Left heart dimensions in anemic cats and dogs before and after blood transfusion.

Abstract

BACKGROUND: Whether anemic cats and dogs with increased left heart dimensions are at higher risk of transfusion-associated circulatory overload, and the effect of blood transfusion on left heart dimensions in naturally occurring anemia is unknown. HYPOTHESIS/OBJECTIVES: To evaluate the effect of blood transfusion on left heart dimensions in clinically relevant anemia. ANIMALS: Twenty dogs and 20 cats presenting to a university veterinary teaching hospital. METHODS: In this prospective observational study, anemic dogs and cats requiring blood transfusion were included. Packed cell volume (PCV), total solids, and echocardiography were performed before and within 24&#x2009;hours of blood transfusion. Signalment, bodyweight, disease process, transfusion duration and volume, and prior treatments were recorded. Nonparametric statistics were reported as median [range]. Post hoc Bonferroni correction set significance at P&#x2009;<&#x2009;.006. RESULTS: After transfusion, PCV increased in cats (12% [6-16] to 18% [10-33], P = .001) and dogs (14% [7-24] to 25% [9-37], P = .001), heart rate decreased in dogs (104&#x2009;bpm [86-166] to 87&#x2009;bpm [56-138], P&#x2009;<&#x2009;.001), and fractional shortening decreased in cats (57.1% [36.0-84.7] to 41.0% [28.1-69.6], P = .002) and dogs (33.79% [19.33-62.79] to 31.89% [19.06-51.47], P = .006). Left ventricular internal diameter in systole increased in cats (6.5&#x2009;mm [2.7-9.8] to 7.9&#x2009;mm [5.3-11.1], P = .001). Normalized left ventricular internal diameter in diastole (1.48 [1.25-1.79] to 1.57 [1.33-2.00], P = .001) and systole (0.87 [0.58-1.19] to 1.00 [0.74-1.36], P = .001) increased in dogs. Incidence of volume overload did not differ before (14/20 cats, 70%; 9/20 dogs, 45%) or after (12/20 cats, 60%; 11/20 dogs, 55%) transfusion (P = .64). CONCLUSIONS AND CLINICAL IMPORTANCE: Blood transfusion is well tolerated when signs of volume overload are present before transfusion.