What you need to know about epidurals

Q: What exactly is an epidural?

An epidural is a needle placed between the bones of the spine of the lower back. The needle is used to locate a space just outside the sac where the spinal cord and its fluid are located. A fine plastic tube is threaded into the space and the needle is removed (like an intravenous). Once the tube is in place, the anesthesiologist can deliver freezing medicine and pain-killers into the epidural space, freezing the nerves to the uterus the way a dentist freezes the nerves to a tooth.

Once the tube is in place, it will be connected to a pump that delivers a constant flow of the medication to keep you comfortable. As long as the epidural does not fall out, it can be used as long as labour lasts. It will not wear off. If the epidural falls out or does stop working for some reason, it can always be redone.

Q: How and when is it administered?

An epidural can be administered at any time after your obstetrician has determined that you are in fact in labour. You cannot get it too early in labour and you can receive one up until it is time to actually deliver the baby. 

Once you have requested an epidural, an anesthesiologist will see you as soon as he or she is able. The doctor will take a medical and obstetric history, review your medical chart and discuss the epidural, risks, and complications with you. Once you have consented to have the epidural, the doctor will position you in either the sitting position or lying on your side. The doctor will show you how to arch your lower back so as to make it easier to perform the procedure. Your lower back will be cleaned with a cold solution and a plastic drape placed over the area to keep it clean. The doctor will feel your back, looking for the best spot to place the epidural then freeze the skin at that spot. You will feel a little prick (like a bee-sting) followed by some burning (the freezing medicine burns a bit when it is first injected). After that, the epidural needle will be inserted. This will feel like a dull pressure in your lower back but should not be overly uncomfortable. When the plastic tube is placed, people occasionally feel an electric shock in one of their legs (like hitting your funny bone). This is brief and of no significance. Once the tube is taped in place, you will not feel it and can adapt any position which is comfortable.

Q: What are the risks and side effects involved?

The major risks include very rare complications such as nerve damage, paralysis and toxic drug reactions, which may lead to a loss of consciousness or seizures. These are exceptionally rare cases. Minor risks include itchiness from the epidural pain killers, weak or heavy legs, and bruising from the needle (which may cause a sore back). There is a small risk of getting a spinal headache a day or two later, but it goes away.

Q: Will I be able to feel any pain at all?

Pain is very subjective and no two labours are alike. Most women with an epidural are very comfortable for most of their labour. They may have breakthrough contraction pains that are treated with additional epidural medication. As labour progresses, some women experience a lot of vaginal, rectal and perineal pressure. Again, this is usually treatable. When it is time to deliver, some pressure sensation is required to give you an urge to push. Some women find this uncomfortable.

Q: Can all women have an epidural for labour?

Nearly all women can receive an epidural for labour. There are some medical conditions that may contraindicate epidurals such as active infections, bleeding disorders, medications that thin the blood, spinal malformations (spina bifida), and some previous major spinal surgeries. Many of these are relative and prenatal consultation with an anesthesiologist is recommended.

Q: Can you still urinate if you have an epidural?

Ideally, most women would still be able to sense when their bladder is full and pass urine themselves. They should even be able to walk to the bathroom with some assistance. Some cannot and require a catheter (a small tube inserted through the urethra into the bladder) to empty it. This is not painful because of the epidural. Some hospitals still routinely catheterize patients with epidurals.

Q: People say if you have a tattoo on your back, you can’t have an epidural. Is this true?

This is not true. The theoretical risk is the introduction of tattoo dye into the spinal canal. To date, there are no known reports of complications related to placement of an epidural through a tattoo. It is not usually an issue because most of the time, an epidural can be placed without puncturing the tattoo at all. If this is not possible, a small needle can be used to make a hole prior to inserting the epidural needle to decrease the risk of picking up some ink. In spite of this, some anesthesiologists may still refuse to do an epidural through a tattoo.

Dr. Eric Goldszmidt is assistant professor, Department of Anesthesia, at the University of Toronto. He is also staff anesthesiologist at Mount Sinai Hospital.