diffuse-reflectance-spectroscopy-getting-capillary-refill-test-under

Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb

The capillary refill test was introduced in 1947 to help estimate circulatory status in critically ill patients. Guidelines commonly state that refill ...

linköping university

Region Östergötland

Microdialysis is a minimally invasive technique for chronological study of metabolic, biochemical, and pharmacological events in living tissue. In the skin, probes are placed in the dermis or subcutis for research in two main areas, percutaneous penetration and various aspects of inflammation. Advances in technique, and the concept of data generation and analysis are leading to new areas of application.

Cutaneous microdialysis: is it worth the sweat?

Skin tags (acrochordons) are exceedingly common benign skin lesions. A novel medical device in the form of a flat adhesive patch applies pressure to the base of a skin tag, leading to its removal within 3-6 days. The device was used in a clinical trial to treat and remove skin tags of the neck, upper torso, and axillae in volunteers. In this study, a total of 177 skin tags were treated in 32 individuals. One hundred seventy-two lesions fulfilled intention to treat (ITT) criteria. A majority of ITT lesions (90%) reached final assessment. Successful outcome was highest (90%) for lesions up to 1 mm in base. For lesions up to 2 mm, the rate of successful outcome was 76 percent. The desired outcome was seen in 65 percent of all ITT lesions. The cosmetic outcome after removal was excellent. Discomfort was assessed as minimal during all stages of the procedure. Analysis of data on blood flow in the skin tags during the treatment showed that the outcome was influenced by whether a decrease in blood flow was achieved immediately after application and at 2-3 days, but that the degree of occlusion was not critical. The results of this study illustrate that the device presents a new option for the management of unmet needs in the treatment of skin tags.

New mechanical device for effective removal of skin tags in routine health care.

The colour of tissue is often of clinical use in the diagnosis of tissue homeostasis and physiological responses to various stimuli. Determining tissue colour changes and borders, however, often poses an intricate problem and visual examination, constituting clinical praxis, does not allow them to be objectively characterized or quantified. Demands for increased inter- and intra-observer reproducibility have been incentives for the introduction of objective methods and techniques for tissue colour (e.g. erythema) evaluation. The aim of the present paper was to study the border zone of a UVB-provoked erythematous response of human skin in terms of blood volume and oxygenation measured by means of diffuse reflectance spectroscopy using a commercial probe.

A diffuse reflectance spectroscopic study of UV-induced erythematous reaction across well-defined borders in human skin.

Insertion of a cutaneous microdialysis catheter into normal dermis has been shown to induce the production of IL1b, IL6 and IL8 in an innate response to minimal trauma. In the present study, skin biopsy for immunohistochemistry has been performed at the site of the microdialysis catheter to compare the findings with that of the microdialysis findings 24 h after insertion. Of the three named cytokines, concordance between the two investigated technologies was highest for IL8 (100%) followed by IL6 (70%) and IL1b (50%). For seven other pro-inflammatory and T cell-relevant cytokines studied, concordance ranged between 50% and 80%. The total number of positive (microdialysis or immunofluorescence) findings was similar between the two methodologies. Technical and biological phenomenon can explain the differences. We conclude that both methodologies illustrate important features of tissue biology and that a combination of the two methods in clinical research can provide the chronology of soluble mediator participation and the more classic, but also more invasive, biopsy-based methodology at a point which constitutes the end of the observation period. We conclude further that at the 24-h time period here studied, microdialysis catheters are still functional and thus capable of producing relevant data which can be corroborated and extended by the "end point biopsy".

Are cutaneous microdialysis cytokine findings supported by end point biopsy immunohistochemistry findings?

Cutaneous microdialysis demonstrates cytokine production in living human skin. In the present study, microdialysis samples taken from uninvolved and lesional skin in three test subjects with psoriasis over 24 h have been investigated for cytokine content with a bead-based multiplex immunoassay from Luminex. Concentration curves for a set of Th1/Th2 and pro-inflammatory cytokines measured differed from a reference group of ten subjects without psoriasis. The time to return to near baseline values after innate insertion reactivity is between 9 and 16 h. Post-equilibration levels (17-24 h) for the three main cytokines elevated in the reference group were differentially elevated outside the range of the reference group for interleukin-1β (IL1β) and IL8 but not so for IL6. Two further cytokines, granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-α not generally elevated in the reference group, showed elevated values in the test subjects. Multivariate time series analysis (chemometry) showed that cytokine patterns for the individual test subjects often fell outside the 99% confidence intervals of a model generated from the reference group. In a clinical research situation, cutaneous microdialysis is feasible, gives generally higher cytokine levels than in the blood and generates interpretable data on an individual's reactivity compared with a reference group. This may well prove useful in delineation of pathogenetic issues, selection of appropriate therapy and monitoring of subsequent response in inflammatory dermatoses such as psoriasis.

Cutaneous microdialysis: cytokine evidence for altered innate reactivity in the skin of psoriasis patients?

Gene expression profiling of macrophages: implications for an immunosuppressive effect of dissolucytotic gold ions.

In both Sweden and Australia high incidence rates of skin cancer have become a major health problem. In prevention and risk communication, it is important to have reliable ways for identifying people with risky sun habits. In this study the validity and reliability of the questionnaire Sun Exposure Protection Index (SEPI), developed to assess individual's sun habits and their propensity to increase sun protection during routine, often brief, clinical encounters, has been evaluated. The aim of our study was to evaluate validity and reliability of the proposed SEPI scoring instrument, in two countries with markedly different ultraviolet radiation environments (Sweden and Australia).

Validation of sun exposure and protection index (SEPI) for estimation of sun habits.

To use Bioengineering methodology is used to achieve, at five anatomical sites, a detailed, quantitative assessment of the return of blood content to the blanched area, during the Capillary Refill (CR) test. An observational, non-randomized, experimental study on 23 healthy subjects (14 females) was performed in our climate controlled skin physiology laboratory. Our main outcome measures were based on the chronological assessment and quantification of red blood cell concentration (RBC) after the release of blanching pressure in the CR test, using Tissue Viability Imaging (TiVi), a digital photographic technique based on polarisation spectroscopy. TiVi enabled collection of detailed data on skin RBC concentration during the CR test. The results were shown as curves with skin blood concentration (TiVi-value) on the y-axis and the time on the x-axis. Quantitative CR responses showed site and temperature variability. We also suggest possible objective endpoint values from the capillary refill curve. Detailed data on skin RBC concentration during the CR test is easily obtained and allows objective determination of end points not possible to achieve by naked eye assessment. These findings have the potential to place the utility of the CR test in a clinical setting in a new light. Picture: Regular photograph and TiVi Image showing CR test and corresponding graph for the CR response.

Article	Year
Cutaneous microdialysis: is it worth the sweat? The Journal of investigative dermatology\| PubMed ID: 16702967	2006
New mechanical device for effective removal of skin tags in routine health care. Dermatology online journal\| PubMed ID: 19336026	2009
A diffuse reflectance spectroscopic study of UV-induced erythematous reaction across well-defined borders in human skin. Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging (ISSI)\| PubMed ID: 20636996	2010
Are cutaneous microdialysis cytokine findings supported by end point biopsy immunohistochemistry findings? The AAPS journal\| PubMed ID: 20967522	2010
Cutaneous microdialysis: cytokine evidence for altered innate reactivity in the skin of psoriasis patients? The AAPS journal\| PubMed ID: 22374383	2012
Gene expression profiling of macrophages: implications for an immunosuppressive effect of dissolucytotic gold ions. Journal of inflammation (London, England)\| PubMed ID: 23140489	2012
Validation of sun exposure and protection index (SEPI) for estimation of sun habits. Cancer epidemiology\| PubMed ID: 26547793	2015
Reflectance spectroscopy: to shed new light on the capillary refill test. Journal of biophotonics\| PubMed ID: 28544641	2017
Microdialysis in Profiling Cytokines and Other Macromolecules in the Skin in Health and Disease: A Comment to Falcone et al. Acta dermato-venereologica\| PubMed ID: 28933512	2017

Chris D. Anderson

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