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.

Trial registration: ClinicalTrials.gov NCT02952378.

Keywords: Burns (physiology), Capillary permeability (physiology); Serum albumin (pharmacokinetics, therapy).

Conflict of interest statement

The author RGH declares that he receives a research grant from Grifols for studies of 20% albumin. The other authors declare that they have no competing interests.

Figures

Fig. 1

a The blood haemoglobin and b plasma albumin concentration during and after infusion of 3 ml/kg of 20% albumin over 30 min in burn patients and volunteers. Data are the mean (SD)

Fig. 2

a Plasma dilution. b Plasma volume expansion divided by the infused volume of 20% albumin. c Changes in plasma oncotic pressure. d Changes in plasma albumin concentration. e Capillary leakage of albumin expressed as a percentage of the total amount of albumin in the plasma and f expressed as a percentage of the infused amount of albumin. All data are the mean (SD)

Fig. 3

Linear relationship between the burned area (as the percentage of total body surface area, TBSA) and a the C-reactive protein concentration in plasma, and b the interleukin-6 concentration in plasma. Each point is one patient in the burned group. c Logarithmic correlation between plasma albumin and the plasma colloid osmotic pressure. Each point is the mean values of 15 subjects. Frequent overlapping