Obstetrical Anesthesia
What is 'spinal anesthesia'?
Spinal anaesthesia is a regional anaesthesia technique, which is sometimes used for caesarean sections and obstetrical anaesthesia. A spinal needle is placed in the lumbar spine, somewhere below the level of L2. At the level of L2, the spinal cord ends in ninety-nine percent of the population, so it's a very safe injection. Once the spinal canal is entered and cerebral spinal fluid is identified, a small amount of local anaesthetic is placed in the spinal canal, and the patient becomes numb from, approximately, the chest down. This is done for caesarean sections. If the level of numbness is from the nipples down, the patient will feel, essentially, nothing during the caesarean section. In that way, the patient can remain awake and not receive any systemic medications, and can be there for the delivery of her child. It is a very safe, regional anaesthetic technique. The side effects of spinal anaesthesia is once the needle is placed, and the spinal medication is injected, the blood pressure can decrease. We are always aware of that, and we have fluids to infuse to bring it back up; or vasopressors, medication that increases the blood pressure to bring it right back to where it was. Some patients, if the spinal anaesthetic is high, have the sensation that they're not breathing, because part of their chest is somewhat numb. We are, of course, reassuring to the mother-to-be, and get her through that period. If the mothers become very anxious, we can and will give them a sedative, but we prefer to do that after the baby has been delivered and the umbilical cord has been clamped.
What is an 'epidural'?
An Epidural is a regional anaesthetic. The epidural space is just outside of the spinal canal. It is entered using a Tuohy needle which has a bevel edge. In order to do an epidural, you pass through the skin, the subcutaneous tissue, the interspinous and supraspinous ligament, and then the ligament flavum. These all have a separate consistency and you must be able to feel these in order to pop into the epidural space. Unlike a spinal, which is driven through the Dura mata with a sharper needle to get to the end point of the cerebral spinal fluid. You do not want to see cerebral spinal fluid when you do the epidural, you are in the space just outside of the spinal canal. In that space you can infuse dilute local anaesthetic solutions so that the women in labour can have analgesia, in other words, not feel her contractions but only feel some pressure during the contractions, and allow that labour to continue. The advantage is that the mother is awake, alert and enjoys her labour. She is comfortable and has some semblance of analgesia. The epidural can be activated at the time of delivery to make the paranium numb using a concentrated and more potent solution. It can also be used if a patient has a caesarean section, not unlike a spinal where you would increase the volume of medication and make the mother numb from the chest down.
What are the risks of an epidural?
An epidural is a regional anesthetic whereby a large gauge needle is placed in the epidural space, which is just outside of the spinal canal. When placing the epidural, local anaesthetic is used to limit the amount of pain during the procedure. When placing an epidural, sometimes you have to walk off the bone or the lamina of the vertebrae. The needle can bruise that bone and there can be some post-operative discomfort in the site. Once the epidural is activated and the local anesthetic is placed in the epidural space, it's possible that the vasodilatation from the sympathectomy that the patient receives will cause a drop in the blood pressure. That will have to be treated with fluids. When the blood pressure drops after an epidural, which it rarely does, but it does, the patient may become nauseous and may become dizzy. That has to be treated with vasopressures to bring the blood pressure back to eliminate those symptoms.
Is it true that epidurals cause backache?
Epidurals can give you a backache, because it is a large bore needle that is used to place the epidural needle and the epidural catheter. This question refers to backaches that have been reported by patients several days after the epidural has been performed. The answer to that question is yes, epidural's have been implicated in backaches. Specifically, one of the medications where we use 3% Nesicaine seems to have a greater incidence of backaches. However, keep in mind that in the pain management specialty of anesthesia, many patients with back pain and/or buttock pain or leg pain are sent to pain management specialists to have an epidural to cure that pain, whereby they replace steroids in the epidural space to soothe the nerve roots that are inflamed in that area.
Can I take additional pain medication while having spinal anesthesia or an epidural?
What are the effects off anesthetics on pregnant women and fetuses?
The local anaesthetics do not have side-effects in the laboring mother if they're placed properly in the spinal canal and in the epidural space. Very little gets absorbed systemically and it should have no effect on the mother. If they're given improperly, and they do enter the circulatory system, they can cause some dizziness, some nausea, and in large concentrations can cause a seizure.
Does general anesthesia affect breastfeeding?
The answer to that question is no. There have been many studies that have looked into the effect on babies breastfed after mothers have had surgery. If the mother is awake and alert, and able to hold the baby there should not be any significant amounts of anesthetic in her breast milk to effect the baby.
