Each of these different situations carries with it different anesthesia concerns.
Scheduled C-sections are the easiest and most relaxed for everyone concerned. The most common type of anesthesia used is a regional anesthetic. The two most common types of regional anesthesia for C-sections are spinal blocks and epidural blocks. What the patient experiences during the actual placement of either of these blocks is about the same. The real differences occur after the placement.
General anesthetics are increasingly rare in the US for scheduled C-sections. We tend to reserve general anesthesia for three situations:
All this is because spinals and epidurals are a little safer statistically for C-sections. It is a small difference in risk, but risk we avoid if possible.
You, the patient, will be prepared for surgery by a nurse or nurses. Your MD anesthesiologist will meet you either in the preparation room or in the operating room to discuss your health history, the procedure and answer any questions. Once in the operating room, the nurse and anesthesiologist will put the standard anesthesia monitors on you. These include blood pressure, EKG and pulse oximeter. Then you will be asked to either sit on the side of the bed and slump over or lie on your side and curl up in the full tuck (fetal) position. Your back will be cleaned off with a room temperature, sterilizing solution, usually betadine. If you know that you have an allergy to iodine on your skin, please inform your anesthesiologist. Also, we appreciate an extra reminder just as we are about to begin the procedure, because we are human and therefore creatures of habit. It is our routine to use Betadine. The skin and underlying tissues are then numbed with an injection of lidocaine in the low back in the space between spine bones somewhere between the second lumbar vertebra and the top of the sacrum bone. A very skinny needle is used, but that first injection does sting for about 10-15 seconds. There is usually a second injection in the same spot but a little deeper. It tends to sting less than the first one. The rest of either procedure doesn’t usually hurt much, if any. The next step is where the differences between spinal and epidural occur.
A very thin (25 -27 gauge) needle is placed through the numb spot into the spinal fluid. A special numbing medicine formulated for spinal anesthesia is injected through the needle, directly into the spinal fluid and the needle is removed. Because the spinal cord is directly bathed in numbing medicine, you will begin to get numb almost immediately from mid-chest down. Within about 5 min the numbness is complete.
The most common side effect of both spinal blocks and epidurals is a drop in blood pressure. Not only do the blocks numb the nerves that carry pain signals to the brain, but they also numb the nerves that carry signals to the blood vessels to keep the vessels tight or constricted. Blocking these nerves makes the muscles in the walls of these vessels relax which in turn, causes blood to pool in these same vessels. That means less blood returning to the heart and therefore, lower blood pressure (BP). The lower blood pressure causes people to feel like they are about to pass out. This can be very frightening. A low BP can also cause nausea and vomiting. This drop in BP is very common in C-sections. We make an effort to prevent it by giving IV fluids (1 – 1.5 liters) quickly right before going to the C-section Room. That doesn’t always totally prevent the drop in BP.
If the block gets high enough on your chest that your fingers start to tingle, that could cause you to feel short of breath. Although most of the work of breathing is done by the diaphragm which is protected from the spinal because it gets its nerve supply from high in the neck, blocking the nerves to the muscles between the ribs causes the sensation of not being able to get a good, deep breath. If the block gets a little higher, it can become difficult to cough and swallow. These sensations can be somewhat frightening, but are not life-threatening. After the baby is out, the shortness of breath will usually go away or get significantly better within a matter of minutes.
After the baby is out, it is common to experience an aching sensation in your chest and get a stuffy nose.
When the spinal block is placed, a small dose of morphine is usually injected with the spinal numbing medicine. It provides a good, base of pain relief for the first 18 – 24 hours. Some women don’t need any other pain medicine during this time. Others need supplemental medication which can be given through the IV or in the form of pills.
The major issue with spinal morphine is itching. A small amount of the morphine in the spinal fluid floats up to the head and directly stimulates the “itch center” in the brain. For some women this is no big deal, but others require medication to treat the itching.
The epidural needle is placed between two spine bones in the low back, usually somewhere between the 2nd lumbar vertebra and the sacrum (L2 to S1). The tip of the needle is inserted into what we call the epidural space. It isn’t really a space in everyday life. It is really just the contact between the dura mater and the ligament that touches it on its outward-facing surface. When the needle goes through the ligament, it creates the space by “tenting” the dura. Dura mater is a term you might have learned for a test in high school biology and then forgot as soon as the test was over. It is the outermost of the three layers that cover and protect the brain and spinal cord. A thin plastic tube (epidural catheter) is slipped into the epidural space through the needle and the pain-relieving medicine is injected through the catheter. Once the medicine is in the epidural space, it takes 15 – 30 minutes before the full effect is obtained, depending on which drug is used.
The side effects are essentially the same as for a spinal, but to a lesser degree. Since the block takes effect much more slowly, the side effects are less prominent. Patients are less likely to be nauseated, short of breath or feel the aching in their chests after the baby is out.
Since the side effects are generally similar yet less prominent with an epidural compared to a spinal block, it would seem logical that epidural is the obvious choice. It turns out that such is not the case for most anesthesiologists in the U.S. This is due mostly to the increased failure rate of epidurals vs. spinal blocks, as well as to the extra time epidurals require.
A certain number of epidurals placed for C-sections end up being inadequate, meaning the patients still have some degree of pain during the procedure. There may be spots that don’t get totally numb and often patients report that they feel more pulling and tugging than they had been anticipating. Some epidurals for C-section just don’t work and re-doing an epidural after spending 40 minutes or more trying to make the first one work just isn’t effective use of facilities or personnel.
Another issue with epidurals is that they take a lot longer to work than spinal blocks do. Epidurals may add another 15 minutes on to the operating room time for a scheduled C-section. In this day of trying to eliminate waste, that is a problem.
As with a spinal, we do give morphine in the epidural for post-operative pain control, but it isn’t nearly as effective as spinal morphine.
During the surgery, you can expect to feel some pulling and tugging or pressure. That is totally normal, but you should not feel pain. If you do, you need to tell your anesthesiologist. He or she can give you pain medication and sedatives through your IV to relieve the pain. We will do this at any time you request it. If you tell us the pain is tolerable, we will wait until the baby is born before sedating you because the drugs will also go to the baby. We prefer not to make the babies sleepy right before they are born. We want them to be wide awake so they can get that first breath going. After the baby is out, our anesthesiologists are more than happy to give you pain medicine or sedation as needed to control your pain or anxiety.
When the baby is actually taken out of the uterus, the assistant surgeon will push on your upper belly to help push the baby out. This can be uncomfortable, similar to having a 3-year-old sitting and bouncing on your chest.