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

Abstract

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.

Keywords: Early detection; Pressure injury; Risk assessment; Subepidermal moisture.