Impact of experimental hypercalcemia on routine haemostasis testing

Area of Science:

• Clinical Chemistry
• Hematology
• Coagulation Science

Background:

• Standard hemostasis testing uses a fixed blood to anticoagulant ratio based on normal calcium levels.
• The effect of hypercalcemia on citrate anticoagulant capacity is not well understood.
• This study investigated the impact of experimentally induced hypercalcemia on routine coagulation tests.

Purpose of the Study:

• To determine if hypercalcemia affects the accuracy of standard coagulation tests.
• To assess the necessity of adjusting the citrate-anticoagulant ratio in hypercalcemic patients.
• To evaluate the reliability of hemostasis testing under conditions of elevated calcium.

Main Methods:

• Pooled citrated and lithium-heparin plasmas were divided into three groups.
• Groups were supplemented with saline, saline and calcium chloride, or calcium chloride to simulate varying calcium levels.
• Total and ionized calcium, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen were measured.

Main Results:

• Calcium concentrations increased in all supplemented plasma aliquots.
• Ionized calcium remained immeasurable in citrate plasma aliquots despite supplementation.
• No significant bias was observed in PT, APTT, or fibrinogen results in citrate plasma, staying within quality specifications.

Conclusions:

• Experimental hypercalcemia does not introduce significant bias in first-line coagulation tests.
• Adjusting the blood to anticoagulant ratio in hypercalcemic patients is not justified.
• Routine hemostasis testing remains reliable even in the presence of severe hypercalcemia.