generally an epidural will be administered as follows:
- The anaesthetist will take a medical history and perform a brief examination prior to inserting the epidural.
- An intravenous line (or “drip”) is inserted.
- You will then be positioned either on your side or sitting up on the edge of the bed and your back will be cleaned with an antiseptic solution. Local anaesthetic is injected into the skin in the lower back.
- The catheter is then inserted via a needle positioned between the vertebrae. It is important that you remain as still as possible during this stage. It usually takes a few minutes and can be timed to occur between contractions.
- Once inserted the catheter is taped to your back and the first dose of local anaesthetic is administered via the catheter.
Initially it takes about 10 minutes for the first effects to be noticed. Contractions usually first seem shorter and then more comfortable.
During labour the dosage of local anaesthetic is regulated such that pain relief is provided but the ability for you to push during delivery is retained.
- Superior pain relief. An epidural currently provides the best method of decreasing the pain of labour and vaginal delivery.
- Complex pregnancies. For those women whose pregnancy is more complex than normal (e.g. twins, breech presentation, previous Caesarian section) the presence of an epidural allows for a more controlled delivery as well as providing the back up of rapid conversion to Caesarian section if required.
- Painful labour can be a physically stressful experience for the mother with this stress passed to her baby. The presence of good pain relief can decrease this stress response.
Lowering of blood pressure: The presence of local anaesthetic in the epidural space often lowers the mother’s blood pressure. This may result in a feeling of faintness or nausea. It is for this reason that before and after an epidural is inserted, the mother’s blood pressure is checked and the baby’s heartbeat monitored. Fluid and medication can be given to the mother, via the intravenous line, to counteract any drop in blood pressure if it were to occur.
Headache: Very occasionally the needle used to insert the epidural can make a small hole in the covering of the fluid surrounding the spinal cord. This allows some fluid to escape resulting in the mother experiencing a headache that may take some time to develop (over several days) and can be persistent. This is estimated to occur about once every 200 epidurals. If the headache does not respond to bed rest and simple analgesia, the most successful treatment is to repeat the epidural, but this time inject some of the mother’s own blood into her back to seal the hole (“Epidural Blood patch”).
Inadequate Pain Relief: Occasionally it may be extremely difficult or impossible to achieve a satisfactory degree of pain relief. A ”patchy block” may develop where some relief occurs or it could fail completely. In this situation there may be the opportunity to repeat the insertion or otherwise alternative methods of pain relief may be required.
High Block: This describes the situation where the level of the epidural block extends higher than expected, possibly resulting in numbness and weakness of the arms and muscles of breathing. Anaesthetists are fully trained to deal with this very rare eventuality if it were to occur.
Back Pain: There is no shown association between the occurrence of long term back pain as a result of having an epidural. Women often have some discomfort following childbirth, but the epidural has no effect on this.
Nerve Injury: This is the most serious complication of an epidural but also extremely uncommon. It may occur due to the epidural needle or catheter directly injuring a nerve, due to development of an infective abscess or through bleeding into the epidural space. For this reason, women who have a significant coexisting infection, have a bleeding disorder or who are on medications which alter blood clotting may not be suitable to have an epidural block. If a nerve injury were to occur it may be temporary but can, in extremely rare situations, lead to permanent loss of function of the legs, bladder or bowel.