Hemodynamic Tolerance and Plasma Volume Variations during Plasma Exchange

Little is known about mechanisms of systemic hypotension frequently reported during plasma exchange (PE). Type of substitution fluids may interfere with hemodynamic tolerance. In a prospective study, right heart catheterization was performed during 18 PE by filtration with isovolumic substitution. Blood volume was measured with 51 Cr tagged erythrocytes and plasma volume (PV) calculated from hematocrit. Substitution fluids were either albumin (A; n = 9) or A + gelatin (A + G; n = 9). In both groups, PE induces significant (p < 0.01) decreases of mean arterial pressure: group A: - 21 ± 14%; group A + G: - 23 ± 15%; of pulmonary wedge pressure: group A: - 41 ± 33%; group A + G: - 36 ± 22%; of cardiac index: group A: - 38 ± 18%; group A + G: - 25 ± 15%. Plasma volume also decreases after PE: group A: - 13.5 ± 4%; group A + G: - 18.5 + 4%. None of the variations are significantly different between the two groups. So we think that substitution with albumin alone has no advantage for hemodynamic tolerance.