Quantitative skin assessment using spatial frequency domain imaging (SFDI) in patients with or at high risk for pressure ulcers.

BACKGROUND AND OBJECTIVE: Pressure ulcers (PU) are a significant problem facing the health system in the United States. Here, we present preliminary case studies demonstrating feasibility of Spatial Frequency Domain Imaging (SFDI) to assess skin status in high-risk populations and pre-existing wounds. SFDI is a wide-field non-contact optical imaging technology that uses structured light to obtain tissue optical properties and of tissue constituents. This study aims to determine the fit of SFDI for PU care and determine the next steps. STUDY DESIGN/MATERIALS AND METHODS: Patients at risk for pressure ulcers were imaged using a near-infrared SFDI system. SFDI-derived images of tissue function (tissue hemoglobin, tissue oxygen saturation) and structure (tissue scattering) were then compared to each other as well as a blinded dermatologist's clinical impressions. RESULTS: Four case series were chosen to demonstrate the imaging capability of this technology. The first scenario demonstrates normal skin of three patients without skin breakdown with spatially uniform measures of tissue oxygen saturation, scattering, and blood volume. The second scenario demonstrates a stage II PU; the third case shows non-blanchable erythema of an unstageable PU; a fourth scenario is a clinically indistinguishable skin rash versus early stages of a PU. In all these cases, we observe spatial changes in tissue constituents (decrease in tissue oxygen saturation, increased blood pooling, decreased scattering). CONCLUSION: We have presented the first use of SFDI for pressure ulcer imaging and staging. This preliminary study demonstrates the feasibility of this optical technology to assess tissue oxygen saturation and blood volume status in a quantitative manner. With the proposed improvements in modeling and hardware, SFDI has potential to provide a means for pressure ulcer risk stratification, healing and staging. Lasers Surg. Med. 49:827-834, 2017 © 2017 Wiley Periodicals, Inc.

Development of a Nutrition Screening Tool for an Outpatient Wound Center.

OBJECTIVE: To construct a quickly and easily administered nutrition screening tool using variables believed to be predictive of malnutrition risk in the wound patient population. DESIGN: A prospective pilot study assessed patients on a list of suspected variables, as well as the Scored Patient-Generated Subjective Global Assessment (PG-SGA), chosen as the criterion standard. Variables were analyzed to select the most appropriate items for inclusion on a new nutrition screening tool using preliminary bivariate correlations and χ tests of association. Items significantly associated with malnutrition were dichotomized, and binary logistic regression analyses were performed to arrive at a final model. A sum score was computed, and receiver operating characteristic analysis was used to determine designation of risk. SETTING: An outpatient wound center in Northeast Ohio. PARTICIPANTS: The pilot study included a convenience sample of 105 outpatients with at least 1 active wound. MAIN OUTCOME MEASURES: Malnutrition as assessed by the Scored PG-SGA. MAIN RESULTS: The final nutrition screening tool, the MEAL Scale, is composed of 4 dichotomous elements: multiple wounds (number of wounds), eats less than 3 meals per day, appetite decrease (eats less than usual), and level of activity. These variables predicted 83.7% of the malnutrition cases assessed by the Scored PG-SGA. The receiver operating characteristic analysis showed an acceptable area under the curve (0.8581), and a cutoff score of 2 or greater was selected to indicate risk (median sensitivity = 91.4%, median specificity = 60.9%). CONCLUSIONS: Although further studies of validity and reliability are necessary to establish the tool before widespread use, the MEAL Scale is a needed step toward nutrition screening in a wound patient population.

Analysis of the Pressure Distribution Qualities of a Silicone Border Foam Dressing.

PURPOSE: To determine whether application of a silicone foam dressing is associated with decreased interface pressures when applied to the heel. DESIGN: Prospective, within-subjects design. SUBJECTS AND SETTING: The study was conducted in a community-based hospital using a convenience sample of 50 healthy volunteers with a mean age of 39.6 years and mean body mass index of 26.6; 70% were female. METHODS: Application of the silicone border foam dressing was randomized between the left and right heels. Participants were asked to lie down in the supine position on a viscoelastic foam mattress. Interface pressure measurements were captured using a pressure mapping system; measurements were taken once with the dressing applied to the heel (intervention map) and once without (control map). Data were captured after a 4-minute time period allowing stabilization. Analysis was based on mean interface pressure; data points were collected for both heels in each of the 2 frames, yielding 4 observations per subject. RESULTS: Application of the dressing was associated with a significant decrease in average pressure measurements as compared to the heel with no dressing applied (P < .001). Application of the dressing did not impact pressure readings for the heel to which no dressing was applied (P = .53), and application of the dressing to either the left or right heel did not impact pressure readings (ie, the random effect was insignificant; P = .9). CONCLUSIONS: Application of a silicone border foam dressing is associated with significant reduction in interface pressure and may be considered as part of a pressure ulcer prevention program.

A prospective assessment of sacral pressures in healthy volunteers seated upright and reclined with legs elevated in a recliner.

Prolonged, unrelieved pressure is a major risk factor for pressure ulceration, and interface tissue pressures have been shown to be very high when a person is sitting. Using convenience sampling methods, 23 healthy participants (four men, 19 women, mean age 45 years, body mass index [BMI] range 20-45) participated in a prospective pilot study to evaluate the effect of BMI and two commonly used seating positions in standard hospital reclining chairs on tissue (especially sacral) interface pressures. Measurements were obtained when volunteers were seated upright with plantar surfaces of feet touching the floor (Position 1) and reclining with legs resting on an elevated surface (Position 2). Measurements were obtained for 6 minutes using a thin, flexible force sensing array 430-mm x 430-mm seat mat. Average pressure, maximum pressure, and the number of sensors reading >60 mm Hg and >80 mm Hg were used for analysis across the total surface and at the sacrum. Participants were categorized by BMI (category 1: 20-22, category 2: 23-28, category 3: 29+; no participants had a BMI <20). Leg elevation reduced average pressure across the total surface (from 42.9 mm Hg to 40.0 mm Hg, P = 0.015) and the number of sensors reading >60 mm Hg at the sacrum (from 31.4 to 27.1, P = 0.047). BMI and position were significantly correlated with the number of sensors reading >80 mm Hg (P = 0.008) and average pressure (P = 0.031). Pairwise comparisons showed significant differences existed between BMI categories 1 (average delta: -3.63, indicating down position is better) and 3 (average delta: 4.67, indicating up position is better) for the difference in number of sensors above 80 mm Hg (P = 0.030). Research is needed to further explore the relationship between BMI and tissue pressure, but the results of this study suggest that for patients with a BMI >29, elevating the heels/reclining the chair significantly reduces sacral tissue interface pressure. Further research specific to pressure relief in the sitting position is needed, as neither position examined in this study was found to reduce interface pressures to generally considered safe levels for reduced-mobility patients.

Collect Data, Tell Stories: Utilizing Available Data to Improve Wound Product Selection, Reduce Costs, and Improve Outcomes.

Objective: To develop a tool to assist in the evaluation of treatment options based on clinically relevant parameters, thus enabling clinicians to heal patients more efficiently. Approach: Outlined here is the prototypic model of a comprehensive analysis tool to compare products by category, accounting for product characteristics, effectiveness data from literature, costs, and patient needs or clinician preferences. Results: The tool is demonstrated with a venous leg ulcer example, and ideas for expanding the tool in the future are provided. Innovation: Although this is a simple model, the authors believe that it provides a valid and useful platform for comparing similar products of a given type using available information and reflecting real-world use to give a practical approach to clinical decision-making. Conclusion: Future funding for comprehensive, comparative effectiveness studies should provide clarity on which products to choose for specific applications. Meanwhile, tools like this can provide guidance, and can be modified to accommodate varying circumstances.

Wound dressing absorption: a comparative study.

The purpose of this study was to compare absorption properties of a variety of wound dressing products that are available on the market. A simple, inexpensive method of evaluation was utilized so that new dressings could easily be tested and added to the data set.