Continuous sweat biomarker monitoring for early detection of sacral pressure injuries in postoperative patients: A prospective dual-zone wearable sensor study.

AIM: To evaluate whether a dual-zone wearable sweat biosensor patch could detect biochemical signatures of sacral pressure injury earlier than standard nursing assessment in postoperative patients requiring prolonged bed rest. METHODS: This prospective, observational, single-arm study enrolled postoperative patients requiring prolonged bed rest with a Braden Scale score (a validated tool for pressure ulcer risk assessment) of 18 or lower. Two flexible biosensor patches were applied simultaneously to each participant: one at the sacral pressure zone (T1) and one at a reference site (T2), continuously monitoring sweat lactate, sweat pH, and skin temperature over 72 h. Ward nurses performed daily blinded clinical skin assessments independently of sensor data. RESULTS: Fifty-three patients who developed sacral pressure injury were included. All three biomarker differentials demonstrated progressive divergence over 72 h, with statistically significant between-zone differences emerging from the 12-24 h interval. The biosensor system achieved a mean lead time of 34.1 h over nursing detection, with 77.4% of patients benefiting from advance warning of 24 h or more. CONCLUSION: Continuous dual-zone sweat biomarker monitoring detected evolving sacral pressure injury substantially earlier than conventional nursing assessment, providing a clinically meaningful intervention window in the majority of postoperative patients.