To evaluate the longitudinal changes observed over a period of 120 minutes in patterns of tissue perfusion, peripheral oxygenation and local temperature of sacral and trochanteric areas exposed to pressure, comparing a healthy population with one at risk of impaired skin integrity. The study protocol is registered in ClinicalTrials.gov (NCT02736838). Non-randomised experimental study in two phases. Volunteers were recruited at the University and nursing homes from Nov 2017 to June 2020. The parameters were measured in the sacral and trochanteric areas under pressure using a laser Doppler monitor and near-infrared spectroscopy over 2 hours. Body positions varied by area: supine for the sacral region and lateral supine for the trochanteric region. Comparative analysis between both groups of the sacral area showed significant fluctuations in perfusion (p= .035) and local temperature (p= .013). In the trochanteric area, the comparative analysis showed significant fluctuations in perfusion (p= .044), local temperature (p> .001), and oxygenation (p= .049). Nonlinear patterns were identified in the variables examined in both anatomical areas. This prompted the adoption of an algorithm based on the Random Forest Regressor technique to predict the parameters associated with the development of pressure injuries. Individuals at risk of developing pressure injuries show a more limited compensatory physiological response compared to healthy individuals in terms of blood flow, oxygenation, and tissue temperature in pressure areas. Notably, at the 90-minute, a turning point is observed, marking a critical threshold from which these parameters begin to decline. • Institutionalised patients show limited microvascular compensatory response. • A 90-minute threshold marks decline in perfusion, oxygenation, and temperature. • Simultaneous monitoring reveals non-linear tissue response under pressure. • Random Forest model accurately predicts risk parameters for pressure injuries.
Inmaculada et al. (Sun,) studied this question.