Effects of Extra Corporeal Circuit Prime on Electrolytes Balance and Clinical Outcome Following Cardiac Surgery

About 6000 heart operations are performed in Sweden every year. A heart-lung machine is used almost exclusively in all heart operations. This machine fills the role of heart and lungs during surgery while the heart is stopped. The extra corporeal circuit (ECC) prime results in hemodilution, as assessed from the decrease in haematocrit, electrolyte concentration and total protein content. This hemodilution is an unavoidable consequence of the use of a heart-lung machine with nonblood ECC prime. The alteration of the patient´s blood volume and electrolytes is affected by the prime solution and can be maintained within normal limits. There are no clear recommendation regarding prime components and numerous prime solutions are in use worldwide. The aim of this study is to investigate whether the use of mannitol in heart-lung machine prime has an effect on electrolytes levels and osmolality when compared with patients who receive no Mannitol.