Development of a Consistent and Reproducible Porcine Scald Burn Model

Abstract

There are very few porcine burn models that replicate scald injuries similar to those encountered by children. We have developed a robust porcine burn model capable of creating reproducible scald burns for a wide range of burn conditions. The study was conducted with juvenile Large White pigs, creating replicates of burn combinations; 50°C for 1, 2, 5 and 10 minutes and 60°C, 70°C, 80°C and 90°C for 5 seconds. Visual wound examination, biopsies and Laser Doppler Imaging were performed at 1, 24 hours and at 3 and 7 days post-burn. A consistent water temperature was maintained within the scald device for long durations (49.8 ± 0.1°C when set at 50°C). The macroscopic and histologic appearance was consistent between replicates of burn conditions. For 50°C water, 10 minute duration burns showed significantly deeper tissue injury than all shorter durations at 24 hours post-burn (p ≤ 0.0001), with damage seen to increase until day 3 post-burn. For 5 second duration burns, by day 7 post-burn the 80°C and 90°C scalds had damage detected significantly deeper in the tissue than the 70°C scalds (p ≤ 0.001). A reliable and safe model of porcine scald burn injury has been successfully developed. The novel apparatus with continually refreshed water improves consistency of scald creation for long exposure times. This model allows the pathophysiology of scald burn wound creation and progression to be examined.

Skin thickness measurements increase with excision and biopsy processing procedures

“…To the Editor: For researchers and pathologists examining skin samples, comparisons between in vivo measurements and histologically determined values for skin thickness are often required. Recently, during development of a porcine burn model, 1 we observed skin thickness measured histologically was substantially thicker than in vivo ultrasound measurements. Anecdotally a generalized "shrinkage" of skin sample dimensions with formalin fixation is well accepted, with reports of decreasing thickness postprocessing for excised human skin tumors 2 and porcine and human cadaver skin.…”

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

“…The method of general anesthesia and monitoring was exactly as described by Andrews et al Briefly, anesthesia was induced with Ketamine 13 mg/kg (Ketamine 100 mg/mL; Ceva, Glenorie, NSW, Australia) and 2 mg/kg Xylazine (Ilium Xylazil 100 mg/mL; Ilium, Troy Laboratories Pty Ltd, Glendenning, NSW, Australia) and maintained with 1–2.5% Isoflurane (Attane, Bayer Australia Ltd, Pymble, NSW, Australia). Buprenorphine 0.01 mg/kg (twice daily, Temgesic 0.3 mg/mL; Reckitt Benckiser Healthcare, Slough, Berkshire, United Kingdom) and Fentanyl 50 µg/hour patches (every 3 days, Durogesic 50; Janssen‐Cilag Pty Ltd, North Ryde, NSW, Australia) were administered as needed to provide analgesia.…”

“…Circular scald wounds, approximately 16 cm 2 , were created using a purpose made scald device . Preheated water (set at a desired test temperature) was pumped into the device and vacuum suctioned out at an equivalent rate, ensuring the water temperature was constant for the required exposure time.…”

“…Burns were located on the lateral aspect of the thorax, with four burns each side, giving a total of eight burns per pig. A comprehensive description of this model including location of burns, description of the device, and temperature monitoring was previously reported by Andrews et al…”

“…Pigs are accepted as an appropriate animal model for thermal injury investigations given the physiological and anatomical similarities between human skin and pig skin . For this study, a previously developed porcine scald model was used. The primary aim of this study was to establish the burn conditions (water temperature and duration of exposure) to cause clinically relevant severe spill/splash or immersion scald injuries.…”