Abstract title	

Recruitment of extravascular fluid by hyperoncotic albumin in volunteers

Background

Hyperoncotic albumin may be used to recruit oedema from the interstitial fluid space, but its effectiveness is unclear. This question was studied during infusion experiments in healthy volunteers.

Method

Fifteen healthy volunteers received an infusion of 3 ml/kg of 20% albumin over 30 minutes. The urinary excretion was measured and venous samples were taken for measurement of haemoglobin (Hb), haematocrit, colloid osmotic pressure and albumin on 15 occasions over a period of 5 hours. Based on these data, mass balance calculations were used to estimate the plasma dilution and the mobilisation of fluids from the tissues.

Results

Maximum effect of plasma dilution was reached 20 minutes after the end of the albumin infusion. Plasma volume dilution and total diuresis during the 5 hours of blood sampling was effectively increased by Albumin 20%. The plasma dilution after 300 minutes correlated inversely to the total diuresis. Total mobilised fluid from the tissues at 300 minutes was 3.4 ± 1.2 ml for every infused ml of albumin 20%.

Conclusion

20% Albumin significantly increases the blood volume by recruiting interstitial fluid as well as increasing the diuresis. There is a delay of 20 minutes, after the end of the infusion, until maximum plasma dilution is reached.

The duration of the dilution effect expands beyond the 5 hours measuring time.