Plasma volume expansion after infusion of 5%, 20% and 25% albumin solutions in patients.

Fifty grams of albumin were infused into patients in the immediate post-operative period as either 5, 20 or 25% solutions. With all three solutions the increase in plasma volume was 500 ml or 11 ml/g of retained albumin, which is less than the normal water-binding capacity of albumin found in studies in vitro and in some clinical studies. This might be explained by a blocking of the water-binding capacity of the albumin or by the action of other unknown mechanisms, when albumin is given in an amount exceeding the losses. The expansion of the plasma volume did not depend on the concentration of the solutions given but only on the amount of albumin given and the deficit in plasma volume. Since albumin is a good plasma expander and a drug with a few secondary effects it is recommended in the treatment of shock. We prefer the 5% solution, which contains an electrolyte solution and is more easily infused, because of its low viscosity.