Inotropic effect of different albumin solutions on isolated papillary muscle

We used a papillary muscle assay to study the inotropic effect of albumin solution. Unlike specially prepared citrate-free solutions, commercial preparations produced a negative inotropic effect. This is because their high citrate concentrations bound much of the calcium, so that little ionized calcium was available for physiologic processes. Citrate-free albumin did not show any inotropic effect on isolated papillary muscle. The amount of albumin normally used for resuscitation should not have enough citrate to depress ionized plasma calcium. Our experiments showed no evidence for primary myocardial depressant action of a commercial albumin preparation.