Influence of cross-match on posttransfusion packed cell volume in feline packed red blood cell transfusion

Objective - To evaluate the influence of major cross-match on transfusion efficacy based on the change in PCV following packed red blood cell (pRBC) administration in cats. Design - Retrospective study from January 2000 to December 2010. Setting - University Teaching Hospital. Animals - Two hundred nine cats received 233 type-specific pRBC transfusions as treatment for anemia. Forty-three transfusions were cross-match compatible and 190 were not screened with cross-match. Interventions - Pretransfusion major cross-match. Measurements and Main Results - Signalment, body weight, dosage of pRBC transfusion, pretransfusion PCV, posttransfusion PCV, IV fluid volumes administered between the measurement of the pretransfusion PCV and posttransfusion PCV, time delay between pretransfusion PCV measurement and transfusion administration, time between administration of transfusion and posttransfusion PCV measurement, and major cross-match testing data were extracted from the medical records of cats receiving pRBC transfusions and were evaluated for their influence on posttransfusion PCV scaled to dose of pRBC administered. The mean pretransfusion PCV was significantly lower for cross-match compatible transfusions (13.7 +/- 4.2%) compared to noncross-matched transfusions (16.1 +/- 4.5%; independent samples t-test, P < 0.0001). The PCV increase posttransfusion scaled by dose was significantly greater for cross-match compatible transfusions (1.02 +/- 0.51%/mL/kg) than for noncrossmatched transfusions (0.74 +/- 0.65%/mL/kg; independent samples t-test, P = 0.0093). Of age, dose of pRBCs, cross-match status, reason for transfusion, pretransfusion PCV, and dose of IV fluids administered between the pretransfusion and posttransfusion PCV, only pRBC dose, cross-match status, and pretransfusion PCV were independent predictors of change in PCV with transfusion on multiple regression analysis (coefficient = 0.507, P < 0.0001; coefficient = 1.64, P = 0.041; coefficient = -0.235, P = 0.0009, respectively). Conclusions - In this retrospective study, administration of type-specific, cross-match compatible pRBC transfusions resulted in significantly greater increases in the posttransfusion PCV when compared to administration of typed, noncross-matched pRBCs. Future prospective studies evaluating the effect of cross-match on transfusion efficacy in cats are warranted.