Assessing the extent of a burn

To guide management goals, it is important to assess both extent and depth of the burn.

To assess the extent of a burn it is vital to expose all areas of the body to accurately estimate percentage TBSA affected. This is essential to:

• Decide whether the patient requires fluid resuscitation (>10% TBSA in children or >15% TBSA in adults)
• Calculate the fluid requirement during the initial resuscitation period if needed

Common ways to estimate %TBSA are

• Lund and Browder charts (fig 12a)
• Using the patient’s palm (including finger and thumb surfaces) as an estimate of 1% TBSA
• Rule of 9s (fig 12b)
• Mersey Burns App (fig 12c) which enables the user to highlight areas of burn tissue on a model to accurately estimate %TBSA affected

adapted from: https://rphcm.allette.com.au/publication/cpm/Burns.html

Ref: Modified from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC449823/

**Link to app store Mersey burns app store**

Not all of the burn area would necessarily be included in the %TBSA calculation. The depth of burn needs to be considered.

Top tip:

• Epidermal burns are not included when calculating the burn %TBSA