Prediction of platelet counts with ROTEM-sigma in cardiac surgery

Excessive bleeding is common after cardiac surgery. According to transfusion algorithms based on ROTEM results (TEM International Inc., Munich, Germany), platelet transfusion is recommended when FIBTEM amplitude is normal and EXTEM amplitude is reduced. The aim of this study was to evaluate whether ROTEM (TEM International Inc.) parameters may predict accurately platelet counts in cardiac surgery patients, and to determine which of these parameters is the most useful for predicting platelet counts.

In this retrospective single center study data from 83 patients who underwent cardiac surgery were reviewed. We analyzed the results of patients for whom ROTEM (TEM International Inc.) and conventional laboratory tests were performed simultaneously. The derived ROTEM (TEM International Inc.) parameter PLTEM was used to estimate platelet count; PLTEM is calculated by subtracting FIBTEM from EXTEM. Correlation between ROTEM (TEM International Inc.) variables and platelet counts were determined. Logistic regression analyses were performed to predict platelet counts.

ROTEM A5 values show a high linear correlation with MCF values. PLTEM has a strong linear correlation with platelet counts. According to our results for PLTEM A5<32 mm the probability of platelet count <150×10⁹/L is 100%, for PLTEM A5<27 mm the probability of platelet count <100×10⁹/L is nearly 80%, and for PLTEM A5<22 the probability of platelet count <75×10⁹/L is 70%.

This study demonstrates the reliability of considering early ROTEM (TEM International Inc.) results and the feasibility of using PLTEM A5 to predict platelet counts and so, improve our ability to decide the need of platelet transfusion in cardiac surgery patients.