Anatomical variability of sub-epidermal moisture and its clinical implications

Decreasing Intraoperative Skin Damage in Prone-Position Surgeries

OBJECTIVE

To determine if subepidermal moisture (SEM) measures help detect and prevent intraoperative acquired pressure injuries (IAPIs) for prone-position surgery.

METHODS

In this clinical trial of patients (n = 39 preintervention, n = 48 intervention, 100 historical control) undergoing prone-position surgery, researchers examined the use of multidimensionally flexible silicone foam (MFSF) dressings applied preoperatively to patients' face, chest, and iliac crests. Visual skin assessments and SEM measures were obtained preoperatively, postoperatively, and daily for up to 5 days or until discharge. Electronic health record review included demographic, medical, and surgery data.

RESULTS

Of the 187 total participants, 76 (41%) were women. Participants' mean age was 61.0 ± 15.0 years, and 9.6% were Hispanic (n = 18), 9.6% were Asian (n = 18), 6.9% were Black or African American (n = 13), and 73.8% were White (n = 138). Participants had a mean Scott-Triggers IAPI risk score of 1.5 ± 1.1. Among those with no erythema preoperatively, fewer intervention participants exhibited postoperative erythema on their face and chest than did preintervention participants. Further, fewer intervention participants had SEM-defined IAPIs at all locations in comparison with preintervention participants. The MFSF dressings overcame IAPI risk factors of surgery length, skin tone, and body mass index with fewer IAPIs in intervention participants.

CONCLUSIONS

Patients undergoing prone-position surgeries developed fewer IAPIs, and SEM measures indicated no damage when MFSF dressings were applied to sites preoperatively. The SEM measures detected more damage than visual assessment.

The effect of prolonged 60° head of bed elevation on sacral subepidermal oedema in healthy adults: A quantitative prospective exploratory study

Head of bed elevation is used to manage some medical and surgical conditions however this may increase a patient's risk of sacral pressure injuries. Novel point-of-care technologies that measure subepidermal moisture can identify changes in localised subepidermal oedema and potential pressure injury risk. This prospective exploratory study investigated variations in sacral subepidermal oedema in healthy adults during 120-min of 60° head of bed elevation. Sacral subepidermal oedema was measured at 20-min intervals using the Provisio® subepidermal moisture scanner. Descriptive analysis, one-way repeated measures analysis of variance and an independent t-test were conducted. Slightly more male volunteers (n = 11; 55%) were recruited and the sample mean age was 39.3 years (SD 14.7) with an average body mass index of 25.8 (SD 4.3). Little variation in the mean sacral subepidermal moisture of healthy adults was observed. There was a statistically significant difference in the mean sacral subepidermal moisture measurements between males and females (Mean difference 0.18; 95% confidence intervals: 0.02 to 0.35; P = .03). Healthy adults can tolerate prolonged 60° head of bed elevation without developing increased subepidermal sacral oedema. This warrants further investigation in other populations, in various positions and over different time periods.

The Effects of Incontinence Pad Application on Loaded Skin With Reference to Biophysical and Biochemical Parameters: An Exploratory Cohort Study Using a Repeated-Measures Design

PURPOSE

The purpose of this study was to evaluate temporal changes in skin responses following exposure to moisture alone or moisture in combination with mechanical loading.

DESIGN

Comparison cohort with a repeated-measures design.

SUBJECTS AND SETTINGS

The sample comprised 12 healthy volunteers. Participants were purposely sampled from 2 different age groups; half were 32 to 39 years old and half were 50 to 62 years old. Participants identified as White, Black, or mixed; 83% (n = 10) identified as White; 8 (67%) were female.

METHODS

Four sites at the sacrum were challenged with the application of specimens taken from 2 absorbent products; the pad specimens were applied dry or saturated with synthetic urine (SU; pH = 8); a further site from the sacral skin was also selected and used as a control. Skin assessments were performed at different points in time: (1) 60 minutes after exposure to dry or SU-saturated pad specimens; (2) 60 minutes after exposure to pads and mechanical loading (application of pressure in the form of 45°C high sitting); and (3) 30 minutes after removal of all pads (recovery period). Outcome measures were transepidermal water loss (TEWL), stratum corneum (SC) hydration, erythema, pH, and skin inflammatory biomarkers measured at each of the time points described earlier.

RESULTS

The control site and those exposed to dry pads showed minimal time-dependent changes irrespective of the parameter investigated. In contrast, significant increases in TEWL (P = .0000007) and SC hydration responses (P = .0000007) were detected at the sites under absorbent pad specimens after saturation with SU (exposure to moisture). In some participants, TEWL and SC hydration parameters were significantly higher during pressure application. Skin pH remained in the mildly acidic range throughout the test session, and no consistent trends were observed with erythema. Skin inflammatory biomarkers also exhibited considerable variability across participants; none changed significantly over time. Significant differences (P = .02) were also detected following the exposure of moisture in combination with pressure.

CONCLUSION

We evaluated an array of parameters to identify changes following skin exposure to 2 absorbent pads in the presence and absence of SU and mechanical loading. Analysis revealed changes in skin barrier properties in the presence of moisture and/or pressure. This observation suggests a need for frequent pad changing as well as periods of skin off-loading to protect the skin health of individuals with incontinence.

The effect of head of bed elevation on sacral and heel subepidermal moisture in healthy adults: A randomised crossover study

BACKGROUND

Subepidermal moisture (SEM) changes may detect early tissue injury and enhance pressure injury risk assessments. However, little is known how modifiable factors, like head of bed elevation (HOBE), affect SEM.

AIM

This study investigated the influence of HOBE on sacral and heel SEM, using the Provizio ® SEM Scanner.

METHOD

A 2 × 2 randomised crossover study compared the effects of 30-min of 30⁰ versus 60⁰ HOBE on sacral and heel SEM in healthy adults.

RESULTS

48 participants were randomly allocated to 30⁰ or 60⁰ HOBE and crossed over after a 60-min washout period. The mean age was 40.6 years (SD = 18.3). The study found the sacral and heel SEM values were not statistically different at 30⁰ versus 60⁰ HOBE. No clinically relevant association between SEM and characteristics of age, sex, body mass index and skin type were found. Baseline sacral and heel SEM values recovered after a 60-min washout period. Notably, half of the initial baseline measures suggested pressure injury risk.

CONCLUSION

The HOBE may not influence SEM at the sacrum and heels, in healthy adults after 30 min of loading. Standard operating procedures for measuring SEM for pressure injury risk assessment require a stronger body of evidence in varied populations and timeframes before this technology is widely adopted.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ACTRN12622001456741.

Variations in sacral oedema levels over continuous 60-degree head of bed elevation positioning in healthy adults: An observational study

BACKGROUND

Subepidermal moisture (SEM) scanning is a novel technology that measures changes in localised oedema. Accumulation of subepidermal oedema is associated with early tissue damage that may lead to a pressure injury.

AIM

The primary study objective was to observe the variations in sacral subepidermal oedema levels over a continuous period of 60-degree head of bed elevation positioning.

METHODS

Healthy adult participants were recruited in this prospective observational study. Participants were positioned at 60-degree head of bed elevation for 120 min and sacral SEM measurements were collected at baseline and in 20 min increments.

RESULTS

A total of 20 participants with a mean age of 39.3 years (SD = 14.7) were recruited. The mean SEM delta value increased 6.3% from 0.46 SEM delta at baseline to 0.49 SEM delta after 120 min, however these differences are not statistically significant (p = .21). There were also no significant findings between SEM delta variations and demographic factors.

CONCLUSION

In a sample of healthy individuals, 120 min of continuous loading with a 60-degree head of bed elevation did not lead to a significant change in sacral subepidermal oedema levels. Further research on the response of healthy adult tissue under external forces associated with different angles of head of bed positioning may further contribute to our understanding pressure injury prevention.

The effect of sub-epidermal moisture on pressure injury prevention strategies and incidence of pressure injuries: A feasibility pilot randomised controlled trial

AIM

Sub-epidermal moisture scanning (SEMS) is a novel point-of-care technology that measures localised oedema and detects early tissue damage that may develop into a pressure injury (PI). It provides objective data that may assist PI prevention (PIP) decision making. This study aimed to determine the feasibility of undertaking a definitive randomised controlled trial (RCT) to test the effectiveness of SEMS.

MATERIALS AND METHODS

This pilot RCT recruited medical and surgical patients at risk of developing a PI in one Australian hospital. All participants received routine PIP care and daily visual skin assessment to determine the presence of a PI. The intervention group also received daily SEMS. Clinical staff were told if the sub-epidermal moisture (SEM) value was abnormal but were not given advice for PIP. Blinding of patients, care staff and outcome assessors was not practical. Feasibility outcomes included recruitment, retention, intervention fidelity, and patient outcomes.

RESULTS

Of 1185 patients screened prior to eligibility, 950 were excluded (80%); 235 were then assessed for eligibility and 160 met the inclusion criteria (68.1%); 100 were recruited (70.0%) and randomised and 99 completed the trial (intervention n = 50; control n = 49) with one person withdrawn due to inappropriate recruitment (100% retention). Of the 657 expected SEMS observations, 598 were completed (91% intervention fidelity). Only 34 of 454 (7.4%) patient outcome data points were missing.

CONCLUSIONS

Most feasibility criteria were met, indicating a definitive trial to assess the effectiveness of SEMS in a medical-surgical patient population is realistic. However, recruitment may be resource intensive and require specific strategies.

Sub-epidermal moisture assessment as an adjunct to visual assessment in the reduction of pressure ulcer incidence

OBJECTIVE

To assess the effectiveness of sub-epidermal moisture (SEM) assessment technology as an adjunct to visual assessment to reduce pressure ulcer (PU) incidence alongside standard PU care pathways.

METHOD

Data were obtained from wards located within 28 institutions in the UK, Canada, Belgium, Spain and Ireland. At each ward, the proportion of patients scanned who were observed to have one or more PUs of Category 2 or above during a pre-Pressure Ulcer Reduction Programme (PURP) implementation period starting between November 2017 and July 2018 was recorded. The proportion of patients scanned who were observed to have one or more PUs of Category 2 or above during a post-PURP implementation period starting between November 2018 and July 2019 was also recorded. A meta-analysis was conducted on the data using wards as the unit of analysis, to facilitate overall estimate of the PURP. A sensitivity study was also conducted to assess the sensitivity of results to data from specific institutions.

RESULTS

A synthesised estimate of the overall relative risk (RR) was calculated to be 0.38 (95% confidence interval 0.26 to 0.56). Hence the risk of PU in the post-PURP cohort was about one-third that of the corresponding risk in the pre-PURP cohort. The sensitivity analysis revealed no evidence that any individual ward exerted excessive influence on the findings.

CONCLUSION

The analysis has revealed strong evidence that implementation of the PURP was associated with reduction in incidence of Category 2 or above PUs across a wide range of clinical settings.