Regional Anesthetics for Labor Pain
Systemic medications are distributed via the bloodstream to all parts of the body. Yet most of the pain of labor and delivery is concentrated in the uterus, vagina, and rectum. So regional anesthesia is sometimes used to deliver pain medication to those specific areas.
Medications used in regional anesthesia can be a local anesthetic (like lidocaine), a narcotic (such as those in the preceding section), or a combination of the two. Commonly used techniques for administering regional pain relief include epidural and spinal anesthesia and caudal, saddle, and pudendal blocks.
When it comes to relieving labor pain, there is nothing like an epidural. Epidural anesthesia is perhaps the most popular form of labor pain relief. Almost universally, women who have had it say, “Why didn’t I get this earlier?” or “Why was I hesitant about this?”
An anesthesiologist with special training in epidural catheter placement must administer an epidural, so epidurals may not be available in every hospital. This is definitely something you want to find out ahead of time so there are no surprises on the day (or night) of the big event!!
With an epidural, a tiny, flexible, plastic catheter is inserted through a needle into your lower back and threaded into the space above the membrane covering the spinal cord. Before inserting the needle, the anesthesiologist numbs your skin with a local anesthetic.
While the needle is going in, you may feel a brief tingling sensation in your legs, but the process really isn’t painful for most women. After the catheter is in place, medication can be sent through it to numb the nerves coming from the lower part of the spine — nerves that go to the uterus, vagina, and perineum (the area between the vagina and anus).
The catheter (not the needle) stays in place throughout labor in case you need what’s called a top-up dose of the anesthetic to get you through the rest of labor and delivery.
A major advantage of epidural anesthesia is that it uses smaller doses of pain medication. However, because your sensory nerves run very close to your motor nerves, large doses of anesthetic can temporarily affect your ability to move your legs during labor.
The amount and type of medication you need can be adjusted according to the stage of labor you’re in. During the first stage, pain relief focuses on uterine contractions, but during the second (pushing) stage, pain relief focuses on the vagina and perineum, which are distended by the baby passing through. Epidurals can also make repairing a tear, or episiotomy, much more tolerable.
Years ago, anesthesiologists wouldn’t give epidurals during early labor because it confined patients to their beds for the remainder of their labor. Recently, however, walking epidurals — the kind that allow you to walk around, because they use medications that have little or no effect on motor function — have become more popular for this often painful stage of labor. Some anesthesiologists, however, question the effectiveness of this type of epidural in relieving pain.
Epidurals can also relieve pain in cesarean deliveries, although different medications in different doses are used. In fact, epidurals are very popular for cesareans because they enable the mother to be awake during delivery and to experience her child’s birth. In cases in which cesarean delivery is an emergency or when the mother has blood-clotting problems, however, an epidural may not be possible.
Doctors once thought epidurals, especially if placed too early, prolonged labor and increased the need for forceps, vacuum-assisted, or cesarean delivery. For this reason, many practitioners were reluctant to recommend epidurals to their patients. Most doctors today accept that these problems are negligible when an experienced anesthesiologist places the epidural after labor is well established, and that the benefit outweighs the risk.
Sometimes the epidural takes away the sensation you feel when your bladder is full, so you may need a catheter to empty your bladder. In some cases, the epidural may block motor nerves to the point where you have difficulty pushing. You also may experience a rapid drop in blood pressure that can lead to a temporary drop in the baby’s heart rate.
Overall, pain control simply makes the whole experience of labor and delivery much more enjoyable for the mother and her partner (and the person doing the delivery, too!).
Spinal anesthesia is similar to an epidural except that the medication is injected into the space under the membrane covering the spinal cord, rather than above it. This technique is often used for cesarean delivery, especially when a cesarean is needed suddenly and no epidural was placed during labor. The information already discussed about epidurals (regarding the amount of medication needed and the risks involved) applies to spinal anesthesia, too.
Caudal and saddle blocks
Caudal and saddle blocks involve placing the medications very low in the spinal canal, so they affect only those pain nerves going to the vagina and perineum. These methods have a more rapid onset of pain relief, but the medication wears off sooner.
Your doctor can place a pudendal block by injecting an anesthetic inside the vagina, in the area next to the pudendal nerves. This technique numbs part of the vagina and the perineum, but it does nothing to relieve the pain from contractions.