Pressure injury detection using alternate light: a proof-of-concept study

Identification of early-stage pressure injuries (PIs) during visual skin assessment may be subjective and unreliable. An alternate light source (ALS) has been shown to increase the probability of detecting evidence of bruises on individuals with darker skin tones. Bruises and early-stage PIs are often difficult to identify, especially in those with darker skin tones, where melanin concentration is high. Given the effect skin pigmentation has on detecting both types of cutaneous injuries, this proof-of-concept study aimed to describe the characteristics of Stage 1 PIs and deep tissue PIs as viewed under an ALS.

Eligible participants were first examined by a certified wound ostomy continence nurse using environmentally available white light. A blinded second examiner then evaluated the size of the potential tissue impairment using violet (406nm) and blue (448nm) ALS viewed through yellow and orange goggles, respectively. Portable ultrasound was used to confirm tissue involvement. Data were summarised using descriptive statistics.

The study included 10 participants (40% of whom were from minority racial/ethnic groups) with a mean Braden Scale score of 11.1. The majority of PIs (80%) involved deep tissue and were located on lower extremities (60%). The median PI size was larger by 17.5cm² and 13.7cm², respectively, using ALS compared with white light when viewed under violet and blue wavelengths. Ultrasound data were limited to non-extremity regions (n=3 participants) with hypoechoic areas noted as being 10-13mm in thickness and up to 16.7mm deep.

Evidence of tissue damage that extended beyond that visualised under white light was noted with ALS. Usefulness of ultrasound was limited over bony prominences where there was too little subcutaneous tissue. Further research is warranted to investigate the potential application of ALS for the early detection of PIs.