Fast, easy and painless wound assessment tool is a gamechanger
A new, hand-held device allows doctors at the
Cape Cod Healthcare Wound Care Center in Bourne and Hyannis to assess patient’s wounds pain-free. The new technology allows physicians to quickly assess tissue oxygenation and healing potential without touching the wound.
“Near-infrared spectroscopy can be done right at the bedside,” said
Patrick J. Flynn, MD, PCWC, FAPWCA medical director of the Wound Care Center. “It’s not invasive. No dyes or medication. All done with a handheld camera that gives results in seconds.”
As a result, patients may not need to be subjected to other testing methods that may take longer or must be done at another facility, he said.
The device creates color coded images corresponding to the amount of oxygen-rich blood in the wound and surrounding tissues.
“You can show results to the patient right at bedside,” said Dr. Flynn, a surgeon who’s board-certified in Wound Care. “It’s very easy for even the patient to see what looks healthy with good blood flow and what does not.”
Other advantages of the device, according to Dr. Flynn, include:
No disposable parts that have to be replaced;
No need to sterilize;
Readily reproduceable results; and
Ease of use.
Faster, Easier, Less Intrusive
Wounds require adequate blood flow to heal. Blood brings needed oxygen and nutrients to the tissue, and traditional methods of assessing blood flow may fall short when evaluating skin perfusion, according to a
2018 article in the journal Clinics in Podiatric Medical Surgery. A patient may possess good blood flow in general, but still have poor perfusion to the skin.
One of these traditional methods is called the ankle-brachial index, which compares blood pressure readings taken from a patient’s arm and leg. Many of the patients at the Wound Care Center have wounds on their legs and feet, often the result of poor circulation caused by peripheral artery disease or diabetes, according to Dr. Flynn.
“We still do them,” he said of the ankle-brachial index. “It’s still the standard screening test. In most people, it’s a pretty good test. In diabetics in particular, it can, however, be falsely elevated.”
Blood vessels in people with diabetes can become calcified and stiff, so they don’t respond the same as normal vessels to the compression of a blood pressure cuff, he said. One way around this problem in evaluating blood pressure in the foot is by using a small cuff that fits around the great toe to generate a toe-brachial index.
“Calcification of the vessels seems to spare the digits,” Dr. Flynn said. “The downside is we have to send the patient off to the vascular lab” for the toe-brachial index test to be done, thus creating a delay in getting important information.
A second method to evaluate blood flow uses ultrasound to directly visualize flow in the blood vessels. Called arterial duplex ultrasound, it provides good results but also needs to be done in a vascular lab, Dr. Flynn said.
A third method,
transcutaneous oximetry, measures oxygenation at the edges of a wound through electrodes positioned on the skin, according to the National Library of Medicine.
“The problem with that test is it took often 45 minutes to do and results were often inconsistent,” Dr. Flynn said.
Uses at the Wound Care Center
Other advantages of near-infrared spectroscopy are that it can be used when a patient is first seen, and repeated during follow-up visits, to gauge any changes in perfusion; particularly if the patient has had a procedure to improve blood flow, Dr. Flynn said.
The device can also help guide removal of tissue that’s dead or lacks good perfusion, a process called wound debridement. With near-infrared spectroscopy, doctors can “make sure perfusion is sufficient before deciding to debride a wound.” The device can also help guide adequacy of debridement by taking images before and after debridement.
High levels of oxygenated blood in tissue correspond to healthy blood flow but can also mean the presence of infection or inflammation, Dr. Flynn said. Inflammation causes the healing process to stall, he went on to explain.
“Wounds that aren’t healing are stuck in the inflammatory phase of wound healing,” he said. “The device can provide clues that there is ongoing inflammation.”
The technology behind near-infrared spectroscopy has existed for several years, but its use in assessing wounds is still growing in acceptance, Dr. Flynn said.
“We’ve had it, I want to say, three to four years,” he said. “We’re one of the first centers in the country to adopt it. It’s becoming more and more popular. I wouldn’t say it’s mainstream yet, but more and more Centers are using this technology.”