Effect of moderate haemodilution with fluosol-DA or normal saline on ampicillin kinetics in the rat

The effects of haemodilution with either Fluosol-DA or normal saline on renal excretion and glomerular filtration have been studied in the rat. Ampicillin clearance and renal creatinine clearance were used as in-vivo measures of renal excretion and glomerular filtration, respectively. Rats were moderately exchanged with either fluid and evaluated after 0.5, 24, 48, or 72 h. After exchange, ampicillin clearance was higher, but not significantly different, and the apparent volume of distribution was increased significantly in some groups. These changes are consistent with the effects expected when plasma protein binding is reduced by haemodilution. The percent of ampicillin recovered in urine and the renal creatinine clearance were not statistically different in any group. Thus, moderate haemodilution with either fluid did not change renal function compared with unexchanged animals.