Abstract
The dilution of excessive amounts of blood under alkalemic conditions causes blood to accumulate in the early stages following a cardiopulmonary bypass(CPB)or in recirculation circuits after modified ultrafiltration(MUF). We investigated changes in the shape(echinocytes)of red blood cells(RBC)in alkaline tris hydroxymethyl aminomethane(THMA)buffer at pH 7.5, 8.0, 8.5, and 9.0 using inverted microscopy. We then examined the ability of THMA buffer containing 0.5% or 5.0%(final concentrations)colloidal albumin and starch at pH 7.5 and 9.0 to protect against changes in the shape of RBC. The rates at which echinocytes appeared were significantly reduced from 13.9% in THMA buffer at pH 9.0 to 3.5% and 1.2% in THMA buffer containing 0.5% and 5.0% albumin, respectively(p<0.01 for both), and to 7.6% and 2.1% in that containing 0.5% and 5.0% starch(p<0.05 and p<0.01), respectively. These findings suggest that adding albumin and artificial colloid to CPB filling liquid might protect against blood accumulation caused by echinocytes.
