The term epidural is often used as a short form for 'epidural anesthesia'. This is a form of regional anesthesia involving injection of drugs into the epidural space by means of a catheter. The term epidural is often used as a short form for 'epidural anesthesia'. Read on to find out more on this form of regional anesthesia and is often used during childbirth
The human body has a membrane (dura membrane) that covers the spine and the nerve roots in the neck. Epidural space surrounds the dura membrane. Through the epidural space, nerves travel to the neck shoulder and arms. Due to inflammation of these nerve roots, severe pain is caused in these regions. The inflammation occurs due to irritation from a damaged disc or from contract with the bony structure of the spine. An epidural injection places anti-inflammatory medicine into the epidural space. The epidural injection can cause loss of sensation or anesthesia or Loss of pain or analgesia.
This happens through blocking the transmission of pain signals through the nerves in the spinal cord. Epidural injections help reduce pain in the neck shoulders and arms. They also help in healing injury by reducing inflammation. Studies reveal that epidural injection provide short-term pain relief for patients when conservation treatments have failed.
- Patients are advised to eat a light meal a couple of hours before the procedure.
- If a patient is a diabetic, then normal pattern of eating is followed prior to the procedure.
- Routine medications may be taken by the patient.
- Patients are advised to avoid pain medications and anti inflammatory medications the day of their epidural procedure.
- Patients should not take any medications that would give them pain relief or lessen their usual pain before or after the epidural procedure.
Procedure for an epidural
As a first step before administration of an epidural, an IV is given with relaxing medications. The next step is that the physician numbs a small area of the skin with numbing medicine. As the next step, the physician then directs a small needle using x ray guidance into the epidural space. A small amount of contrast dye is injected to insure that the needle is properly positioned into the epidural space. Finally, a small mixture of numbing medicine or anesthetic and anti inflammatory injection is injected.
Conditions where epidurals are normally used
- An epidural is used for analgesia alone when surgery is not contemplated. It is important to note that an epidural is unlikely to cause loss of muscle power, though not sufficient for surgery.
- Epidurals are used as an adjunct to general anesthesia. This means that an anesthetist uses an epidural injection in addition to giving general anesthesia. This helps to reduce the patient's requirement for opioid analgesics.
- Epidurals are used in a wide variety of orthopedic surgery, general surgery, vascular surgery and gynecological surgery.
- Some exclusive surgeries like caesarean sections are performed with epidural injection. Here the patients remain awake during the course of the operation.
- Epidurals are administered as postoperative analgesia to control post surgical pain.
- Epidurals consisting of analgesics and steroids are injected into the epidural space for treatment of back pain. This helps to improve some forms of back pain.
Complications of epidural use
Epidurals are most suitable for analgesia for the abdomen, pelvis or legs. They are much less suitable for analgesia for the chest, neck, or arms. Epidurals are not possible for the head. Complications resulting from the procedure of epidural injection are rare. The following complications can occur during epidural use:
- About 1 in 20 patients suffer block failure during epidurals. Here there is either partial or total inadequate pain relief.
- Patients already suffering from coagulopathy may risk epidural hematoma when the epidural vein is injured with the needle during the procedure. The result is a bloody tap in about 1 in 30 to 50 patients.
- Accidental dural puncture with the epidural needle is another risk. This causes leak of cerebrospinal fluid into the epidural space which may in turn cause post dural puncture headache. This is not only severe but lasts for several days.
- Occasionally the catheter may get misplaced into an epidural vein and this result in all anesthetic being injected intravenously. Large doses can be toxic and also result in block failure.
- Sometimes the catheter gets misplaced into the subarachnoid space and normally cerebrospinal fluid can be freely aspirated from the catheter. If this is not recognized, then large doses of the anesthetic may be delivered into the cerebrospinal fluid resulting in high block. Rarely a total spinal, where anesthetic is delivered to the brain stream causing unconsciousness and seizures.
- Approximately 2% of patients experience side effects from the corticosteroid such as mild fluid retention.
- Back pain is reported after epidural injection in women who have given birth although medical fraternity negates this blame.
Epidurals during childbirth
Epidural injections provide immediate relief from pain in most cases. Epidurals can be used for normal vaginal birth, a vaginal birth with forceps or for vacuum extraction and sometimes even for surgical, caesarian birth. Spinal anesthesia with a smaller needle is administered for caesarian section. These days the kind of epidurals used leave the mother wide-awake and aware of everything going on during the birth of her child. However, pain relief produced by epidurals is bound to vary from one woman to another.
Risk of an epidural for mothers
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- A mother with low platelet count may make the placement of an epidural more risky.
- Sometimes due to weight problems, it becomes impossible for an anesthesiologist to find the epidural space.
- Epidurals cannot be administered if the mother is bleeding heavily or suffering from shock.
- It is observed that sometimes epidurals can lead to fetal distress and fetal malposition.
- Increased risk of forceps or vacuum extension, episiotomy and increased risk in cesarean section is observed because of epidural use.
- A study of breast feeding mothers conducted in 2006 reveals that mothers who received an epidural were more likely to experience problems in breast feeding during the first few days after delivery.