Epidural Anesthesia- what it is and how it works

In larger hospitals in the United States as many as 50% of women in labor receive epidural analgesia/anesthesia.  It is considered to be a safe and efficient form of pain relief, and is usually given if requested.

Labor should be well established

Laboring women are usually discouraged from having epidural anesthesia until their labor has been determined to be progressing well. A certain amount of cervical dilation should  have been achieved.  There is a fear that beginning an epidural too soon can slow down the progress of labor. Despite this, if a woman is experiencing intense pain near the beginning of labor, the medical staff might decide to administer an epidural.

How is the epidural given?

The epidural is a form of local anesthesia which is administered to the laboring woman through a small tube (catheter) which has been inserted into her lower back. The woman is asked to either sit up or to lie down on her side. The back is then curved forward to maximize the space between the vertebrae, so that the catheter can be inserted easily. An anesthetic such as lidocaine is first injected into the skin and interspinous ligament, (the ligament between the bones of the spine). A needle is then slowly inserted into the ligament until the epidural space is reached. At this point a catheter is inserted through the needle. A pain killer such as bupivacaine is then delivered through the catheter, causing either analgesia (pain relief) or anesthesia (loss of muscle power as well as pain relief). The larger the dose of anesthetic, the more complete is the pain relief and loss of muscle power.

Pain relief with maintenance of movement and feeling

It is possible to administer an epidural so that the woman can still move her legs and feel pressure on her perineum. This will help her later to push out her baby using cues from her body. To achieve this type of analgesic condition, an expert anesthesiologist is needed in order to determine the precise dosage of medication. Too high a dosage will result in the loss of muscle power. Too low a dosage will not provide sufficient pain relief.

Bedrest is required after receiving an epidural

Women are required to stay in bed for a time after receiving an epidural, even if she retained the muscle power in her legs throughout the delivery. Her vital signs should constantly be monitored. Sometimes an epidural can lead to a lowering of blood pressure, which can be problematic if not monitored.

For more information about epidurals, read the articles entitled "Understanding the Epidural" and "About Epidurals".