Livingston E H, Lee S
VAMC Greater Los Angeles Health Care System, Los Angeles, California 90099-5786, USA.
J Surg Res. 2000 Jun 15;91(2):106-10. doi: 10.1006/jsre.2000.5909.
The measurement of burn surface area is important during the initial management of burn patients for estimating fluid requirements and determining hospital admission criteria. The "rule of nines" is commonly used for this purpose. However, the proportional contribution of various major body segments to the total body surface area changes with obesity. Similarly infants have very large heads, altering the overall contribution of other body segments to the total body surface area.
Detailed body surface area measurements were made in 47 patients: 18 were of normal weight, 6 were moderately obese, and 23 were seriously obese. Published tables of similar measurements for infants were reviewed to determine how the rule of nines applied to these populations. The contribution of the major body segments to the overall body surface area was calculated and compared to estimates that would be derived for these segments from the rule of nines.
The rule of nines provides reasonable estimates of body surface area for patients ranging from 10 to 80 kg. For obese patients weighing more than 80 kg a rule of fives is proposed: 5% body surface area for each arm, 5 x 4 or 20% for each leg, 10 x 5 or 50% for the trunk, and 2% for the head. For infants weighing less than 10 kg a rule of eights applies: 8% for each arm, 8 x 2 or 16% for each leg, 8 x 4 or 32% for the trunk, and 20% for the head.
Various body parts differentially contribute to the total body surface area. Because these relationships remain relatively constant throughout growth, the rule of nines provides reasonable estimates for the determination of burned body surface area for most children and adults. These relationships break down for infants and obese adults and the proposed modifications to the rule of nines provide better estimates of surface area for these groups.
在烧伤患者的初始治疗过程中，烧伤面积的测量对于估算液体需求量和确定住院标准非常重要。“九分法”通常用于此目的。然而，随着肥胖程度的增加，身体各主要部位对总体表面积的比例贡献会发生变化。同样，婴儿的头部非常大，这改变了其他身体部位对总体表面积的贡献。
对47例患者进行了详细的体表面积测量：18例体重正常，6例中度肥胖，23例重度肥胖。查阅了已发表的婴儿类似测量表，以确定九分法如何应用于这些人群。计算了主要身体部位对总体表面积的贡献，并与根据九分法得出的这些部位的估计值进行比较。
九分法为体重在10至80千克之间的患者提供了合理的体表面积估计值。对于体重超过80千克的肥胖患者，建议采用五分法：双臂各占5%体表面积，双腿各占5×4或20%，躯干占10×5或50%，头部占2%。对于体重小于10千克的婴儿，采用八分法：双臂各占8%，双腿各占8×2或16%，躯干占8×4或32%，头部占20%。
身体各部位对总体表面积的贡献各不相同。由于这些关系在整个生长过程中相对保持不变，九分法为大多数儿童和成人烧伤体表面积的测定提供了合理的估计值。这些关系在婴儿和肥胖成人中不适用，对九分法提出的修改为这些人群提供了更好的表面积估计值。
