Low-Dose Epidurals Deliver
Lighter anesthetic eases pain with fewer complications
FRIDAY, July 6, 2001 (HealthDayNews) --Low doses of injected painkillers during labor are as effective as conventional epidurals and produce better results, says a new study.
English scientists say cutting the dose of epidural anesthetic in half provides ample protection from pain while preventing nearly a quarter of all surgically-assisted vaginal deliveries. Assisted deliveries have been associated with an increased risk of trauma to both mother and baby.
Many women ask for epidural injections to dull labor pains. However, high doses of the anesthetic can can paralyze the pelvic muscles and weaken pushing.
Low-dose (or "walking") epidurals preserve mobility and help women push more strongly, shortening their time in labor, say the researchers.
"The main purpose of giving an epidural is to provide pain relief, and the pain relief that was achieved was identical" in both low- and high-dose injections, says the lead author, Dr. Andrew H. Shennan of St. Thomas' Hospital in London. "There seems to be very little reason to justify using an outdated technique," says Shennan, who is a senior lecturer in obstetrics and maternal and fetal medicine.
In the United Kingdom between a quarter and a third of the 150,000 women who undergo epidurals continue to receive the high-dose form, Shennan says. In America and Canada the percentage may be even greater, he says.
The study, reported in the July 7 issue of The Lancet, compared two low-dose epidural methods in 1,054 first-time mothers who asked for the injections during labor.
One-third received low-dose combined spinal epidurals, in which doctors shoot painkiller directly into the base of the spine, then add more as needed; another third were given low-dose infusions to continuously pump anesthesia into the spinal fluid. The others received conventional-dose epidural injections, consisting of 0.25 percent of the anesthetic agent bupivacaine. The low-dose solutions contained 0.1 percent bupivacaine, a difference of about 60 percent.
Both low-dose methods increased the likelihood of an unassisted vaginal delivery from 35 percent to 43 percent, or about a 22 percent improvement over conventional epidurals, the researchers say. The rate of cesarean section was the same for each group.
Low-dose epidurals didn't seem to affect babies in the study, although those born to women who received the infusions had a somewhat higher risk of needing significant resuscitation upon delivery.
Shennan says that's likely related to the use of the drug fentanyl in low-dose epidurals. Fentanyl is an opioid that crosses the placenta and can temporarily suppress the newborn's activity. "In spite of this, there wasn't any increased risk of the babies ending up in special care" after exposure to fentanyl, he says.
What To Do
Don't wait till you're in labor to talk about pain relief with your doctor. Find out what's available in your hospital.