The use of recalcified citrated whole blood - a pragmatic approach for thromboelastography in children

Background: Thromboelastography (TEG) is an established way of monitoring the coagulation status of children and adults requiring blood products during surgery. Serial measurements are performed using a nearside machine and blood product prescription may be titrated against changes in TEG. There may also be useful applications when the patient is remote from the TEG machine but these are limited because TEG is usually performed on fresh native whole blood within 6 min of venepuncture. Citrated whole blood can be used for TEG if transport time is more than 6 min. We wished to establish whether TEG parameters for citrated whole blood were comparable with those of native whole blood in healthy children. Methods: Blood was obtained from 14 healthy children undergoing minor surgical procedures, at the time of intravenous cannula insertion for anaesthesia. Each sample was divided: TEG was performed on part of the sample in its fresh native state at 6 min and second portion of the sample was citrated, kept at room temperature and TEG was performed at 30 min after recalcification. Results: There was a significant difference in TEG parameters (r, k, alpha, MA and LY30) for fresh native whole blood and recalcified citrated whole blood (paired t-test). Conclusions: The normal range for fresh native whole blood TEG parameters is well established, which is routinely used in practice. There was a significant difference between TEG parameters for fresh native whole blood and citrated whole blood. We recommend that a specific normal range be established for citrated whole blood to enable it to be used in clinical practice.