Computer-Driven Pain Patch Shows Promise

Patient-controlled technology might replace IV morphine pump in hospitals

TUESDAY, March 16, 2004 (HealthDayNews) -- A credit card-sized, computerized analgesic skin patch performed just as well as traditional IV morphine pumps in delivering patient-controlled pain relief after surgery, a new study shows.

The study findings, published in the March 17 issue of the Journal of the American Medical Association, may move the hi-tech device closer to full U.S. Food and Drug Administration approval.

"Head to head, patients evaluated each method of pain control as relatively therapeutically equivalent," says lead author Dr. Eugene Viscusi, director of acute pain management at Thomas Jefferson University, in Philadelphia.

In decades past, patients recovering from surgery relied on nurses and doctors to supply and calibrate their pain control. But according to pain expert Robert Coghill, of Wake Forest University, this "one size fits all" approach wasn't ideal.

"We know that different people have different experiences of pain from the same [injury]," he says. "Some people are under-medicated and have too much pain, while other people are going to be over-medicated and have too many side effects."

The development of Patient-Controlled Analgesia (PCA) about 30 years ago changed all that. Many hospital patients now control their own pain by pressing a button on an electronic pump connected to an IV morphine drip.

But the advent of microtechnology may be improving on even that method.

In their study, funded by the manufacturer, ALZA Corporation, Viscusi and his team measured the effectiveness of the new patch, called E-TRANS fentanyl PTCS, against traditional IV PCA.

The E-TRANS device is embedded with a tiny microchip programmed to release doses of the powerful analgesic drug fentanyl into the skin whenever the patient presses a button at the top of the patch. The patch is designed to be worn on either the upper arm or the upper chest area.

As it delivers fentanyl, patients hear the device give off a "beeping signal," Viscusi explains. The patch "then tracks the number of doses by a light-emitting diode that flashes between dose sequences -- it'll flash once for one to five doses, twice for five to 10 doses, and so on," he says. The E-TRANS patch is programmed to stop when dosage levels become unsafe, and also warns the user when the drug supply is running low.

The researchers had 636 patients try out either the standard IV morphine pump method of PCA, or the new E-TRANS device, as they recovered in a hospital after surgery.

"The end result of the study was that they compared favorably to each other," Viscusi says, with nearly 74 percent of patients using E-TRANS rating their pain control as either "very good" or "excellent" and about 77 percent saying the same for the IV pump.

But E-TRANS' real advantage over the IV may come from increased patient mobility.

"If you think of being in a hospital, just getting up to go to the bathroom -- if you don't have to drag an IV pole along with you, it makes the hospital experience that much less unpleasant," Coghill says.

And Viscusi notes that E-TRANS frees nurses from having to replace morphine doses in the IV, or replacing needles if and when they become unstuck, as can often happen.

"I like to think of E-TRANS as allowing the nurse to shift their attention away from equipment and technology to more patient-focused care," he says.

According to Viscusi, no price has yet been set on the E-TRANS technology, but he believes it may end up saving health-care dollars due to reduced labor costs.

The researchers expect a decision from the FDA regarding preliminary approval of E-TRANS to come within the next month or so.

Coghill believes the patch makes patient-controlled pain relief "simply much more convenient," with most patients enrolled in the study finding the device easy to use.

There's always a psychological boost to these types of technologies, as well, Coghill says. "The pain becomes much more manageable when there's the perception that it's controlled," he explains. "By giving patients the ability to control pain, it makes it much easier to treat."

More information

For more on pain and how to control it, visit the American Society of Anesthesiologists and the American Academy of Pain Management.

SOURCES: Eugene Viscusi, M.D., director, acute pain management, Thomas Jefferson University, Philadelphia; Robert C. Coghill, Ph.D., associate professor of neurobiology and anatomy, Wake Forest University School of Medicine, Winston-Salem, N.C.; March 17, 2004, Journal of the American Medical Association

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