Relationship of Physical Symptoms, ECG, Free Calcium, and Other Blood Chemistries in Reinfusion with Citrated Blood

Abstract

Changes in ECG, free C (CaF) and other biochemical parameters were measured during reinfusion of citrate anticoagulated blood in 12 subjects undergoing plateletpheresis. Physical symptoms during the procedure were also monitored. The CaF correlated best with the Q-oTc interval as compared to the Q-oT, Q-Tc or Q-T interval. While the correlation was significant (r [correlation coefficient] = 0.592, P < .001), the Q-oTc could not predict the CaF. A number of other blood constituents changed during plateletpheresis, with most directly related to citrate administration or hemodilution. Severe physical symptoms were found in 1 subject and no symptoms in 3. In the subjects without symptoms the changes in Q-oTc, Pi, alkaline phosphatase and glucose through the plateletpheresis procedure were different from changes in all subjects. The decrease in glucose level was the most striking single factor correlating with the lack of physical symptoms during the citrate-induced hypocalcemia associated with plateletpheresis. Monitoring of the ECG cannot substitute for direct measurement of CaF in citrate-induced hypocalcemia. The physical symptoms associated with similar levels of hypocalcemia are variable. Glucose level may be a marker for the effects of citrate-induced hypocalcemia. Lowered citrate loads during plateletpheresis appear warranted.