Plasma volume expansion and capillary leakage of 20% albumin in burned patients and volunteers

Abstract

Background: Burn injury is associated with a long-standing inflammatory reaction. The use of albumin solutions for plasma volume support is controversial because of concerns of increased capillary leakage, which could aggravate the commonly seen interstitial oedema. Methods: In the present open controlled clinical trial, an intravenous infusion of 20% albumin at 3 mL/kg was given over 30 min to 15 burn patients and 15 healthy volunteers. Blood samples and urine were collected for 5 h. Plasma dilution, plasma albumin and colloid osmotic pressure were compared. Mass balance calculations were used to estimate plasma volume expansion and capillary leakage of fluid and albumin. Results: The patients were studied between 4 and 14 (median, 7) days after the burn injury, which spread over 7-48% (median, 15%) of the total body surface area. The albumin solution expanded the plasma volume by almost 15%, equivalent to twice the infused volume, in both groups. The urinary excretion exceeded the infused volume by a factor of 2.5. Capillary leakage of albumin occurred at a rate of 3.4 ± 1.5 g/h in burn patients and 3.7 ± 1.6 g/h in the volunteers (P = 0.61), which corresponded to 2.4 ± 1.0% and 2.5 ± 1.2% per hour of the intravascular pool (P = 0.85). The median half-life of the plasma volume expansion was 5.9 (25th-75th percentiles 2.7-11.7) h in the burn patients and 6.9 (3.4-8.5) h in the volunteers (P = 0.56). Conclusions: Albumin 20% was an effective volume expander in patients at 1 week post-burn. No relevant differences were found between burn patients and healthy volunteers. Trial registration: EudraCT 2016-000996-26 on May 31, 2016.