Regional citrate anticoagulation with continuous renal replacement therapy as a cause of hypercalcemia

Clinical relevance Awareness of the causes of hypercalcemia is essential for timely diagnosis of calcium disorders and optimal treatment. Citrate is commonly used as an anticoagulant during continuous renal replacement therapy (CRRT). Accumulation of citrate in the systemic circulation during CRRT may induce several metabolic disturbances, including total hypercalcemia and ionized hypocalcemia. The aim of the present study is to increase awareness of citrate accumulation and toxicity as a cause of hypercalcemia by relating three cases and reviewing the pathophysiology and clinical implications. Observations We utilized electronic health records to examine the clinical cases and outlined key studies to review the consequences of citrate toxicity and general approaches to management. Conclusions Citrate toxicity is associated with high mortality. A safe threshold for tolerating hypercalcemia during citrate anticoagulation is not clearly defined, and whether citrate toxicity independently increases mortality has not been resolved. Greater attention to citrate toxicity as a cause of hypercalcemia may lead to earlier detection, help to optimize the management of systemic calcium levels, and foster interest in future clinical studies.