How to Stabilize the Level of& ;Ionized Calcium and Citrate during Plateletpheresis

Abstract

Background and objectives: Citrate reactions are uncomfortable and potentially dangerous to apheresis donors. Reduction of citrate increases comfort, but may lead to platelet clumping. Materials and methods: We describe a protocol for stepwise reduction of the volume of ACD-A injected during plateletpheresis. This protocol has been carried out in 45 healthy donors with the Cobe 2997 (Cobe) cell separator, and in 35 with the Fenwal-CS 3000 (CS). Results: Using this protocol, during the first hour of platelet collection, ionised calcium decreased on average by 18% for CS and by 18.4% for Cobe. During the second hour, Ca²⁺ and citrate ion concentration did not change with either Cobe or CS (about 65% of citrate ion load is eliminated). We observed mild signs of neuromuscular hyperexcitability in only 22% and 28% of donors with Cobe and CS, respectively. We also found a significant reduction of phosphate ions (p < 0.0001) at the end of the procedures. Conclusions: With this stepdown citrate reduction protocol, we obtained a significant reduction of injected citrate without the complication of platelet clumps.

Clinically relevant hypokalaemia, hypocalcaemia, and loss of hemoglobin and platelets during stem cell apheresis

“…In contrast to other studies a platelet transfusion was never indicated. This finding does not confirm previously published data, which suggested a mean or median loss of 47%, 52%, or 63% [12,19,22], respectively, with regard to LVL in both adults or children using the COBE Spectra cell separator. In our hands, only four of two hundred leukaphereses resulted in post-collection platelet counts < 20 × 10 9 /L.…”

“…Approximately 50% of the total calcium bound to serum proteins, mainly albumin, whereas 50% is in the ionized physiologically active form which could be measured accurately by ion selective electrodes [17]. Several investigators have published data which confirms that the ionized calcium decreased on average by 15% to 25% during citrate-anticoagulated plateletpheresis [16,18,19]. In contrast, the results obtained by Passos-Coelho et al [20] are actually not comparable because of their individually adapted anticoagulation protocol as well as the preventive calcium administration strategy used.…”

Calcium and magnesium levels during automated plateletpheresis in normal donors

“…Although, the fall in tCa and tMg were modest and not significant, drop in iCa and iMg was statistically significant ( P < 0·001). Similar observations have been made by previous workers (Toffaletti et al ., 1985; Mercan et al ., 1997; Farrokhi et al ., 1998). Despite this fall, no adverse donor reactions were observed in our apheresis donors.…”

“…Citrate known to chelate cations, particularly the free bioactive blood calcium needed by the coagulation factors, also chelates magnesium (Mg) (Bennett et al ., 1993). The reduced calcium (Ca) and Mg, in most of the donors, are considered physiologic and of little consequences (Walser, 1961; Farrokhi et al ., 1998; McLeod et al ., 1998). However, repeated platelet donations or during prolonged plateletpheresis, citrate accumulation may outpace its metabolism, resulting in hypocalcaemia or hypomagnesaemia, which may cause significant donor discomfort (Elin, 1994; Mercan et al ., 1997).…”

Treatment for the decline of ionized calcium levels during peripheral blood progenitor cell harvesting

“…Current apheresis apparatuses enable almost 10,000 mL of blood from a donor to be processed in about 3 hours. It has been reported that 65 percent of the citrate administered during plateletpheresis is biologically metabolized, about 10 percent goes to a collection bag, and 25 percent accumulates in the donor's blood 10 . According to Szymanski, 11 because the serum citric acid concentration is in inverse proportion to ICa at the time of plateletpheresis, the decrease of ICa is thought to be caused by infused citrate.…”