Spurious hyperphosphatemia in a patient with alteplase-locked central venous catheter

Abstract

Alteplase has been shown to be effective in preventing central venous access clotting in patients on hemodialysis. Because of a high phosphorus content in its excipient, it can inadvertently contaminate blood samples, leading the physician in care of the patient to erroneously increase dialysis time or change diet in order to control the pseudo-hyperphosphatemia.

Pseudohyperphosphatemia in a patient with relapsed multiple myeloma after bone marrow transplantation: A case report

“…Pseudohyperphosphatemia has also been reported in serum undergone prolonged refrigeration, the contamination of heparin or recombinant tissue plasminogen activator in the blood sample, treatment with liposomal amphotericin B, in vitro hemolysis with phosphate release from red blood cells, and the presence of hyperbilirubinemia or hyperlipidemia; however, none of these factors presented in our patient.…”

Severe Hyperphosphatemia in a Patient with Mild Acute Kidney Injury

“…Excess binding of phosphate to certain paraproteins or the actual physicochemical property of the paraprotein or both have also been implicated as a cause of pseudohyperphosphatemia [11][12][13][14]. As for heparin and alteplase-contaminated blood samples, phosphate is therein present as a pH buffer agent [15][16][17]. In the case of hemolysis or any other forms of cell death including tissue infarction and rhabdomyolysis, hyperphosphatemia may be expected as phosphate is a predominant intracellular anion which is released with cell lysis.…”

Hemodialysis in Children

“…Alteplase must be completely aspirated before the catheter is next used for dialysis. This is important not only because of its anticoagulant properties but also because of its phosphate content, so that a spuriously high phosphate level can be obtained if it is not thoroughly removed before blood sampling [34].…”