ABNORMALITIES OF HEMOSTASIS IN PATIENTS WITH LIVER CIRRHOSIS
Autori:
Matea Majerović, Ana Boban, Marina Premužić, Davor Radić, Ivana Knežević-Štromar, Agata Ladić, Željko Krznarić, Nadan Rustemović, Rajko Ostojić
Sažetak
Do početka 90-ih godina prevladavalo je uvriježeno mišljenje da su bolesnici s uznapredovalom jetrenom bolesti prirodno autoantikoagulirani i time zaštićeni od tromboembolijskih zbivanja. Međutim, novim saznanjima dugogodišnja je paradigma srušena. U bolesnika s cirozom jetre paralelno je reducirana sinteza prokoagulansa i endogenih antikoagulansa, dok je produkcija ekstrahepatalno sintetiziranih faktora, važnih za proces zgrušavanja i fibrinolize, očuvana. U stabilnoj jetrenoj bolesti sustav je „rebalansiran”, ali funkcionira u uskom rasponu homeostaze, što ga čini izuzetno fragilnim te ga i minimalni stres može uvesti u neželjeni ekstrem, trombozu ili krvarenje. Uz navedeno niz je drugih čimbenika koji prate jetrenu bolest, kao što su hemodinamske promjene, oštećenja drugih organa, ponajprije bubrega, te sklonost infekcijama, a koji pomiču ravnotežu prema sklonosti krvarenju ili pojačanom zgrušavanju. Konvencionalni laboratorijski testovi nisu prikladni za procjenu rizika od krvarenja u cirozi, rizični čimbenici za razvoj tromboze nisu nedvojbeno dokazani, a sigurnosni profil antitrombotskih lijekova u cirozi nije precizno utvrđen jer su ti bolesnici uglavnom isključeni iz velikih kliničkih studija. Zbog svega navedenoga dijagnostički i terapijski pristup u ovom je kontekstu kompleksan te nalaže timski rad hematologa, hepatologa i u fazi operativnog liječenja anesteziologa. U ovome preglednom radu osvrnut ćemo se na mehanizme poremećaja hemostaze i fibrinolize u bolesnika s cirozom jetre, incidenciju tromboembolijskih zbivanja, laboratorijsku dijagnostiku te profilaktičke i terapijske opcije u okviru internističke skrbi.
Summary
Until the beginning of the 90ies, it was believed that patients with liver cirrhosis were auto-anticoagulated and thus protected from thromboembolic events. However, new discoveries have broken the longstanding paradigm. In deranged hepatic function there is a reduced synthesis of procoagulants and endogenous anticoagulants, however, extrahepatally synthesized hemostatic and fibrinolytic factors are disproportionately affected. In stable disease hemostatic system is ”rebalanced’’ but fragile, therefore, even a minimal stress can promote bleeding or thrombosis. Also, there are many concomitant factors, such as hemodynamic changes, other organ affection, namely kidney, and predisposition to infection, that shift the balance towards either bleeding or thrombosis. Conventional laboratory tests are not sufficient for evaluation of the bleeding risk, prothrombotic risk factors are not clearly identified, and safety profile of antithrombotic drugs is not precisely evaluated since cirrhotic patients are mainly excluded from big clinical trials. For all that is said, the diagnostic and therapeutic approach in this context is complex and requires teamwork of a hepatologist, hematologist and in a phase of operative treatment, the anesthesiologist. In this review article, we will discuss mechanisms of hemostatic and fibrinolytic abnormalities of liver cirrhosis, the incidence of thromboembolic events as well as prophylactic and therapeutic options in the setting of conservative treatment.
