Evaluation of feline red blood cells collected with an open system and stored for 35 days as whole blood units

Introduction: The increasing access to veterinary hospital blood banks and commercial sources of feline blood products means that transfusion therapy is more widely available to veterinarians and feline stored blood products are used more often. Despite the increasing availability of feline blood collected and stored for transfusion purposes, few studies have investigated storage lesions in feline whole blood (FWB) units and no study has evaluated hematological changes in FWB units. The objective of this study was to assess changes in feline RBCs collected and stored for transfusion purposes as FWB units. Methods:A prospective, laboratory invitrostudy wasconducted. Twelve nonleukoreduced FWB units were collected with an open system using three 20-mL syringes prefilled with citrate, phos- phate, dextrose, and adenine (CPDA-1) preservative-anticoagulant solution with ratio with blood of 1:7 from anesthetized feline blood donors. Units were stored in a blood bank dedicated refrigerator and sampled every 7 days (D7, D14, D21, D28) from collection (D0) to the end of storage (35 days, D35). At each time point, the following were evaluated: (1) hematological parameters (RBC, HGB, HCT, MCV, MCH, MCHC, RDW); (2) percentage of hemolysis; (3) morphological index, scored of 0 to 4 based on echinocyte transformation of the normal discocyte; and (4) aerobic and anaerobic blood culture. Results were statistically compared to D0, with t-test or Wilcoxon test, as appropriate with statistical significance set at P < 0.01. Results: There was no significant difference in hematological parameters at any time point with respect to D0. Significant increases were found in percentage of hemolysis and morphological index starting from 21 days of storage (P = 0.0002 and P = 0.0039, respectively). Mean hemolysis percentage value was less than 1% up to 21 days of storage. All blood cultures were negative for bacterial growth. Conclusion: RBCs in FWB units collected with an open system can undergo some significant hematological changes, but these results suggest that storage for up to 21 days is safe. In vivo studies are required to establish if these changes affect the ability of stored RBCs to circulate and provide adequate oxygen delivery after transfusion.