Randomized placebo‐controlled study of oral calcium carbonate supplementation in plateletpheresis: II. Metabolic effects

Abstract

Plateletpheresis induces marked acute metabolic effects, with sustained changes evident up to 24 hours after the completion of apheresis. Oral Ca supplementation exerts a significant but clinically modest impact on selected laboratory variables associated with these effects. Further studies are indicated to examine the long-term impact of plateletpheresis, with or without Ca supplementation, on donor Ca balance and bone density.

Complications of donor apheresis

“…Physiologically, this dose was also associated with the greatest improvement in ionized and total calcium levels among the doses examined (1, 2, and 4 g) [8]. While improving paresthesias, in multivariate analysis, the oral administration of calcium was not associated with a reduction in overall symptom development and did not effect the occurrence of more severe symptoms [13].…”

“…Interestingly, this compensatory mechanism may be limited with intact parathyroid hormone levels reaching their maximum within 30 min of the start of collection without a subsequent increase despite a continued decline of ionized calcium [7]. A final mechanism that compensates for the effects of citrate is that there also appears to be mobilization of ionized calcium bound to serum albumin [8].…”

“…Factors that have been found to influence the rate of citrate reactions in donor and therapeutic apheresis include alkalosis due to hyperventilation [5], the type of anticoagulant solution used with ACD-A having more reactions than ACD-B [12], the rate of infusion of the anticoagulant solution [5], the amount of citrate infused [5], and the donor's serum albumin level prior to the start of the collection procedure [8]. It has also been reported that intermittent flow hemapheresis procedures tend to have a greater frequency of citrate reactions, as there is a higher rate of citrate infusion when the separation chamber is emptied, as compared to continuous apheresis procedures.…”

“…The administration of oral calcium carbonate and its effects on citrate toxicity have recently been examined by Bolan et al [8,13] These authors found that the administration of 2 g of calcium carbonate was associated with a statistically significant reduction in the severity of paresthesias [13]. Physiologically, this dose was also associated with the greatest improvement in ionized and total calcium levels among the doses examined (1, 2, and 4 g) [8].…”

“…Bolan et al noted that in addition to the acute metabolic effects of citrate infusion, sustained changes in calcium metabolism, up to 24 hours after the completion of the procedure, are also seen [8]. These changes included altered bone metabolism demonstrated by changes in alkaline phosphatase, osteocalcin, intact parathyroid hormone, and 1,25-dihydroxyvitamin D levels and raised concerns about the potential for long-term effects on bone metabolism [8].…”