Modification to single catheter exchange transfusion technique.

A simple modification to the standard 'in-out' exchange transfusion technique is described which requires cannulation of the umbilical vein only, yet provides many of the theoretical and practical advantages of a 2-catheter arteriovenous technique. The advantages include a reduction of cardiovascular disturbance; a reduction of the inevitable pressure changes in the portal venous system (probably important in the pathogenesis of complicating necrotizing enterocolitis); administration of alkali or drugs diluted in donor blood; accurate assessment of balance; a more efficient exchange; and general ease of management allowing better clinical observation of the infant.