Epidural anesthesia is a mode of anesthesia that numbs the body below the level of the umbilicus. The primary goals of epidurals are to eliminate pain and sensation to the areas in question.
Local anesthetics are injected into the epidural space, which is found with the help of bony landmarks on the lower back. These agents block impulses that are transmitted by the nerves before they reach the brain where they are usually processed. The onset of anesthesia is typically within a few minutes and the effect lasts for an hour or two if not maintained with further doses.
It is a relatively easy procedure to perform and its effect is, in most cases, highly reliable. It may be administered via a single injector or a catheter, which would allow for continuous infusion as necessary throughout a surgical procedure. There are several surgical procedures in which epidural anesthesia may be indicated. These include, but are not limited to, Cesarean section, orthopedic operations of the lower extremities, repair of various hernias, and gynecological as well as genitourinary surgeries. Like most invasive medical procedures, epidural anesthesia is associated with risks and side effects.
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Risks and Complications
Epidural anesthesia is a fairly safe mode of administering anesthesia. However, there are some risks involved. For instance, some patients may experience a drop in blood pressure. Therefore, this parameter must be meticulously checked throughout the procedure. Other patients may complain of chronic backache, sometimes up to several months after undergoing an epidural. Backache may be associated with the relaxation of the muscles that occurs after the epidural or it may be due to the birthing process. Evidence for the latter seems to be derived in women who gave birth without receiving epidural anesthesia.
There is a risk that a patient may experience itching due to allergy to any of the components of the epidural anesthetic used. If this itching is intractable, alternative anesthetic agents or modes of anesthesia may need to be considered. In addition to this, there is a risk of infection not only at the puncture site, but also as a result of bladder catheterization. This latter procedure is rendered necessary because of the epidural-associated loss of control of the bladder. As a consequence, these patients need to be catheterized so that the bladder may drain continuously. Some patients may experience uneven relief of pain, which may be countered by additional doses of the epidural anesthetic. Vomiting is also a risk factor, but is much less of a concern with epidural than it is with general anesthesia.
If there is inadvertent puncturing of the spinal dura during the epidural administration, the patient may experience severe headache that requires further treatment. Treatment of the puncture may be done with what is known as a blood patch, where some of the patient’s own blood is used to patch up the unwanted dural puncture hole created by the needle. This will get rid of the headache. Other complications, which are fortunately rare, include permanent nerve damage, seizures, respiratory compromise and death.
Reviewed by Liji Thomas, MD.