Childbirth can be painful for women. However a new study shows that women would rather control their own intake of epidural infusion, than be connected to a continuous flow. In fact, new finding show that less painkiller is actually distributed this way, making the potential harmful side effects of the drugs kept to a minimum, and mothers are still feeling equally as fine.

The term epidural is often short for epidural analgesia, a form of regional analgesia involving injection of drugs through a catheter placed into the epidural space. The injection can cause both a loss of sensation (anaesthesia) and a loss of pain (analgesia), by blocking the transmission of signals through nerves in or near the spinal cord.

The epidural space is the space inside the bony spinal canal but outside the membrane called the dura. In contact with the inner surface of the dura is another membrane called the arachnoid mater. The arachnoid encompasses the cerebrospinal fluid that surrounds the spinal cord.

Michael Haydon, M.D., one of the study’s authors, stated at the Society for Maternal-Fetal Medicine’s (SMFM) annual meeting in San Francisco this week:

“We conducted the first double blind study, excluding inductions and including only women who were delivering for the first time, so that we could get a good sample of women with similar labor patterns. Though patients in each group showed equal satisfaction, we did note that there was more pain during the final delivery stage in the patient-controlled epidural analgesia (PCEA) group. The next step is to look at shortening the lock-out intervals between doses, or having the option of administering additional analgesia during the final pushing stage.”

Women often receive a continuous epidural infusion of analgesic during labor. This can lead to prolonged labor and an increase in assisted vaginal delivery. Several pain management studies have been done to begin looking at how much analgesia women use and what their pain experience is like when they are able to administer it themselves.

The study concluded that PCEA resulted in 30% less analgesia being used while maintaining high maternal satisfaction. There was also a trend toward reduction in instrumented vaginal deliveries in the PCEA only group.

A patient receiving an epidural for pain relief typically receives a combination of local anesthetics and opioids. This combination works better than either type of drug used alone. Common local anesthetics include lidocaine, bupivacaine, ropivacaine, and chloroprocaine. Common opioids include morphine, fentanyl, sufentanil, and pethidine (known as meperidine in the U.S.). These are injected in relatively small doses.

In addition to blocking the nerves which carry pain, local anaesthetic drugs in the epidural space will block other types of nerves as well, in a dose-dependent manner. Depending on the drug and dose used, the effects may last only a few minutes or up to several hours. Epidural typically involves using the opiates fentanyl or sufentanil, with bupivacaine, Fentanyl is a powerful opiate with potency and side affects 80 times that of morphine. Sufentanil is another opiate, 5 to 10 times more potent than Fentanyl. Bupivacaine is markedly toxic, causing excitation: nervousness, tingling around the mouth, tinnitus, tremor, dizziness, blurred vision, or seizures, followed by depression: drowsiness, loss of consciousness, respiratory depression and apnea. Bupivacaine has caused several deaths by cardiac arrest when epidural anesthetic has been accidentally inserted into vein instead of epidural space in the spine.

Haydon also noted that, in future, he expects the technology to move in the direction of automated analgesia delivery in response to patient need.

Source: News Release

Written by Sy Kraft, B.A.