Rule of Nines for Burns in an Adult NCLEX Review

This NCLEX review will discuss the Rule of Nines for burns in an adult patient.

If you’re studying burns right now in class, you can probably count on a rule of nines burn question being on your exam. It’s a popular topic to cover on a burns exam.

Lecture on Rule of Nines

What is the Rule of Nines?

It’s a quick calculation that can be used to calculate the total body surface area (TBSA) percentage that is burned on a patient. It is used for burns that are at least partial-thickness or greater.

• Why do we need to know the total body surface area percentage burned on a patient?

It tells us the severity of the burn. For example, does this patient need specialized care and meet the criteria for a burn unit? Another reason, which is a BIG one, this percentage will determine the fluid replacement treatment regime.

When a patient experiences about 15% or more of a total body surface area that is burned there is a major change in capillary permeability and the patient most definitely needs fluid replacement (Diver, 2008).

• What happens during a severe burn to the capillary permeability?

When a patient experiences a major burn, there is a shift of fluid from the intravascular area to the interstitial tissues (so fluid leaves the blood), and this is due to an increase in capillary permeability. Because of this shift there will be barely anything left in the circulation for the heart to pump to vital organs…without blood they start to die. So, a patient is at risk for hypovolemic shock when they experience severe burns.

Lactated Ringer’s (an isotonic solution) is most commonly used to help expand the intravascular compartment. To determine how much fluid a patient will need 24 hours after a severe burn, the Parkland Burn Formula is used (please see the next review for how to calculate the amount of fluid a patient needs after a severe burn).

Rule of Nines for Burns

Now, let’s look at the Rule of Nines!

Each area of the body is broken down by nines (hence makes it easier to remember). I like to start my way from the top and work downward:

NOTE: Remember that there is a FRONT AND BACK percentage value assigned to EACH AREA (many people forget this and get their calculation wrong).

Adult:

Head and Neck: 9% (4.5% anterior and posterior)

Right Arm: 9% (4.5% anterior and posterior)

Left Arm: 9% (4.5% anterior and posterior)

Trunk: 36% (18% anterior and posterior)

Perineum: 1%

Right Leg: 18% (9% anterior and posterior)

Left Leg: 18% (9% anterior and posterior)

Total: 100%

Rule of Nines Practice Problem:

A 35 year old female patient has deep partial-thickness burns on the front and back of both arms, anterior trunk, back of left leg, anterior and posterior sides of the right leg, posterior head and neck, and perineum. What is the total body surface area percentage that is burned?

FRONT and BACK of both arms: 18%

ANTERIOR trunk: 18%

BACK of left leg: 9%

ANTERIOR and POSTERIOR of right leg: 18%

POSTERIOR head and neck: 4.5%

Perineum: 1%

Total: 68.5%

More Rule of Nines Practice Problems

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