Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_35_библиотеки_им_акад_М_И_Перельмана

The bleeding risk in ESLD patients is typically rst assessed using interview and physical examination. Medical history should focus on history of bleeding including epistaxis, spontaneous bleeding (e.g., gingival bleeding while brushing teeth), esophageal variceal bleed, history of easy bruising, history of deep vein thrombosis (DVT), pulmonary embo­lism (PE), or portal vein thrombosis (PVT), and history of cancer, particularly hepatocellular carcinoma (HCC). Physical exam ndings suggestive of increased bleeding risk may include bruises, petechiae, or spontaneous bleeding from vascular insertion sites.

Historically, practitioners would prophylactically correct a prolonged PT and elevated INR prior to surgery by admin­istering plasma, due to concerns for excessive bleeding risk. However, this assumption is likely incorrect. Clinical and laboratory studies have shown that INR does not correlate to bleeding risk in cirrhotic patients [6]. Routine correction of hemostasis abnormalities by plasma or platelet transfusion in patients with liver disease is not indicated and may even do more harm than good by disrupting the patients’ so-called rebalanced hemostasis discussed above [5]. In addition, when plasma is given to correct an elevated INR, it is com­monly under-dosed. The dose of plasma to correct an ele­vated INR is 10–15 ml/kg. However, providers give an average of 1–2units which exposes the patient to all the risks of transfusion, including transfusion-associated acute lung injury (TRALI), transfusion-associated circulatory overload

More sophisticated point-of-care tests of coagulation such as viscoelastic testing including thromboelastography (TEG) and rotational thromboelastometry (ROTEM) repre­sent a helpful technique for evaluating whole blood clotting. Use of viscoelastic testing is likely superior to traditional PT/INR and PTT for evaluating cirrhotic patient’s underly­ing hemostatic abnormalities due to the tests’ ability to quantify clot initiation, propagation, and breakdown in real time to identify specic abnormalities. The ROTEM test contains several component tests: EXTEM which analyzes the extrinsic coagulation pathway, INTEM which analyzes the intrinsic pathway, FIBTEM which analyzes the contri­bution of brinogen to coagulation, and APTEM which detects brinolysis. An additional test, HEPTEM, can be used to detect heparin effects [ tests for liver transplantation are the EXTEM, FIBTEM, and APTEM.Commonly used thromboelastometry parameters include the clotting time (CT) representing clotting factor activation, clot formation time (CFT) and α-angle which correlate with factor amplication and brin cross-linkage, Amplitude at 5 and 10minutes (A5 and A10) and maximum clot rmness (MCF), represent clot strength and correlate to platelets and brinogen activity on the EXTEM, and brin­ogen on the FIBTEM.Maximum lysis (ML) indicates the maximum amount of clot breakdown [9]. One distinct advantage of ROTEM over standard laboratory assessment is the speed; results (including CT, CFT, A5, A10) can be obtained within 5–10minutes of starting the assay. A5/A10 have been shown to have an excellent correlation with thrombocytopenia and hypobrinogenemia and may poten­tially guide early transfusion of relevant blood products dur­ing liver transplantation [10]. Evidence supports the use of these tests to guide transfusion in actively bleeding patients without liver disease and has shown a reduction in the amount of transfusion and decreased risk of postoperative thrombosis [8, 11, 12]. In liver transplant surgery, utilization of ROTEM to guide transfusion may decrease blood loss and plasma transfusion [13–15]. ROTEM-guided hemor­rhage prediction in ESLD is an area of ongoing research with promising results thus far [16, 17]. Evidence as to any long-term benets in morbidity and mortality with of the use of thromboelastometry in liver transplantation is lim­ited. One case control study of ROTEM in 303 liver trans­plant patients showed that use of ROTEM reduced blood