Colloid infusions reduce glomerular filtration in resuscitated burn victims

Objective: Colloids are used clinically to minimize edema yet may have detrimental consequences on glomerular filtration. The purpose of this study is to assess the renal and hormonal effects of colloid supplementation in the fluid resuscitation of burn victims. Design: Analytic cohort study. Material and Methods: Immediately following their 24 hour post-burn fluid resuscitation with Ringer's lactate, six burn patients (% total body surface area burn 30-57%) were given primed, continuous infusions of inulin and p- aminohippuric acid for 6 hours. Albumin (25% solution, 3 mL/kg/h) was given for the final 4 hours of study. Measurements and Main Results: Albumin infusion increased plasma volume by 37%; however, glomerular filtration rate decreased by 32% (p < 0.05). There was no significant change in urine output, sodium excretion, or effective renal plasma flow. Plasma volume expansion with albumin normalized elevated basal levels of aldosterone and plasma renin activity. Conclusions: These findings illustrate that despite substantially increasing plasma volume, colloid infusions reduce glomerular filtration and may limit any associated diuresis. Furthermore, this study demonstrates that hormonal regulation of blood volume remains intact after moderate burn injury.