Adjusting body weight for edema in severely burned patients.

Abstract

Weight loss is difficult to quantify in critically ill burn patients, as the presence of edema can mask changes in dry body weight. We sought to estimate dry body weight using measured weights adjusted for reported extremity edema. We evaluated patients with at least 20% total body surface area (TBSA) burns admitted to our intensive care unit over a 3½-year period. Body weights were collected for this analysis from admission to the time of a recorded dry weight after wound healing. Extremity edema was collected at the time of each weight measurement and was categorized into three groups: (1) no edema, (2) 1 + pitting edema, (3) 2 + or 3 + pitting edema. Logistic regression yielded the following formula for estimating dry weight (in kg): 0.66 x measured body weight + 25 - (3 for 1 + pitting edema or 4 for 2 + or 3 + pitting edema of either upper extremity) - (4 for any pitting edema to either lower extremity) (p < 0.01, R² = 0.81). These results may allow us to better estimate dry body weight changes in our edematous patients with severe burns. Nutrition goals can be adjusted earlier, when appropriate, based on these estimated dry body weight changes.