Fluid Retention and Burn Survival

The relationship between retained fluid and survival has previously been reported from our burn unit. Two hundred thirty cc/kg lean body mass accurately delineated survivors from nonsurvivors. Our previous study did not account for fluid lost through the burn wound. This study was undertaken to evaluate fluid retention per square meter of body surface area which has been corrected for fluid loss from the burn wound using a formula suggested by Mason et al. (11). Data collected from 95 adult patients with burns greater than or equal to 20% body surface area burn (mean age, 42.4 years; mean burn size, 37.7%), who were admitted to our burn unit between January 1978 and September 1985, were evaluated. All patients included in the study were adequately resuscitated and survived the initial 48 hours. A calculation of the total fluid retained during the first 48 hours postburn and estimation of fluid loss from the burn wound were made. A comparison was made between lean body retained fluid and surface area retained fluid. A positive correlation (r = 0.921; p < 0.001) was demonstrated between these two methods of assessing fluid retention. Fluid retention determined by either method resulted in a higher correlation with survival than any single predictor (age, per cent body surface area burned) of burn survival. Surface area fluid is as accurate as lean body fluid in predicting survival. Additionally, we determined that for the first 48 hours postburn, 4, 425 cc fluid retained per meter square body surface area accurately differentiated survivors from nonsurvivors. In the patients studied older than 60 years of age this value allowed us to predict survival 100% of the time. We suggest that cc fluid retained per meter square is a clinically valuable indicator of burn survival.