Effect of syringe and aggregate filter administration on survival of transfused autologous fresh feline red blood cells.

Objective: To assess the effect of transfusion using a syringe and microaggregate filter on short-term survival and circulating half-life of autologous feline RBCs.

Design: Prospective, internally controlled, observational study.

Setting: A University Teaching Hospital

Animals: Six apparently healthy, owned cats.

Interventions: Blood collection by jugular venipuncture. Transfusion with labeled, autologous, fresh RBCs.

Measurements And Main Results: Anticoagulated whole blood (35 mL/cat) was collected in 2 equal aliquots. RBCs were washed and labeled at 2 different biotin densities, before suspension in autologous plasma. Labeled RBCs were then transfused using 2 methods, gravity flow and pump delivery using a 20 mL syringe and 18 μm microaggregate filter. Whole blood samples were collected from each cat at 2-hour intervals for 12 hours following completion of the transfusions. Additional samples were collected at weekly intervals up to 6 weeks to assess circulating half-life of the transfused cells. Cell survival was assessed via flow cytometry. The proportion of transfused cells remaining in each of the 2 populations was measured. Biotinylated RBCs were readily detected in all cats over the 6-week sampling period. There was a significant decrease in both populations of labeled cells over the 6-week period (P < 0.01), as expected. There was no difference in probability that the RBCs would survive up to 12 hours immediately following transfusion, and no significant difference in survival between the 2 groups over 6 weeks. The average half-life of all labeled cells was approximately 23 days.

Conclusions: We conclude that, in contrast to findings from dogs, transfusion of autologous feline RBCs using a syringe + aggregate filter method does not significantly impact short- or long-term survival of the transfused cells.