An epidural catheter, often called an epidural, is a thin, flexible tube that is inserted into the epidural space of the spine. The epidural space is the area within the spinal canal that surrounds the outer layers of the spinal cord. The epidural catheter serves as the passageway through which pain medication is delivered directly into the epidural space. It is usually taped into place to allow for the periodic administration of pain medication.
Generally, the epidural catheter is used to deliver a type of pain mediation known as a local anesthetic. The local anesthetic then works to prevent the large nerves that reside within the epidural space from transferring the message of pain to the brain, which effectively prevents patients from feeling any hurtful sensations. Commonly, an epidural catheter is used to deliver a specific class of local anesthesia, known as epidural anesthesia, after surgical procedures that involve the abdomen, pelvis, chest, or legs, and also during childbirth.
Epidural catheters are suitable for both long-term use as well as short-term use, depending upon the condition being treated. The tube is inserted into the spine via a needle. After insertion, the needle is removed and the catheter is left in place. A doctor will then connect the exposed end of the tube to an epidural pump, which is often mounted on a mobile pole near the patient’s bed and is usually programmed to continuously deliver medication. In addition, the patient is often given a hand-held device that allows them to increase the amount of medication should they require it.
The materials that epidural catheters have been constructed from have evolved over time. For instance, during the 1950s and the 1960s, it was common for doctors to fashion catheters from industrial polyvinyl chloride (PVC) or nylon. These tubes were cut to the desired length and then sterilized. After the 1960s, catheters were made out of several different materials including polyamide nylon and polytetrafluoroethylene (PTFE). Catheters that are designed for long-term use are often made out of silicon.
Several different catheter designs are common. For instance, some catheters have one single terminal eye that medication flows through. Other catheter designs incorporate lateral eyes, which are holes that occur along the sides of the catheter rather than a single hole at the end. Lateral eye catheters can either have one hole, or up to three holes. In many cases, the lateral-eye catheter designs have been shown to provide more satisfactory results than those with the terminal eye design.