An epidural is a frequent selection for pain management during childbirth, and the needle involved can be a source of apprehension. Many expectant parents express concern about the size of the epidural needle and the procedure. Knowing the specifics of the equipment and process can help demystify the experience and ease these worries.
Epidural Needle Dimensions
The needle used for an epidural is a Tuohy needle, designed specifically for the procedure. These needles are 17 or 18-gauge with a standard length of about 3.5 inches (9 centimeters), though longer versions are available for patients with more tissue on their back. The gauge number indicates the needle’s diameter, where a lower number means a wider needle.
For comparison, an 18-gauge needle is wider than those used for blood draws and is comparable to the thickness of uncooked spaghetti. This larger diameter is necessary for its function, and the design includes depth markings to help the anesthesiologist gauge insertion depth.
The Role of the Needle in the Procedure
A primary reason for the epidural needle’s size is that it is hollow and functions as a guide for a smaller, flexible tube called an epidural catheter. The Tuohy needle is advanced into the epidural space, an area that surrounds the spinal cord. Once the anesthesiologist confirms the needle is in the correct position, the thin catheter is threaded through the center of the needle.
After the catheter is placed, the epidural needle is completely withdrawn and does not stay in the back. Only the soft, flexible catheter remains taped in place to deliver pain-relieving medication continuously.
Managing Pain During Placement
The thought of a large needle can cause anxiety, but the procedure is designed to minimize pain. Before the epidural needle is inserted, the anesthesiologist administers a local anesthetic to numb the area on the back. This is done with a much smaller needle, injecting a medication like lidocaine into the skin and deeper tissues.
This initial injection feels like a small pinch followed by a stinging or burning sensation as the numbing medication begins to work. This is often compared to the sensation of getting a cavity filled at the dentist’s office. Once the area is thoroughly numbed, the placement of the larger epidural needle is felt as pressure rather than a sharp pain.