An Observational Study of Hemostatic Profile during Different Stages of Liver Transplant Surgery Using Laboratory-Based Tests and Thromboelastography.

BACKGROUND

Liver produces most of the blood coagulation factors, so it is not surprising to see a deranged coagulation profile in patients receiving liver transplants. Besides standard laboratory methods to evaluate coagulation profile, point-of-care assays are being used regularly since their results are rapidly available. However, sparse information is available on the comparability of point-of-care coagulation assays with laboratory coagulation assays in this special setting. In this study, our aim is to observe the changing hemostatic profile during different stages of liver transplant surgery using laboratory-based tests and thromboelastography (TEG).

METHODS

Fifty patients undergoing living donor liver transplantation surgery were selected. Coagulation tests (prothrombin time [PT], activated partial thromboplastin time [APTT], platelet count, and fibrinogen) and TEG were performed at various intervals during liver transplant surgeries - before induction of anesthesia, 2 h into dissection phase, 30 min into anhepatic phase, 30 min after reperfusion of homograft, postoperative - at closure of surgery, 12 h postoperative, and 24 h postoperative. Statistical analysis and Pearson correlation were performed between laboratory-based coagulation tests and TEG, and their pattern through various stages of the surgery analyzed.

RESULTS

Platelet count and fibrinogen have a significant positive correlation with TEG in almost all phases of liver transplant. PT and APTT have a positive correlation with TEG until uptake of new liver and predominantly negative correlation after that. However, this correlation is significant only before induction of anesthesia and anhepatic phase.

CONCLUSIONS

TEG can be used to estimate platelet count and fibrinogen concentrations in all phases but PT and APTT only before induction and anhepatic phase of liver transplant surgery. The decision regarding transfusion of blood products should be based on a combination of the clinical assessment of surgeon and anesthesia personnel combined with results from laboratory and TEG.