Changes in Serum Calcium Fractions and Citrate Concentrations During Massive Blood Transfusions and Cardiopulmonary Bypass

Abstract

Total serum calcium, its fractions and serum citrate concentrations were measured in children receiving massive blood transfusion for scoliosis surgery, and in other children undergoing open heart surgery with cardiopulmonary bypass. During scoliosis surgery, although up to 100% of blood volume was replaced, and no additional calcium salts were infused, serum ionized calcium concentration remained within normal limits, provided that infusion rates of blood did not exceed 30 ml kg-1 h-1. During cardiopulmonary bypass, in which citrate-containing blood priming solutions were used, serum ionized calcium concentrations decreased markedly during perfusion associated with extremely high serum citrate concentrations. Serum ionized calcium concentrations returned to normal by the end of bypass, but serum citrate concentrations remained five times the normal concentration 5 h after bypass.

Massive Transfusion and Its Influence on Oxygen Transport and Electrolyte Balance

“…These changes, however, are immediately reversible in such short periods of transfusion. The administration of 4 FFP/h over a period of 8 h leads to no hemodynamic impairment [88] and only to a small extent of hypocalcemia of 0.76 mmol [63]. Kinetic studies with infusions of citrate to dogs and men, in a dose corresponding to 3 FFP/5 min over a period of 20 min, led to a 10-20-fold increasing concentration of citrate and a decrease of both cardiac work and the systolic blood pressure.…”

Effects of Liver Function on Ionized Hypocalcaemia following Rapid Blood Transfusion

“…The recovery time for serum ionized calcium after blood transfusion in the SP patients was consistent with a previously reported time for patients with normal liver function. 34,36 In contrast, ionized hypocalcaemia in the LT patients who received PRBCs was more prolonged than expected and persisted 60 min after blood transfusion. When hypoalbuminaemia is considered, 26,37 -39 LT HS Chung, SJ Cho, CS Park Rapid blood transfusion-induced ionized hypocalcaemia in LT patients may have had an even more severe hypocalcaemia than normal patients.…”

“…33 Haemodynamic instability and abnormal hypocalcaemia may occur at blood transfusion rates > 30 ml/kg per h, and the hypocalcaemia usually recovers within 10 min if the transfusion rate decreases. 34,35 The current study was designed to consider this transfusion rate, but the hourly total blood transfusion volume and rate defined as massive transfusion was not attempted due to the risk of circulatory overload. The transfusion rate used in the SP group in the present study was, however, sufficient to make a meaningful difference in serum ionized calcium at T 1 compared with the SN group, in which blood was diluted using 0.9% normal saline instead of PRBCs.…”

Zitronensäure und ihre Alkalisalze [MAK Value Documentation in German language, 1998]

“…Etwa 70% des im Körper enthaltenen Zitrats sind im Knochen an Calcium gebunden (etwa ein bis mehrere Prozent der Knochenmasse) (Dickens 1941;Howland et al 1957;Lussier 1957;Saffran und Denstedt 1951 (Howland et al 1957;Ludbrook und Wynn 1958). Nach längerer intravenöser Infusion größerer Zitronensäuremengen kann die vollständige Elimination der verabreichten Dosis mehrere Stunden betragen (Abbott 1983;Driscoll et al 1987). Ursache dafür ist die Rückverteilung aus dem großen Verteilungsvolumen, weniger aus dem Knochen (Denlinger et al 1976).…”