Effects on divalent cations of a haemodilution technique using ACD blood in paediatric patients undergoing bypass open-heart operations.

MULTIPLE DERANfJEMENTS OF CATION HOMEOSTASIS have been reported with the use of haemodilution techniques in patients undergoing open-heart surgery with cardiopulmonary bypass, t'~ However, there have been few reports on alterations in ionic calcium ~.~ or magnesium, in particular when relatively large volume acid citrate dextrose blood primes are used in children. This has special relevance in view of the chelating effect of citrate on both calcium and magnesium ions, s,~ It is the ionized fractions of calcium and magnesium which determine their effect on cell membrane stabi]ity, myocardial contractility, and on the central and peripheral nervous system as well as on skeletal and smooth musculature. '~ The present report deals with plasma and urinary changes in divMent cations occurring in paediatrir patients undergoing open-heart operation with eardlopulmonary bypass in which ACD or heparinized blood primes were diluted with 5 per cent glucose in 0.9. per cent sodium chloride,