Comparison Between Thromboelastography and Conventional Coagulation Tests in Pediatrics With Chronic Liver Disease

* Compare between thromboelastography (TEG) and conventional coagulation tests (CCT) in children with chronic liver disease who admitted to Assiut University Children Hospital.
* Detect the advantages of TEG in predicting the risk of bleeding, assessing haemostasis and guiding blood product transfusion for each coagulation defect .

The liver is the largest solid organ in the body with a mass of 1200-1500 g. It develops embryologically as a glandular outgrowth of the primitive gut, forming also the largest gland of the body . The liver is the major site of synthesis of haemostatic factors and clearance of activated haemostatic factors . These factors are important to maintain dynamic balance of physiological haemostasis, including primary haemostasis (i.e. interaction between platelet \[PLT\] and vessel wall), coagulation cascade and fibrinolysis . Consequently, in patients with liver dysfunction, a complicated disorder of haemostatic system arises, causing both bleeding and thromboembolic complications .

Chronic liver disease (CLD) is a progressive deterioration of liver functions for more than six months, which includes synthesis of clotting factors, other proteins, detoxification of harmful products of metabolism, and excretion of bile . The spectrum of etiologies is broad for chronic liver disease, which includes toxins, alcohol abuse for a prolonged time, infection, autoimmune diseases, genetic and metabolic disorders . The common causes for chronic liver disease (CLD) in children are hepatitis B, hepatitis C, hepatitis D, autoimmune hepatitis and metabolic disorders like Wilson's disease and α-1 antitrypsin deficiency . In majority of the patients the etiology remains uncertain. Signs and symptoms of CLD can be nonspecific, such as fatigue, anorexia, weight loss, or depend upon the complication that the patient has developed. The three significant complications are because of portal hypertension (esophageal varices, ascites), hepatocellular insufficiency (e.g., jaundice, hepatic encephalopathy), and hepatocellular carcinoma .

Among complications of chronic liver disease: variceal bleeding, ascites, spontaneous bacterial peritonitis (SBP), hepatic encephalopathy, hepatorenal syndrome, hepatopulmonary syndrome and hepatocellular carcinoma (HCC) .

There are various scoring systems used to assess the severity of chronic liver disease .

Physiological haemostasis includes primary haemostasis, coagulation cascade and fibrinolysis, which are involved with various haemostatic factors. Haemostatic tests mainly include conventional coagulation tests (CCTs) and thromboelastography (TEG) test. CCTs mainly includes PLT count, PT, APTT, and fibrinogen (FIB), d-dimer and fibrinogen degradation products (FDP) concentrations. PLT count reflects primary haemostasis by quantitative assessment of PLT. PT and APTT reflect coagulation cascade by assessment of pro-coagulants involved in the extrinsic and intrinsic pathways, respectively. FIB concentration reflects coagulation cascade by quantitative assessment of FIB. D-dimer and FDP concentrations reflect fibrinolytic activity by quantitative assessment of d-dimer and FDP .

Thromboelastography (TEG), a whole blood viscoelastic test. TEG detects the clotting time, clotting kinetics and clot stability to more comprehensively evaluate haemostatic status by several parameters, mainly including reactive time (R), kinetic time (K), angle (α), maximum amplitude (MA) and lysis-30 . R reflects the activity of coagulation factors by detecting the time of fibrin formation. K and α reflect the fibrinogen function by detecting the rate of clot development. MA reflects the platelet function by detecting the maximum clot strength. Lysis 30 reflects fibrinolytic activity by detecting the degree of fibrinolysis .

Eligibility Criteria:
Inclusion Criteria:

* Patients with chronic liver disease of any aetiology as (congenital hepatic fibrosis, liver cirrhosis, autoimmune hepatitis, Wilson disease, metabolic liver disease and others ).
* Patients aged 6m- 18y .

Exclusion Criteria:

* Patients who received transfusion of blood products within 48hr prior to sample collection.
* Patients who are on therapy with antiplatelet drugs or anticoagulants.
* Patients with history of primary disease with coagulation disturbance (paroxysmal nocturnal hemoglobinuria, polycythemia, idiopathic thrombocytopenia, haemophilia.
* Patients with concomitant chronic kidney disease.