Infrared thermography for assessing skin temperature characteristics of postoperative blanching erythema and stage 1 pressure injuries

OBJECTIVE: To evaluate the application of infrared thermography in assessing skin temperature characteristics of postoperative blanching erythema and Stage 1 pressure injuries in patients. METHODS: An observational study design was employed. We recruited 323 patients under general anesthesia who had an expected surgical duration exceeding 3 h and who experienced intraoperative sacral pressure. Infrared thermal images of the sacral region were captured, and skin assessments were conducted before entering the operating room, after admission to the post-anesthetic care unit, and daily for 3 days postoperatively. RESULTS: A total of 12 cases of Stage 1 pressure injuries and 81 cases of blanching erythema were identified. When the temperature in the affected area was elevated compared to the surrounding normal skin, Stage 1 pressure injuries demonstrated significantly higher ΔT values than blanching erythema (p = 0.001). When the temperature was reduced, the ΔT differences between Stage 1 pressure injuries and blanching erythema were not significant (p = 0.881). However, a higher proportion of Stage 1 pressure injury areas exhibited hypothermia (50 % vs. 8.6 %). CONCLUSION: Postoperative blanching erythema and Stage 1 pressure injuries exhibit either warmer or cooler skin temperatures compared to adjacent normal skin. Compared to blanching erythema, Stage 1 pressure injuries are more likely to present with hypothermic areas or demonstrate more pronounced relative temperature increases in the affected regions.