Evidence-based injury prediction data for the water temperature and duration of exposure for clinically relevant deep dermal scald injuries.

Deep dermal burn injuries require extensive medical care; however, the water temperatures and durations of exposure that result in a severe scald injury are unknown. This study used a porcine burn model to investigate the time and temperature threshold for clinically relevant deep dermal injuries for both immersion (long duration) and spill/splash (short duration) scald events. Scald wounds were created on the flanks of anaesthetized juvenile large White pigs (27 kg). Acute tissue injury evaluations performed at 1 hour and days 1, 3, and 7 postburn (16 pigs) included: wound examination, biopsies, and laser Doppler imaging. Up to 20 burn combinations were tested including: 50-60 °C water for 1-10 minutes (immersion); and 60-90 °C water for 5 seconds (spill/splash). Burn conditions demonstrating mid-to-deep dermal damage histologically were followed for 21 days to assess time to reepithelialize (eight pigs). Histologically, depth of damage increased until day 3 postburn. Damage to ≥75% of the depth of dermis was associated with burns taking longer than 3 weeks to fully reepithelialize. For spill/splash (5 seconds) scalds, water at ≥75 °C showed damage to mid-dermis or deeper by day 3; however, only burns from water ≥85 °C were not reepithelialized by day 21. For immersion scalds of equivalent duration, water at 55 °C caused significantly deeper dermal damage than 50 °C (p < 0.05) at day 3. Immersion scalds that were not fully reepithelialized by day 21 included 50 °C for >10 minutes, 55 °C for 5 minutes, 60 °C for 60 seconds, and 70 °C for > 15 seconds. This research provides valuable evidence-based injury prediction data, which can be used to inform future burn injury prevention guidelines/legislation to reduce the risk of severe scald injuries and support medicolegal opinions for cases where an inflicted mechanism of injury is alleged.