Concentration-dependent effect of hypocalcaemia on in vitro clot strength in patients at risk of bleeding: A retrospective cohort study

© 2016 British Blood Transfusion Society. Aim: It is uncertain whether hypocalcaemia is associated with an increased risk of bleeding. This study assessed the dose-related relationship between ionised calcium concentrations and in vitro clot strength measured by maximum amplitude (MA) on the thromboelastograph (TEG). Methods: A total of 610 patients who were at risk of bleeding or had active bleeding between 2010 and 2014 were considered in this retrospective cohort study. A scatter plot with Pearson correlation coefficient (r) and multiple linear regression was used to assess the dose-related relationship between ionised calcium concentrations and MA on the TEG. Results: The mean ionised calcium of the patients was 1·10 mmol L-1 (interquartile range: 1·04-1·17) and 235 (38·5%) of them had hypocalcaemia (1 mmol L-1, during critical bleeding is recommended.