Clinical and biochemical changes during exchange transfusion.

The development of exchange transfusion has greatly altered the prognosis of haemolytic disease of the newborn and the procedure is now accepted as being essential in cases of any severity. It is carried out wherever the criteria for operation are fulfilled and by operators of varying skill and experience. The difficulties associated with blood transfusion have received increasing attention in recent years, and its employment is beset with problems not only of cytology and serology but of microbiology, biochemistry, allergy, dynamics, religion and race. Some of these are greatly increased by the volume of blood used in exchange transfusion. Considering that the infant may be perfused with stored blood of altered chemistry in quantities of up to three times his own blood volume, it is surprising perhaps that it can be done at all. Hazards such as sepsis, air embolism, portal-vein thrombosis and perforation of the umbilical vein have been described, but are fortunately uncommon. Circulatory overloading is an ever-present danger in the profoundly anaemic infant, and it may be precipitated by conducting the exchange transfusion too rapidly. Deterioration and even death, however, may occur in infants whose pre-operative condition gave rise to no concern. Such clinical deterioration was observed in 40% of the cases transfused by Walker and Neligan (1955), and it did not appear to be related in any simple way to the baby's initial condition, to birth weight, to the technical difficulties encountered or to the rate of exchange. Moreover, Walker (1955) was led to believe, from inquiries received by him, that unexpected death was commoner over the United Kingdom than he had previously thought. Signs of clinical disturbance which had been observed by one of us (J. W. F.) during exchange transfusions at the Simpson Memorial Maternity Pavilion, Edinburgh, between 1948 and 1953, prompted us to undertake a joint study of a series of infants during operation. Plan of Investigation