Dear Readers: An old adage says, “You can’t manage what you don’t measure.” Measuring wound features allows you to track progress, providing you and your patients with feedback about how well the current protocols of patient and wound care are working. This month’s Evidence Corner covers two recent articles on wound measurement. The first, for CME credit, reviews techniques for measurement of several wound or patient characteristics and illustrates how appropriate measurement can guide care. The second article focuses on measuring wound size and explores the reliability and concurrent validity of wound size measurements made by hand or assisted by a computer. Both illustrate strengths and efficiencies that wound measurement adds to clinical practice. In addition, the readers should be alerted to the section, Skin Measurement Techniques, which will be featured in the upcoming March issue of WOUNDS.
Laura Bolton, PhD
An Overview of Wound Measurement Tools
Reference: Goldman RJ, Salcido R. More than one way to measure a wound: An overview of tools and techniques. Adv Skin Wound Care 2002;15:236–45.
Rationale: Clinicians can improve their clinical practice and the quality of patient care by enhancing understanding of the tools and techniques available for wound measurement.
Objective: Advantages and disadvantages are described for various techniques of measuring wound dimensions, visual and photographic assessment methods, and vascular and pressure assessment methods.
Methods: The authors review the literature on measuring wound length, width, depth, area, volume, visual assessments, such as wound bed color, techniques for managing digital images, and photogrammetry, in which a computer evaluates wound images. Recognizing that wounds need good circulation to heal, they also describe the ankle-brachial index (ABI) as a test of arterial insufficiency, segmental volume recording, also known as pulse volume recording, and transcutaneous oximetry to clarify the nature and site of arterial insufficiency as well as point-sensors and pressure mapping to identify pressure problems.
Results: In addition to benefits and drawbacks of each measurement technique, the noninvasive circulatory results illustrate in patient scenarios how measurement assists in wound care decision making. For example, ABI is reportedly useful as a bedside procedure to exclude arterial insufficiency and determine if therapeutic compression can be safely applied. Features, benefits, and costs of wound measurement and pressure mapping tools are also compared.
Conclusions: In choosing wound measurement techniques to meet their wound care goals, clinicians and researchers balance practical issues, such as time and resources involved, against scientific issues, such as reliability and validity of the results or the constraints of practice patterns, staff knowledge and skills, certification guidelines, and cost.
Clinical perspective: Measuring wound and patient risk factors can enhance clinical wound care by giving an evidence-based edge to clinical experience, which allows clinicians to track patient and wound progress and incorporate legally defensible, objective criteria into clinical decision making. The feedback from tracking progress can motivate patients and staff and inform clinicians when protocols of care are or are not working so all can move forward to improve outcomes.
Computer-Assisted Compared to Manual Wound Size Measurement
Reference: Thawer HA, Houghton PE, Woodbury G, Keast D, Campbell K. A comparison of computer-assisted and manual wound size measurement. Ost/Wound Manag 2002;48(10):46–53.
Rationale: Accurately, precisely measuring wound size documents wound progress and effectiveness of interventions. Linear dimensions, volume measurements, planimetry, and tracings are generally reliable, but each has limitations. Single-camera computerized photogrammetry (SCP) has the potential to overcome these limitations while providing digital records for other forms of wound documentation but lacks validation and reliability testing on real wounds.
Objective: This study compared intra- and interrater reliability and validity of SCP versus manual planimetry of tracings (P) as area measurements of clinical wounds and smaller animal wounds.
Methods: Lower-extremity ulcers 0.99 to 18.80cm2 in area on 45 outpatients and full-thickness excisions 0.10 to 2.20cm2 in area on 38 CD-1 male mice were measured in area three times by two assessors in random order using either planimetry of wound tracings or SCP of the actual wound. Intraclass correlation coefficients (ICC) measured intra- and interrater reliability. ICC of single versus average of three area measurements assessed concurrent validity. Precision was measured as standard error of measurement (SEM) for each technique.
Results: Reliability, precision, and concurrent validity of both techniques were high on clinical wounds, while SCP was more reliable and precise than P on the smaller animal wounds.
Conclusions: The SCP technique is as reliable, valid, and precise as P on clinical wounds and more precise on smaller animal wounds. The decision to use a manual or computerized technique in clinical practice or research should be based on patient, practicality, and economic considerations.
Clinical Perspective: Reduction in wound area after two weeks of care is a hallmark of healing and a strong predictor of whether a pressure ulcer or leg ulcer is on the path toward healing. Consistent area measurements, whether estimated from longest length x longest width, planimetry, counting squares within tracings, or using more advanced computerized techniques, serve wound care professionals well in monitoring the effects of care and in alerting professionals to healing challenges.