A Double (Exchange Transfusion-Carbon Clearance) Model for Testing Post-Resuscitation Reticuloendothelial Function

A double exchange transfusion-double carbon clearance method was evaluated for assessing reticuloendothelial (RE) function following exchange transfusion with hemoglobin solutions. Fifty percent of estimated blood volume (3% body weight) was withdrawn from anesthetized Sprague-Dawley rats and isovolumically replaced with shed blood (SB, control), lysed shed blood (LB, pos. control), human stroma-free hemoglobin solution (SFH), or polyhemoglobin solution (PHS). Thirty minutes after the exchange transfusion, colloidal carbon was injected intravenously and its vascular clearance followed for 1 hour. Then, the 50% exchange transfusion was repeated and the second carbon clearance measured. The intravascular carbon clearance constants, K, and clearance half-times, T1/2, were calculated and compared. No apparent differences in RE function were seen among the groups after the initial exchange transfusion. However, following the second exchange transfusion significant (P< 0.05) slowing of carbon clearance was observed in lysed blood treated animals. The RE function of SFH or PHS treated animals were not different (P< 0.05) from that of SB animals. A double exchange transfusion-double carbon clearance method seems to reveal changes in RE function that are not apparent after a single exchange transfusion and clearance test.