[Magnesium levels in the blood of patients during surgery using cardiopulmonary bypass].

The use of gelatinol as a basic diluent for perfusion caused hypermagniemia (an increase in total magnesium plasma level-MgT-to 1.72 and in its ionized fraction -Mg2+- to 0.93 mmol/l) which persisted in the early postoperative period. Normal or elevated MgT plasma level does not exclude possible lowering in Mg2+ level.