Epidurals and Labor
Epidural use for labor pain during pregnancy is effective, safe and widely practiced. Childbirth can be very painful. Various treatment options, both pharmacologic and non-pharmacologic, are useful in treating this pain, however, epidural analgesia is typically the most effective method of controlling of labor pain.
What is a Labor Epidural?
A labor epidural is an epidural used in pregnancy to treat labor and delivery pain.
As with all epidural procedures, the term “epidural” refers to the anatomical space surrounding the spine where drugs are delivered to provide anesthesia and pain relief. Epidurals are performed by entering and injecting drugs to this epidural space. Epidurals can be performed as a one time “single shot” injection through a needle or repeatedly or continuously through a small caliber tube (catheter). Labor epidurals are typically “continuous” epidurals, using a catheter to infuse medicine throughout labor and delivery until the epidural is no longer needed.
Continuous epidurals use an infusion pump to deliver a constant amount of drug over time and provide continuous pain control. Many modern infusion pumps allow the patient to deliver a bolus (“top-up”) dose of the infusing drug(s) on top of the continuous infusion. This “top-up” dose delivers addition drug to the epidural space and enhances the anesthetic depth and pain control, which may be helpful treating increased pain during the progression of labor. Epidural infusions with this patient demand feature are known as PCEAs or Patient Controlled Epidural Anesthetics.
How are Labor Epidurals Placed?
Labor epidurals are typically placed and started after active labor has begun. Intended for use in a hospital-like setting, they should not typically be placed if there is a chance the patient is not in active labor and will not be admitted to the hospital.
Although some believe that patients should wait for a specific cervical dilation (5cm for example) prior to receiving a labor epidural, there is little evidence to support this practice.
It is my and many anesthesiologist belief that consideration of labor epidural risks and benefits favors earlier rather than later placement. Epidurals placed earlier in allow for greater patient comfort, use of lower initial concentrations of local anesthetics and opioids, and tend to be easier to place for the practitioner. Lower patient levels of catecholamines (stress hormones) may also benefit early placement.
Once a patient is deemed to be in active labor and desires epidural placement, an IV (intravenous line) is often placed. IV access allows for hydration prior to epidural dosing, and the delivery of certain medicines should they be necessary during epidural use. Although commonly practiced, hydration prior to epidural placement, as it is currently practiced, probably provides limited value. Studies suggest the need for at least 2 liters of rapidly infused IV fluid (balanced salt solution) to provide any meaningful benefit.
After IV access and hydration, most patients are positioned in a seated or lateral lying position for the actual placement of an epidural catheter. Labor epidurals are typically placed in the low back (lumbar) region of the spine. In preparation for placement this region of the back is sterilized and drapped. Local anesthestic is then injected into the skin and soft tissues below the skin. A specialized needle is inserted through the area numbed by the local anesthestic injection and advanced to the epidural space. Once in the epidural space a soft epidual catheter is threaded through the epidural catheter into the epidural space. The epdiral needle is then withdrawn, while keeping the epidural catheter in the epidural space. The catheter is then secured to the skin.
Local anesthestics and opioids — typically a mixture of a long acting local anesthestic and a synthetic opioid — are injected through the epidural catheter. Once the initial dose of the epidural drug solution is given, the epidural catheter is typically connected to a pump to continuously delivery this solution throughout the labor and delivery process.