Ionized calcium during plateletpheresis

The concentration of ionized calcium (Ca++) during platelepheresis was monitored when donors received 461 ± 95 (mean ± S.D.) ml of anticoagulant acid-citrate-dextrose (ACD), N.I.H. formula A. Most donors experienced mild subjective symptoms (perioral tingling) during reinfusion of autologous blood. The concentration of serum Ca++ before the procedure was 4.19 ± 0.203 (mean ± S.D.) mg/dl and it decreased to 3.27 ± 0.391 (mean ± S.D.) mg/dl after the procedure. Two of the 79 donors experienced more severe symptoms (nausea, lightheadedness) while ionized calcium was lower than 3 mg/dl. Mild hypocalcemic effects could be demonstrated by electrocardiography in most donors. When donors received 414 ± 28 (mean ± S.D.) ml of ACD, N.I.H. formula B, only some of them experienced perioral tingling during reinfusion of the autologous blood. The concentration of Ca++ before the procedure was 4.18 ± 0.14 (mean ± S.D.) mg/dl and it decreased to 3.66 ± 0.14 (mean ± S.D.) mg/dl after the procedure. These data indicated that ACD N.I.H. formula B promotes greater donor comfort and safety than does ACD, formula A. The data showed that hemodilution occurred immediately following the withdrawal of one unit of blood, prior to infusion of any intravenous fluids. The analysis of the data revealed also that both magnesium and calcium entered the intravascular compartment during plateletpheresis. Although the origin of the calcium ion entering the plasma could not be established, it appeared that at least part was derived from calcium-citrate complexes.