Detecting Changes in Skin Status Over the Site of a Stage 1 Pressure Ulcer Using Biophysical Sensors and Biomarkers

During a patient's hospital stay the skin can be exposed to forces from sitting or lying and attachment to different medical devices. Skin health is maintained healthy through regular movements to remove pressure from the skin surface. However, sometimes if the skin is exposed to loads for prolonged periods, it can be compromised, and red marks can appear (stage one pressure ulcer). In most cases, these changes in the skin can be recovered, through regular movement and nursing care. However, in a small number of cases, the skin damage can progress further until a wound appears. It is important to find out why this may occur, so that preventive strategies can be implemented to protect skin health. Therefore, the project focuses on evaluating changes in skin health following the development of a minor pressure ulcer (stage one).

This research proposal aims to better understand how the skin changes at the body sites compromised by stage 1 pressure ulcer, compared to healthy sites. This will be achieved via the use of measurements of skin health including physical sensors and sampling fluids and cells from the skin surface. The knowledge acquired from this study will help the understanding of how and why skin breaks down following early signs of damage. Some of the proposed sensing systems could then be used to support healthcare professionals to adopt the appropriate preventive strategies to avoid skin damage and subsequent wounds. A cohort of 50 patients will be recruited from a hospital setting, who present with a stage one pressure ulcer. Skin measurements will be taken three times to establish changes during their hospital stay. The investigators will establish if these measurements support the prediction of whether the stage one ulcer heals, remains the same, or progresses into a wound (stage two or higher pressure ulcer).

This is a case controlled longitudinal observational study on patients who have the early signs of pressure ulcers, termed stage 1. In this study, a series of non-invasive measurements will be performed to assess skin status in individuals presenting with stage 1 pressure ulcers (PU). Photographic images of the compromised skin site of participants will also be collected. Participants will be tested using a well-established protocol, which consist of visiting the patient on three different occasions during their hospital stay. The first two visits will be on consecutive days while the third skin assessment session will be carried out a day before the patient is discharged. The investigator team will ensure that the sessions, which will last approximately 15-20 minutes, avoiding any interference with patients personal or healthcare commitments.

Different measurements on the participant skin surface will be taken using probes which are designed to monitor skin health (all probes are CE marked and have been employed previously in clinical trials). The measurements will include:

1. the pH (acidity) at the skin surface
2. the amount of water which is lost through the skin
3. skin hydration

In addition, sebum (oily substance) and cells from the compromised and healthy areas of the skin using commercial tapes were collected. The aforementioned skin parameters will be taken at each visit using non-invasive, harmless wireless probes, which will be placed gently in contact with the skin for a 1-minute duration. Each probe was cleaned in-between assessments following the NHS infection control policies. Skin sebum will also be taken at each assessment from the areas of interest using sebutapes, which will be gently applied to the skin for 2 minutes before removal. These commercially available tapes have been used extensively in dermatological research. Corneocytes (outermost surface cells) will be taken only on the first visit from both the compromised and healthy sites of the skin. This will be achieved using a harmless tape stripping technique during which standard sellotapes will be applied to the skin surface and slightly pressed for 5 seconds prior to removal.

Eligibility Criteria:
Inclusion Criteria:

* Aged over 18 years old
* Individuals of all genders and ethnicities
* Individuals presenting grade 1 PU (regardless of the anatomical location of the PU)
* Individuals admitted to UHST
* Have the capacity and English proficiency to provide informed consent

Exclusion Criteria:

* Individuals with broken skin
* Patients at end of life
* Patients who cannot be repositioned due to medical reasons
* Patients in COVID-19 areas
* Allergies or sensitivity to sebutape or Sellotape
* Current active skin condition on the areas of measurement
* Cognitive impairments which limit their ability to provide informed consent
* Inability to understand English language