Regional Analgesics And Anesthetics

A regional analgesic provides adequate pain relief without affecting motor abilities or level of consciousness. A regional anesthetic provides not only excellent pain relief, but it also results in the loss of motor sensations, depending on the dose of medication. Both are administered into the spinal area, Over the past several years, the administration of epidurals has improved to provide greater options for laboring women. Low-dose epidurals, walking epidurals, and ultra-light epidurals allow greater movement while still providing adequate pain relief. This may help to reduce some of the negative side effects of a traditional epidural.

In addition to the epidural, the most commonly used methods of regional analgesia and anesthesia include local infiltration, the pudendal block (see Figure 7.1), the spinal (see Figure 7.2), and the combined spinal/epidural.

Epidural Anesthesia and Analgesia

The use of epidural anesthesia for pain relief during labor has increased dramatically over the past 20 years. In many hospitals, more than 70 percent of women use epidurals in labor. Epidurals have been called the “Cadillac of anesthesia.” While they are an excellent choice of anesthesia for cesarean delivery, they have side effects that you should know about before you choose one for an uncomplicated birth. For example, it can take more than 30 minutes for an epidural to be administered and take effect. Therefore, if you are well into transition, the epidural may not kick in until you are ready to push. Also, you will have to deal with the intense contractions of transition in an uncomfortable position. During the second stage, you will find it very difficult to push without feeling the natural urge. If you do receive an epidural during labor, you could request that the dosage of medication be reduced or that it be allowed to wear off so that you will be able to push effectively.

a pudendal block

Figure 7.1. A pudendal block numbs the vagina and perineum.

Among the benefits of epidurals, a woman experiencing a prolonged labor or difficult back labor may find that an epidural helps her to relax or cope better. Also, if a woman was given Pitocin during labor, she may need the relief provided by an epidural because of the increased intensity of the contractions.

Epidural medication consists of two types. Local anesthetics, or “caine” drugs (such as procaine, bupivacaine, lidocaine, and ropivacaine), provide anesthesia, the complete loss of motor control and sensation. Narcotics provide analgesia, or pain relief. The single or combined use of these two drugs can be adjusted for different results. Low-dose and ultra-light epidurals administer narcotics with little or no “caine” drugs. These allow women to retain motor function while providing adequate pain relief.

If you decide to accept an epidural, you will need to undergo several procedures. An IV will be started, and you will be given 1 to 2 liters of fluid to reduce the chance of your blood pressure dropping. You will be asked to sit on the edge of the bed or to lie on your side with your back curved while an anesthesiologist or certified registered nurse anesthetist (CRNA) administers the epidural. In addition to an IV, you will be attached to a fetal monitor and an automatic blood pressure cuff, and therefore restricted to the bed. Since your mobility and your ability to feel sensations will be greatly diminished, you may need to have a urinary catheter inserted. This is to prevent a full bladder, which could impede the baby’s progress through your pelvis.

Multiple studies have shown that epidurals prolong both the first and second stages of labor. Women are more likely to require Pitocin to improve contractions. Epidurals relax the pelvic floor muscles, which affects the rotation of the baby through the pelvis and increases the chance that assistance with forceps or a vacuum extractor will be necessary. It also increases the chance of needing a cesarean. Women having their first babies are two to three times more likely to have a cesarean for dystocia (an abnormal or pro- longed labor) if they accept an epidural before 6 centimeters dilation. If given before 2 centimeters, an epidural causes prolonged labor.

spinal needle into the spinal fluid

Figure 7.2. The spinal needle is placed into the spinal fluid, and the epidural needle and catheter are positioned in the epidural space, just outside the membrane.

Studies have also shown that if the blood pressure drops as a result of an epidural, the amount of blood flow to the uterus and placenta is reduced, and the baby’s heart rate may drop to a level that can lead to interventions and even a cesarean delivery for fetal distress.

While most caregivers state that the medication does not reach the fetus, recent studies indicate that the drugs do enter the baby’s circulation. This occurs as the medication diffuses from the epidural space into the woman’s veins and crosses the placenta. The concentration increases with the length of the epidural. The baby’s level is about one-third of the amount found in the maternal blood.

Many women are extremely satisfied with their choice of epidural anesthesia. Others, especially those who experienced side effects, are not so enthusiastic. Occasionally, an epidural does not provide adequate relief or “takes” on only one side. It can also increase the risk of postpartum hemorrhage. Among the more common side effects are itching, nausea, vomiting, a drop in blood pressure, and difficulty urinating postpartum, which may require catheterization. Residual backache, sometimes lasting for months after birth, is a common complaint. It is uncertain if this is from the procedure or, more likely, the stressful position that the woman is placed in during the second stage. Because she is numb, she cannot tell if she Is in a position that is actually harmful to her back.

Less frequently, a severe headache results from the epidural needle inadvertently puncturing the dura, the membrane that separates the epidural space from the spinal fluid. These spinal headaches, which can include neck aches and migraines, may start within 3 months of delivery and require a Mood patch to seal the puncture and eliminate the headache. This invasive procedure may require an additional epidural injection if the epidural catheter has been removed.

When an epidural is given for longer than 5 hours, one-third of women and newborns develop fevers. This may lead to admission into the intensive care nursery for diagnostic procedures, including a spinal tap and blood cultures to determine if there actually is an infection in the infant. It also results in prolonged hospitalization of the mother and baby for treatment with antibiotics for a possibly nonexistent infection.

More severe, but extremely rare, complications include an allergic reaction to the medication, convulsions from an overdose, and numbness in the chest that makes breathing difficult. Rarely, a woman must be placed on a respirator until the effects wear off.

The cost of an epidural is anywhere from $5(10 to $2,500. In an uncomplicated delivery, the charge is not always covered by insurance.

Before deciding on an epidural, you should also consider how it might affect your perception of your role in giving birth. Some women report that rather than being an active participant in the birth, they were an observer because of the epidural. While many people assume that labor is always painful and requires relief, others view birth as a normal function in which pain can be minimized or relieved by other measures. In many cases, the discomfort of labor causes a woman to find a more comfortable position, and this new position actually facilitates labor. As one anesthesiologist stated, “The practice of obstetric anesthesia is unique in medicine in that we use an invasive and potentially hazardous procedure to provide a humanitarian service to healthy women undergoing a physiological process.” Even though the incidence of severe side effects is low, every woman should carefully weigh the benefits and risks before deciding on an epidural or any medication.

Spinal (Intrathecal) Analgesia and Anesthesia

Spinal, or intrathecal, anesthesia uses “caine” drugs to provide complete loss of sensation and movement. A low spinal, known as a saddle block, can be used for a vaginal delivery, and a higher spinal can be used for a cesarean. Now, anesthesiologists are administering a narcotic into the spinal fluid for labor. (See Figure 7.2 above) This provides a rapid onset of pain relief with no loss of motor control for 3 to 10 hours, depending on the medication used. The benefits of this method over an epidural are that the onset is faster and feat it does not give one-sided or patchy relief. Also, the dose of medication is very small to reduce the risk of toxicity. The side effects of narcotics include nausea, vomiting, urinary retention, itching, prolonged labor, and respiratory depression. A spinal headache may also occur.

Hints for the Labor Partner Prior to labor:
  • Discuss your feelings with your partner about using or not using medication as a labor tool.
  • Share your desires/birth plan with your partner's caregiver.
  • Learn all you can about the options available if your partner's labor does not progress as expected.
  • Make sure you understand the risks and benefits of epidurals and the medications used during labor.

Combined Spinal/Epidural Analgesia

During the administration of a combined spinal/epidural, the anesthesiologist first inserts an epidural needle. Through the epidural needle, he guides a thinner, but longer, spinal needle past the epidural space and dural membrane, and into the spinal fluid. A small dose of narcotic is given, and the spinal needle is withdrawn. An epidural catheter is then threaded into place, the epidural needle is withdrawn, and the catheter is taped to the woman’s back.

As the spinal begins to wear off, the anesthesiologist can provide continuous medication through the epidural catheter. As long as the medication used is a narcotic, the woman will retain muscle control and can walk. A “walking epidural” does not provide as deep a level of pain relief, and the woman can perceive the pressure of the contractions. This can be especially beneficial during the second stage of labor. If deeper anesthesia becomes necessary, “caine” drugs can be added to the epidural.

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