Epidurals and painkillers for labor pain relief

An epidural is a way to deliver an anesthetic so that it stops pain signals traveling from the spine to the brain. It involves injecting a small amount of anesthetic into the epidural space of the spine. The epidural space is filled with fluid and surrounds the spinal cord. Nerves that carry pain signals from the body to the brain (spinal nerves) connect to the spinal cord in certain places. The anesthetic numbs the spinal nerves, blocking the pain signals. Epidurals can't be used in women who are allergic to anesthetics or have blood clotting problems.

During labor, the medication is injected into the lumbar area, which is the lower part of the spine. If it works properly, you will no longer feel pain in the lower part of your body. But with a low dose you are still able to move your legs, or even get up and walk around with a bit of help. An epidural can also be used for partial anesthesia if the woman needs to have a Cesarean section.

Because a single injection is often not enough to last throughout the entire birth, a catheter is usually put in and then attached to the woman’s back. This thin plastic tube is pushed forward into the epidural space using a special needle. It can be used to inject more anesthetic or painkiller as needed. Doctors often do this by hand, or the catheter may be attached to a small pump that continuously supplies small amounts. Sometimes there is a patient-controlled pump. This means that you can give yourself more medication if you need it.

When epidurals are used, a small tube (cannula) is usually put into the woman’s arm as well, so that a drip can be attached to it. This is a safety precaution, for instance because your blood pressure might drop rapidly during an epidural. The cannula can then be used to very quickly supply the right drug to help increase blood pressure.

The dose of the anesthetic is usually increased gradually to avoid injecting too much at once. Pain relief is typically felt about 10 to 20 minutes later. It sometimes takes a while for anesthetists to get the injection in exactly the right place in the back, or they may not manage to do so at all.

Epidurals are very effective and can almost always relieve pain better than other medications. Most women who have an epidural feel little or no pain. About 1 out of 100 women need additional painkillers if they have an epidural. To give you an idea of what this means: About 28 out of 100 women need additional painkillers during labor if other pain relief options (not an epidural) were used first.

An epidural can be used to deliver different types of local anesthetic, which also differ in the side effects that they cause. Some medications may cause itching. If that happens, changing the medication could solve the problem. The anesthetist will explain things in detail beforehand. Common side effects include:

• Low blood pressure: In about 14 out of 100 women, the epidural causes blood pressure to drop, which can lead to dizziness or nausea.
• Fever: Epidurals cause fever in about 23 out of 100 women. By comparison, this is only the case in about 7 out of 100 women who use another type of pain management.
• Problems urinating: Epidurals can make it hard to urinate too. You might need a urinary catheter to help you urinate during the epidural. Roughly 15 out of 100 women have problems urinating because of the epidural.

Epidurals can also cause numbness or tingling in the legs. If the injection goes too deep, it might make a hole in the protective layers (dura) around the spinal cord, and spinal fluid might leak out. If too much fluid is lost, it can cause severe headaches that may last up to a few days. This happens in about 1 out of 100 women who have an epidural. Women who had an epidural were not generally more likely to have headaches than women who used other forms of pain relief during labor.

Some women are worried that epidurals might cause long-lasting back pain. But according to current knowledge, back pain isn't more common in women who had an epidural during labor than in women who used other painkillers.

Any medication that a woman uses during labor enters the child’s body as well, through the umbilical cord. This includes painkillers and anesthetics delivered through epidurals. But anesthetics don't have a stronger effect on the baby than other painkillers that might be considered for use during childbirth. Epidurals have no known long-term disadvantages. One difference, though, is that births take a bit longer on average in women who have epidurals. That could be because some babies take a longer time to move into the right position when an epidural is used.

When women have an epidural, their baby is more likely to need to be delivered with the help of instruments that use vacuum suction (a “ventouse” delivery) or forceps. These are known as assisted or instrumental deliveries.

• About 10 out of 100 women who don't have an epidural need an instrumental delivery, compared to
• about 14 out of 100 women who have an epidural.

Before a child can be born using a vacuum delivery or forceps, an episiotomy (cut made in the back of the vagina) is usually necessary, which then needs to be stitched.

Some women still feel the desire to push despite having an epidural. But because the epidural means they can't feel when it is time to push, doctors and midwives need to let them know when they should start pushing.

The epidural can be set at a dose that is low enough for the woman to get up and walk around during the first phase of labor. In this early part of labor, the cervix (opening of the womb) becomes shorter and opens fully. This is called full dilation. Walking around is supposed to help make the birth easier. But studies that compared women who walked around with women who remained lying down during an epidural found that this made no difference to the birth.

During the second phase of labor, when the baby is pushed out, women are sometimes advised to sit up a bit more, for instance by adjusting the head of the bed or leaning on their partner. It's not known whether this really affects the course of the birth, so it's best for the woman to choose the position that feels most comfortable.

Epidurals do not increase the chances of needing a Cesarean section. However, if a woman needs to have a Cesarean section, a higher-dose epidural can be used instead of a general anesthetic. This means that she can be awake to experience the birth of her child. A curtain is placed in front of the woman’s belly during the Cesarean section so that neither she nor her partner, who is sitting next to her, can see the procedure. She can remain awake enough to be able to take her baby in her arms immediately after the operation.

Spinal anesthesia works in a similar way to epidurals, but the anesthetic is injected even closer to the spinal cord: into an area called the subarachnoid space. This causes the entire lower half of the body to feel numb. Spinal anesthesia, also known as a spinal block, has a faster effect than an epidural. For this reason, it's used if a Cesarean section needs to be done but it's too late to start an epidural.

It's also possible to combine a spinal block and an epidural. But it's not clear if this has major advantages or disadvantages compared with just an epidural. The combination means that the pain-relieving effect starts faster, but it's also more likely to cause itching.

Something known as a pudendal nerve block can be performed during the second phase of labor, when the baby is pushed out. This involves injecting an anesthetic into the vaginal and perineal tissue (the tissue between the vagina and the anus). But this is usually not done unless the birth isn't progressing properly, and the child needs to be delivered with the help of a suction cup or forceps.

Painkillers can also be injected directly into the bloodstream or inhaled (breathed in). These affect the woman’s whole body, not just her abdomen. One advantage over local anesthetics is that a catheter isn't needed. But painkillers aren't as reliable as epidurals, and some also have more side effects.

Opioids can be injected into muscle tissue or “dripped” into the bloodstream using an infusion (a drip). Although opioids don't offer as much pain relief as epidurals when they are used in this way, they can help in some women. But studies show that as many as two thirds of women who are given opioids still have moderate to severe pain one or two hours later. Possible side effects include a drop in blood pressure, nausea, vomiting and drowsiness. The higher the dose, the more likely it is that the woman will experience side effects.

Opioids can sometimes affect the baby’s breathing after birth. Then the baby may be given a drug called an opioid antagonist to counteract this effect. The mother may be given this drug too. But opioid antagonists not only reduce the side effects of the opioid; they also reduce the pain-relieving effects.

Inhaling painkillers through a mask used to be a common and popular way to relieve labor pain in Germany. Laughing gas (nitrous oxide) was generally used for this purpose. It was given together with oxygen – a combination known as “gas and air.” Although this approach is still common in some other countries, it is very rarely used in Germany nowadays because it's not as reliable as other pain-relieving drugs. One advantage, though, is that women can regulate how much of it they breathe in. Laughing gas has a rapid effect, but it also wears off quickly. It may cause nausea, vomiting, drowsiness or dizziness. There are no known side effects for the baby, but more research is being done in this area.

Other medications like acetaminophen (paracetamol), non-steroidal anti-inflammatory drugs (NSAIDs) or sedatives are rarely used to treat labor pain. Compared with the other available options, they aren't very effective.