Effects of polycythaemia and haemodilution on circulation in neonates

Haemodilution in nine neonates resulted in significant mean (SEM) decrease of packed cell volume (0.67 (0.01) to 0.55 (0.01)) and increases in cardiac output (250 (16) to 308 (25) ml/min/kg) and blood flow velocities of the internal carotid artery and the coeliac artery (+20%). However, red cell flows in the aorta, carotid and coeliac arteries did not change during haemodilution, thereby indicating that haemodilution did not improve oxygen transport.