After the publication of our early reports on hemodilution perfusion,1-4 Cooley et al5 suggested its usefulness for expediency in pulmonary embolectomy and recently used it routinely for total body bypass.6 DeWall and Lillehei7 and DeWall et al8 constructively elaborated on this subject. Our comparative studies of two series of patients who had open-heart surgery with the aid of extracorporeal circulation using blood primes or 5% dextrose in water primes did not reveal the superiority of either method.9 The unfavorable theoretical and experimental attributes of blood primes did not materialize in our small series of patients. It is possible that the use of low priming volumes has obviated some of them, and it is conceivable that with larger series these disadvantages will become apparent. However, these studies demonstrated that 5% dextrose in water primes compare favorably with the conventional and traditional blood primes. This report