Defining Total Body Surface Area (TBSA)

Written on April 19, 2022

Burn Treatment
Burn Wounds
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One of the most common phrases you're likely to come across throughout the burn treatment process is total body surface area (TBSA). TBSA is a tool medical professionals use to assess the severity of a patient's burns. The speed and accuracy of this initial assessment is critical because it informs all steps of the patient healthcare journey, including fluid resuscitation, transfer decisions, management, prognosis, and research.

There are three primary methods of calculation. Each has its own grading system, use case, and pros and cons. In this article, we'll take a closer look at these three methods of assessing TBSA. Equip yourself with the knowledge you need to understand and ask questions about your treatment and recovery.

How Is the Total Body Surface Area Determined?

To calculate TBSA, doctors and nurse practitioners focus on three main methods: Lund and Browder, Wallace Rule of Nines, and the Palmer Method. 

Lund and Browder Chart

The first method of burn assessment uses the Lund and Browder (LB) chart. The LB chart shows both anterior and posterior diagrams of the human body and assigns percentages to each region of the body, from 1-13 percent. As medical staff members examine the burn injury, they add up the percentages of each body region to calculate the severity of all injuries. 

Lund and Browder is considered the most accurate of these three methods, but the LB chart still has its limitations. This method requires quick mental calculation. Ease of use is also a concern as medical staff members may come up with different TBSA calculations. This is why it's so important that TBSA formulas are precise, reliable, and repeatable. 

Wallace Rule of Nines

The Wallace Rule of Nines is most often used for second- and third-degree burn injuries. Every burned portion of the body is counted by a multiple of nine. Each arm, for example, is assigned 9 percent; each leg is assigned 18 percent. A doctor or nurse practitioner can quickly add up the total body surface burned based on an initial visual examination. The table below from Healthline shows the Rule of Nines percentage points for adults: 

The advantage of using the Wallace Rule of Nines is that the estimation is a simple formula, and, therefore, it is easy to calculate the amount of fluid replacement (IVs) and level of care a patient will require. It offers quick assessments in emergency situations and empowers medical professionals to quickly relay burn injury measurements to the rest of the team. Because burn injuries with a percentage of 30-plus percent can be fatal, a quick response is critical. 

Palmer Method

The third method is known as the Palmer Method. Medical staff use the length of the patient's palm (fingers together), not their own, as a reference measurement for calculating burn size and span. The length from wrist to finger = 1 percent TBSA. 

On one hand, the Palmer Method makes it easy to calculate quickly and assess a patient's fluid resuscitation and care needs. On the other hand, the Palmer Method is far from perfect science. In fact, the average adult's hand makes up 0.78 percent of their total body surface area. In most children, that same number is more than 1 percent. For this reason, the Palmer Method can lead to burn injury overestimations of anywhere from 10-20 percent. It's important to remember that the Palmer Method is only a rough initial estimate and is best used for small burns. 

TBSA Assessment Method Comparison

Methods of TBSA assessment continue to improve, thanks to 3D technology. Medical teams now have access to 3D models of human anatomy on desktop and mobile applications to quickly and accurately assess burn injuries. Full rollout and implementation is still in the works in hospitals and burn centers throughout the United States.

TBSA is just one of the first steps toward burn diagnostics, treatment, and recovery. Burn survivors can take additional steps on their own toward understanding, acceptance, and community-building as they come to terms with their injury on the road to healing. 

Phoenix Society offers a full library of resources from survivors and medical experts who understand what you're going through. Looking for added support as you navigate the treatment and recovery process? Reach out today.