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Assessing non-healing ulcers

• Measurement (length, width, depth, area),
• Exudate (amount, quality),
• Appearance (wound bed appearance, tissue type and amount),
• Suffering (patient pain level using validated pain scale),
• Undermining (presence or absence),
• Re-evaluate (monitor all parameters on regular basis
every one to four weeks), and
• Edge (condition of wound edge and surrounding skin).

A team led by David H. Keast, MD, outlined a new technique in assessing non-healing ulcers in a poster presentation at the annual meeting of the Canadian Association of Wound Care. Dr. Keast is clinical adjunct professor of family medicine, University of Western Ontario, London.

The efficacy of wound surface area measurement techniques was compared. The ruler method can calculate the rectangular and elliptical areas of the wound. However, the rectangular measurement overestimates wound size a mean 44 per cent, and the elliptical measurement overestimates wound size a mean 13 per cent. It is more accurate for smaller wounds and progressively less accurate for larger wounds.

The acetate tracing method uses a grid system to determine how many square centimetres the wound surface is. While this is more accurate than the ruler method and a permanent record is generated, estimating the size of partial squares presents a problem.

Acetate tracing with mechanical planimetry is reliable and accurate and provides a permanent record, according to Dr. Keast and colleagues. However, it requires more skill and is more expensive to use. It is most often used for studies.
Digital photography with computerized planimetry is reliable and accurate and provides a digital record, but it is expensive and not available at the bedside.

Acetate tracing with a digitizing tablet (VisiTrak™) is reliable and accurate and provides a permanent record. It can also be used at the bedside, gives a percentage change of true surface area, and calculates percentage of necrotic tissue.

Measuring the depth of the wound is usually done by inserting a sterile probe into the deepest part of the wound, marking the level of the skin with the thumb, and measuring the distance between the tip of the probe and the thumb with a ruler. The authors noted that this technique has a 15 per cent variability and that changing depth may be initially more predictive of healing rates in deeper ulcers.

Exudate tells whether or not the wound is serous, sanguinous, purulent, serosanguinous, or serupurulent.

“Appearance evaluates the percentage of the wound bed that is covered by granulation tissue, slough, fibrin, or eschar,” Dr. Keast told Dermatology Times of Canada.

Suffering is determined by a detailed patient history. This may indicate whether the pain is related to the treatment or whether the wound is becoming more infected. Patient history should include the nature, duration, onset, exacerbation, and relief of pain.

Undermining is mapped with a sterile probe and drawn on the skin. Undermining is recorded at four quadrants (eg, 20cm at 6 o’clock).

Re-evaluate the wound and document the findings every one to four weeks, Dr. Keast and colleagues said. If the wounds are assessed too often, treatments may be inappropriately changed. “However, re-evaluations that are infrequent may miss significant changes,” he said.

Edge describes the condition of the wound and surrounding skin. Descriptions include attached with advancing border of epithelium, indurated and/or inflamed, and macerated.