Subepidermal Moisture and Pressure Injury in a Pediatric Population: A Prospective Observational Study

PURPOSE To describe relationships between subepidermal moisture (SEM) and visual skin assessment of pressure injury (PI) in children. DESIGN Prospective descriptive study. SUBJECTS AND SETTING Twenty-four participants aged 8 to 16 years recruited from a pediatric orthopedic unit in a children's hospital in Ireland. METHODS Subepidermal moisture measured with the SEM scanner (Bruin Biometrics, Los Angeles, California) ranged from 0 to 7 picoFarads [pF], and visual observation of trunk and heels occurred daily for 3 days after admission to the unit and/or after surgery. Skin was assessed for discoloration categorized as blanchable erythema, stage 1 PI, or deep tissue injury (DTI). Any open wound PI was classified as stage 2, 3, 4, or unstageable. Demographic, medical, and pain data were collected. Chi-square test, t tests, analysis of variance, and regression were used to describe data and examine relationships. RESULTS Participants were pediatric patients; 100% (n = 24) were white, 62% (n = 15) were female, 8 to 16 years of age (mean = 12.5 ± 2.5 years), and 29% (n = 7) had fractures and 71% (n = 17) surgery diagnoses. Blanchable erythema incidence was 21% (n = 5) and stage 1 PI incidence was 42% (n = 10); nearly all at heels. Deep tissue injury incidence was 4% (one sacral DTI). Stage 2 or greater PI incidence was 4% (one heel stage 2 PI). For skin that was assessed as normal in this pediatric population, SEM for trunk was 2.65 to 2.76 pF and for heels 2.37 to 2.41 pF. Subepidermal moisture for blanchable erythema and stage 1 PI was higher (range, 3.2-3.7 pF) and significant at trochanters and heels (left trochanter: P = .003; right trochanter: P = .02; right and left heels: P = .000). Nominal regression, controlling for participant and assessment day, showed SEM a predictor of erythema and stage 1 PI at heels. We also found that SEM was higher with pain (significant at sacrum and heels). CONCLUSIONS In this pediatric population, SEM values over skin assessed as normal are lower than SEM values reported for normal skin in adults, 2.37 to 2.76 pF. Subepidermal moisture was significantly higher for blanchable erythema and stage 1 PI at trochanters and heels, and with the presence of pain at sacrum and heels. We recommend that SEM should be examined for detecting PIs in pediatric populations; SEM and pain should be explored in larger pediatric and adult populations.