RULE OF NINE
The rule of nine is a tool used for the rough estimation of the total body surface area (TBSA) affected by a burn.
- This is useful in directing treatment solution including estimating patients’ fluid requirements and determining hospital admission criteria.
- The rule of nine can be performed quickly and easily and can help in the initial management of burn patient.
- The rule of nine is useful when evaluating larger burn areas.
- This rule of nine is only applied to second degree and third-degree burns,
- The rule of nine was published by AB Wallace in 1951 but was devised by Pulaski and Tennison in 1947.
- Little modification is done in children as they have a larger head and smaller mass in the legs and thighs.
- To account for this difference, a rule of nine for children was proposed
Using this approach, the whole body part has been assigned BSA values.
IN ADULTS
BODY PART ESTIMATED BODY SURFACE AREA (BSA)
Entire left arm 9%
Entire right arm 9%
Entire head 9%
Entire chest 9%
Entire Abdomen 9%
Entire back 18%
Entire right leg 18%
Entire left leg 18%
Groin 1%
IN CHILDREN
BODY PART ESTIMATED BODY SURFACE AREA (BSA)
Entire left arm 9%
Entire right arm 9%
Entire head 18%
Entire chest 9%
Entire Abdomen 9%
Entire back 18%
Entire right leg 13.5%
Entire left leg 13.5%
Groin 1%
This allows an emergency provider to get a quick estimate of how much body surface area is involved in burns. For example, if a patient’s entire left leg (18%) and right leg 18%) is burned, this means that about 36% of the patient’s body surface area is affected. The body surface area assigned to each body part refers to the entire body part, for example, if half of a patient’s back were burned, it would be assigned a BSA value of 9% i.e. half the total body surface area of the back. So, if the patient’s entire left leg (18%) was burned, but only half of their back (9%) was burned, the BSA affected would be 27%.