Hemodynamic evaluation of blood transfusion in chronic severe anemia with special reference to speed of transfusion.

Left ventricular filling pressure (LVFP) as reflected by pulmonary capillary wedge pressure (PCWP) was measured in 40 adult cases of chronic severe anemia (CSA) before and after transfusion of 1 unit of whole citrated blood, using Swan-Ganz monitoring catheters. The cases were randomized into 4 groups of 10 each. Blood was transfused at a rate of 2 ml, 5 ml and 10 ml/min in groups A, B and C, respectively. In group D, blood transfusion (BT) was given at 5 ml/min but this group received, in addition, 40 mg furosemide intravenously just prior to the transfusion. Pretransfusion PCWP was normal in all the cases. Following BT the "wedge" pressure increased significantly in the first 3 groups, the rise being proportionately greater with faster transfusions (15.8, 20.9 and 32.2% in groups A, B and C, respectively). In group D, however, PCWP actually decreased by 21.7% (p less than 0.001). As far as we know, this is the first study in which a definite and significant rise in PCWP has been documented following transfusion of blood even at conventional speed (group A). The implications of such an increase in "wedge" pressure as well as the observation that it can be completely blocked by furosemide are discussed. On the basis of these observations it is recommended that intravenous furosemide should be administered routinely before any BT in cases of CSA. Such practice will also permit blood to be transfused at a comparatively faster speed, without jeopardizing patient safety.