From the Guidelines
The degree of burns is calculated using the "Rule of Nines," which divides the body into sections each representing 9% (or multiples of 9%) of total body surface area. Burns are classified into three degrees based on the depth of tissue damage.
- First-degree burns affect only the outer layer of skin (epidermis), causing redness, pain, and minor swelling but no blisters.
- Second-degree burns damage both the epidermis and part of the dermis beneath, resulting in blisters, severe pain, and a glossy appearance.
- Third-degree burns destroy all layers of skin and potentially underlying tissues, appearing white, charred, or leathery with reduced pain sensation due to nerve damage. The extent of burns is calculated using the "Rule of Nines," which divides the body into sections each representing 9% (or multiples of 9%) of total body surface area:
- each arm is 9%,
- each leg is 18%,
- the front torso is 18%,
- the back torso is 18%,
- the head is 9%,
- and the genital area is 1%. For children, the percentages differ slightly with the head representing a larger proportion. This calculation helps determine treatment approaches, including fluid resuscitation needs, which is especially critical for burns covering more than 15-20% of body surface area, as noted in general medical practice, although not directly mentioned in 1.
From the Research
Calculation of Burn Degree
The degree of burns can be calculated using various methods, including:
- The "Rule of Nines" 2, 3
- The Lund-Browder Chart 2, 3, 4
- The "Rule of Palm" 2
- Computer-based evaluation methods 2, 4
- The Resuscitation Burn Card (RBC) 3
Methods of Calculation
These methods estimate the total body surface area (TBSA) affected by the burn, which is crucial for assessing the severity of the burn and determining the appropriate treatment. The TBSA can be calculated using the following formulas:
- The Parkland formula, which is printed on the Resuscitation Burn Card (RBC) 3
- A formula to calculate pediatric burn fluid requirements, also printed on the RBC 3
Accuracy of Calculation Methods
Studies have shown that there can be significant deviations in burn size estimates among clinicians, with overestimation of up to 161% compared to computer-based methods 2. The use of improved methods for burn depth/size assessment, such as computer-based evaluation methods, can help to efficiently allocate and distribute resources for burn care 2.
Tools for Calculation
Various tools are available to aid in the calculation of burn degree, including: