Medicine, Pregnancy and Empiricism

Are doctors like scientists? Are their practices primarily guided by experiments and empiricism? Or are doctors more like artisans, unwilling or unable to test the effectiveness of many of their treatments? The Washington Post provides an interesting example of the-doctors-as-artisan model, and the results aren't pretty:

For the past 30 years or so, doctors have routinely given pregnant women intravenous infusions of magnesium sulfate to halt contractions that can lead to premature labor.

Now a prominent physician-researcher is calling on his colleagues to stop using the drug for this purpose, saying that the treatment is unproven, ineffective and potentially deadly -- an artifact of an earlier era when the standard of care was based more on pronouncements than on clinical trials.

The drug, sold commercially as Epsom salts and known to doctors as mag sulfate, causes side effects that range from highly unpleasant to lethal: nausea, blurred vision, headache, profound lethargy, a burning sensation and, in rare cases, life-threatening pulmonary edema, in which the lungs fill with fluid.

"Why has it persisted? Tradition," said David Grimes, vice president of biomedical affairs for the nonprofit public health group Family Health International, who co-authored the provocative commentary "Time to Quit" in the current issue of the journal Obstetrics & Gynecology.

While evidence-based medicine clearly has many benefits, I also think it's important to remember that turning doctors into assembly-line workers (as HMO's often do) also has clear drawbacks. A few weeks ago, Atul Gawande provided a wonderful analysis of what happened to obstetrics when it went empirical. The transition had both positive and negative consequences. Infant mortality plummeted, but C-sections (which are expensive and require an extended recovery time) now account for a third of all deliveries. The natural birth has largely become obsolete:

The question facing obstetrics was this: Is medicine a craft or an industry? If medicine is a craft, then you focus on teaching obstetricians to acquire a set of artisanal skills--the Woods corkscrew maneuver for the baby with a shoulder stuck, the Lovset maneuver for the breech baby, the feel of a forceps for a baby whose head is too big. You do research to find new techniques. You accept that things will not always work out in everyone's hands.

But if medicine is an industry, responsible for the safest possible delivery of millions of babies each year, then the focus shifts. You seek reliability. You begin to wonder whether forty-two thousand obstetricians in the U.S. could really master all these techniques. You notice the steady reports of terrible forceps injuries to babies and mothers, despite the training that clinicians have received. After Apgar, obstetricians decided that they needed a simpler, more predictable way to intervene when a laboring mother ran into trouble. They found it in the Cesarean section.

The big problem with evidence-based medicine is that it's not always clear what evidence to use. Obstetrics, for example, was revolutionized by the Apgar score, which quantified the condition of the newborn. Improving the Apgar score became the main goal of obstetricians. Unfortunately, there is no Apgar-equivalent for mothers. As a result, modern obstetrics often depends on techniques that maximize the immediate health of the infant, but aren't necessarily in the best interest of the mother. Here's Gawande:

There's something disquieting about the fact that childbirth is becoming so readily surgical. Some hospitals are already doing Cesarean sections in more than half of child deliveries. It is not mere nostalgia to find this disturbing. We are losing our connection to yet another natural process of life. And we are seeing the waning of the art of childbirth. The skill required to bring a child in trouble safely through a vaginal delivery, however unevenly distributed, has been nurtured over centuries. In the medical mainstream, it will soon be lost.

Skeptics have noted that Cesarean delivery is suspiciously convenient for obstetricians' schedules and, hour for hour, is paid more handsomely than vaginal birth. Obstetricians say that fear of malpractice suits pushes them to do C-sections more frequently than even they consider necessary. Putting so many mothers through surgery is hardly cause for celebration. But our deep-seated desire to limit risk to babies is the biggest force behind its prevalence; it is the price exacted by the reliability we aspire to.

PS. Of course, in lieu of real evidence, we could always defer to the wise judgment of Bill O'Reilly who recently claimed that it "is never the case" that a "mother's life is in danger" during pregnancy because "you can always have a C-section and do those kinds of things." I guess he's never heard of ectopic pregnancies.