Labor Wards Looking at Laughing Gas

April 27, 2011— -- Rapid contractions left Anna Jaeger desperate for something more than the distraction of the jacuzzi tub during the slowly progressing delivery of her first child.

Hoping to retain some sensation and avoid an epidural, she turned to an analgesic option available to few U.S. women -- nitrous oxide, better known as laughing gas.

"It was wonderful," she said, laughing at the recollected relief. "I told the anesthesiologist I loved her, it helped that much."

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That's a pretty typical response, according to nurse midwife Judith Bishop, CNM, MPH, who assisted with the delivery at the University of California San Francisco Medical Center.

UCSF is one of only three centers in the country that offer nitrous oxide during labor and delivery. But that may be changing with a grassroots movement driven by nurse midwives to give women an intermediate option short of an epidural.

'Good Enough' Relief

Obstetric analgesia has a limited range concentrated at the two extremes: nonmedical tools like massage and hot tubs that make women more comfortable and epidural infusions that block all feeling below the administration site.

Opioid painkillers are also available but typically don't do much for labor pain, noted Suzanne Serat, CNM, MSN, a nurse midwife at Dartmouth-Hitchcock Medical Center in Lebanon, N.H.

"In studies that look at how much pain relief there is from different tools, tubs rate higher than narcotics," she explained in an interview with MedPage Today.

Nitrous oxide may bridge that gap with modest pain relief.

"They won't say it makes a tremendous dent in their pain," Bishop told MedPage Today, but it often provides enough distance and relief for the quintessential response "It still hurts but I don't care."

Specialized nitrous oxide equipment used in the delivery room fixes the oxygen-to-nitrous oxide ratio at 50/50 and the woman holds the mask in her hand, controlling when and how much anesthetic she gets.

These measures ensure that the gas never becomes anesthesia, as when used in the operating room or dental office, and eliminate concerns about oxygenation for mother and baby, Bishop noted.

The quick-on, quick-off effect (the body doesn't metabolize nitrous oxide) makes it a flexible tool in the delivery room, added Serat, who is part of a team at Dartmouth evaluating its potential use there.

Women can get up to run to the bathroom, for example, unlike an epidural which tethers them to the bed, she noted.

It also provides a quick option for women progressing too rapidly through labor to get an anesthesiologist in the room to administer an epidural or for those planning a "natural" unmedicated birth but who hit a rough patch and need some relief, Bishop pointed out.

Nitrous may have the most promise for free-standing birthing centers or those without 24-7 availability of an anesthesiologist, noted Craig M. Palmer, MD, of the University of Arizona in Tucson and chair of the obstetric anesthesia committee for the American Society of Anesthesiology.

A Labor of Love

For these reasons, nitrous oxide has been gaining a following among nurse midwives, and the burgeoning interest has no greater cheerleader than Judith Rooks, CNM, MS, MPH, the former head of the American College of Nurse Midwives and professor emeritus at Oregon Health & Science University in Portland.

"It was so striking to me that women in other countries had this choice and women in the U.S. didn't," she said in an interview.