Delayed cooling of an acute scald contact burn injury in a porcine model: is it worthwhile?

The current Australia and New Zealand Burn Association recommended burns first aid treatment is to place the burn under cool running water for 20 minutes. Immediate cooling of a burn wound has been shown to reduce the depth of the injury. Cooling has also been recommended as beneficial for up to 3 hours after the burn. No scientific data currently exist to support this recommendation. The aim of this study was to identify the effect of delayed cooling of an acute scald contact burn wound in a porcine model. Four partial-thickness contact scald burn injuries were induced in 12 piglets each. First aid treatment consisting of cool running water for 20 minutes was instituted randomly to each wound at different time points: immediately and at time delays of 5, 20, and 60 minutes. The group receiving immediate first aid with cool running water for 20 minutes served as the control group. At day 1 and day 9, biopsies were obtained and assessed in a blinded manner. Histologic analysis of burn depth on days 1 and 9 demonstrated no significant difference in the depth of the burn in the various treatment groups in comparison to the control group receiving immediate first aid. No significant differences in the surface areas of each burn were noted between the various treatment groups on day 9. Core body temperature did not fall below 35 degrees C throughout the cooling process. This study provides scientific evidence that in an animal model delayed cooling for up to 60 minutes postacute contact scald burn is still effective compared with immediate cooling at reducing burn depth.