The effect of flow rate and catheter diameter on hemolysis during blood transfusions using canine packed red blood cells.

Objective: To evaluate the degree of hemolysis in canine packed RBCs at varying catheter sizes and flow rates as determined by RBC count, Hct, hemoglobin, creatine phosphokinase, and phosphorus. This study hypothesized that changes in flow rate and catheter diameter would change the degree of hemolysis.

Sample: A fresh unit of canine RBCs.

Procedures: A fresh unit of purchased canine packed RBCs was run through an IV infusion pump through 5 different catheter sizes (16, 18, 20, 22, and 24 gauge) at 5 different rates (50, 250, 500, 750, and 999 mL/h). Each sample was submitted for a CBC and chemistry, and RBC count, hemoglobin, hematocrit, creatine phosphokinase, and phosphorus were specifically evaluated to assess for the degree of hemolysis.

Results: Compared to the control, flow rate did not significantly affect the degree of hemolysis. Smaller catheter sizes had a significantly increased hemolysis (P < .05) based on variables to evaluate hemolysis (RBC count, Hct, hemoglobin, creatine phosphokinase, and phosphorus). This study's hypothesis was upheld in association with the catheter diameter but was rejected with flow rate.

Clinical Relevance: Blood transfusions are a common practice in veterinary medicine as treatment of anemia and hemorrhage. Hemolysis was greater when small catheter sizes were used. Larger catheters are recommended when feasible when performing transfusions.