Women commonly experience lower back pain during pregnancy and in the early weeks after the birth of their baby. The relationship between backache and having an epidural is a controversial one. It has long been thought that having epidural was the direct cause of developing backache in up to one third of women. In the first few days after the birth this is probably so, but as far as long term backache, the picture is not so clear.
There is now mounting evidence that backache after an epidural may be more linked to the woman lying in an awkward position for a long period of time, rather than the actual procedure itself. As the woman’s sensations are reduced (or removed) from the lower back with an epidural, it is hard for her to give feedback from any back discomfort. Caregivers should be aware of the woman’s positioning and how she is moved when the woman has an epidural anaesthetic.
Be aware that back pain is very common for many women after childbirth, especially due to the abdominal muscles being weakened. Whatever the cause the new mother should do postnatal exercises and take care with lifting and her posture.
Occasionally the epidural needle will advance beyond the epidural space and inadvertently pierce the dura mater tissue to reach the spinal canal and the spinal fluid (about 1% of the time). This means that the epidural has then become a spinal anaesthetic. This in itself is not a major complication, except that an epidural catheter cannot be left in place and the woman is then subject to the possibility of experiencing a spinal headache after the birth.
A spinal headache is caused by small amounts of the cerebral spinal fluid (or CSF), leaking from the spinal puncture site, once the needle is removed. The leakage of CSF fluid reduces the fluid pressure around the spinal cord and the brain, sometimes causing a severe headache.
Local anaesthetic in the vein
Sometimes the local anaesthetic can be unintentionally injected into a vein and enter the woman’s blood stream, rather than the epidural space. This is because the blood supply to the area is increased during pregnancy. Local anaesthetic in the blood stream can cause fits and in some cases is a life-threatening complication. Measures are taken by the anaesthetist to try and prevent this but on rare occasions it can still happen.
Adrenaline (epinephrine) is sometimes used in combination with the local anaesthetic. This is aimed at prolonging the pain relieving effect of the epidural, as well as giving the anaesthetist some early signs (such as a rapid pulse), before too much of the local anaesthetic is injected into the vein.