Comparison of thromboelastography with routine laboratory coagulation parameters to assess the hemostatic profile and prognosticate postoperative critically ill patients

BACKGROUND: Patients undergoing surgery often demonstrate coagulopathy. Usually, this derangement in coagulation is assessed by the laboratory based evaluation of blood samples. However, collection of samples, their transportation to the lab, and the analyses can result in several errors and as such these tests may not be representative of the complete coagulation process. In our study, we compared the lab coagulation parameters with the point of care TEG indices and attempted to compare the outcome prediction of our patients based on the TEG indices and the various practiced ICU scores. METHODS: A prospective, observational study was conducted between May 2014 and May 2015. Fifty adult patients who had undergone noncardiac surgery and had developed new onset 2 or more than 2 system involvement in the postoperative period were enrolled in the study. They were sampled simultaneously for lab coagulation parameters (PT, APTT, INR, fibrinogen, and platelet count) and TEG on days 1, 3, and 5 post admission. RESULTS: There were significant differences between TEG and lab coagulation parameters on day 1 of the study 1 (P = 0.004) but not on days 3 and 5. On days 1 and 3 of our study, the ICU scores (SOFA and APACHE II) were significantly higher in the group with deranged TEG parameters (P = 0.003, 0.02). The patient subpopulation with deranged TEG parameters had significantly higher mortality at median survival time (P = 0.014). Such a difference was not found in patients with higher ICU scores or deranged lab coagulation times. We constructed a ROC curve and arrived at a cutoff value of the reaction time to predict the median survival day mortality. CONCLUSIONS: The agreement between TEG and conventional lab parameters remains poor but the TEG parameters seem to be more deranged in sicker patients. As the relationship between the overall severity of illness and derangement in the hemostatic system has been well explored in medical literature, TEG may be a more appropriate modality in such patients.