What Every Nurse Should Know: Estimating TBSA

The burn unit: one place I NEVER wanted to float to in the hospital!

It was all ages at the hospital where I was. As you can imagine where all situations were difficult, some of the pediatric cases were incredibly heartbreaking.

I have a lot of respect for nurses and CNAs who care for clients with burns. It is a very difficult job to know you must inflict necessary pain on someone in order to help them to recover from a horrible injury.

Whatever department you end up in throughout your nursing career, you will want to remember the “Rule of Nine’s” for adults and "Rule of Palms" to rapidly assess the extent of burns on the skin surface. This information is used to estimate the extent of burn injury, whether transfer to a burn center is needed, and is essential for guiding care. Additional tools are used to calculate precise fluid requirements over the first 24 hours, but these 2 tools are ones to know cold for the NCLEX.

Total body surface area (TBSA):

Rule of Nine’s (adult)

•Head 9% (4.5 % anterior/4.5% posterior)

•Abdomen & chest 18%

•Back 18%

•Anterior leg, each 9%

•Posterior leg, each 9%

•Entire arm, each 9% (4.5% for anterior/4.5% for posterior) *Remember each arm is ONLY 9% if both anterior and posterior are burned! This tends to cause confusion when calculating TBSA and is a common error!

•Genitalia/perineum 1%

Rule of Palms

  • The surface area of the patient palm represents 1% of total body surface area
  • Used to estimate small or irregular burn areas