Haemodynamic changes with blood transfusion in chronic severe anaemia

Circulatory behavior in chronic, severely anaemic patients on volume loading is not precisely known. Twenty young male subjets with hook-worm anaemia, (Hb 2 to 5 gm %), without any complications were transfused with 300 or 600 ml of whole blood at 3 6 or ml/mt. Haemodynamic study was done before and immediately after. Blood volume was low, intracardiac pressures normal or minimally abnormal, cardiac output raised and vascular resistances low. After transfusion, there was a small but significant rise in arterial and mixed venous oxygen content, oxygen transport, heart rate, pulmonary wedge and mean polmonary arterial pressures and fall in % coeffcient of oxygen utilisation. Central venous pressures rose only with bigger transfusion. Change in cardiac output was related to the output before transfusion. Three subjects with cardiac index above 7 1/min had a fall and 6 of 7 below 7 1/min. a rise. Fall is perhaps related to the rise in blood oxygen content. It is argued that it is not an index of cardiac failure, as is often believed. Changes in pulmonary pressures are more sensitive than central venous pressure. One of our subjects died suddenly a day after uneventful study. Existing knowledge of haemodynamic status in severe anaemia and the change on transfusion helps little in explaining such deaths and others due to pulmonary oedema during or shortly after small to large transfusions. Further work in this field aiming to study changes in myocardial function and dynamic pressure volume relation in the vascular system is required.