Severity of anaemia and operative mortality and morbidity.

In a case-control study of 125 surgical patients who declined blood transfusions for religious reasons operative mortality was inversely related to the preoperative haemoglobin level, rising from 7.1% for patients with levels above 10 g/dl to 61.5% for those with levels below 6 g/dl. Mortality rates were also related to blood loss during surgery, rising from 8% for patients who lost less than 500 ml to 42.9% for those who lost more than 2000 ml. Both preoperative haemoglobin level and operative blood loss should be considered in assessing the need for preoperative transfusion. In our study no patient with a haemoglobin level above 8 g/dl and operative blood loss below 500 ml died.