Acute on chronic liver failure - Clinical profile, precipitating factors, outcome and predictors of mortality

Abstract

INTRODUCTION : Liver failure can develop acutely in a patient with no preexisting liver disease (Acute Liver Failure) or as an acute decompensation of a chronic liver disease. Recently it has been noted that a subgroup of patients develops acute deterioration in previously compensated cirrhosis and are considered to have acute on chronic liver failure (ACLF). This deterioration is secondary to an acute event and multi organ failure leading to increased mortality at three months. In contrast to chronic liver disease these patients have a rapid downhill course with the development of multiorgan failure and high short term mortality. One important concept in this group of patients is the potential reversibility. The term reversibility does not mean that underlying chronic liver damage is reversible, but rather the acute deterioration of the liver function due to the precipitating event is reversible. The pathophysiological basis ACLF was initially described by Jalan [et al.]. There is no clear cut definition of ACLF in the western literature. Asia Pacific association of study of liver (APASL) has defined it as acute hepatic insult manifested by jaundice and coagulopathy complicated within four weeks by ascites or encephalopathy. The cause for acute deterioration can vary from infectious causes like sepsis, viral hepatitis and non hepatotrophic viruses’ infection or noninfectious causes like alcohol, drugs, gastrointestinal bleeding, toxins and surgery. There is controversy 2 regarding whether sepsis can precipitate ACLF or it is the result of ACLF. Though numerous studies have been published in western literature on cirrhotic patients admitted to ICU, most of them have not differentiated organ failure as part of progressive worsening in end stage cirrhosis from acute on chronic liver failure. There are very few studies from India in this subject. H Garg [et al.] have recently published a prospective study on ACLF patients. Etiology of chronic liver disease and the acute precipitants differ between various geographical locations. AS ACLF carries a high mortality it is essential to identify prognostic factors. In general it has been noted that score evaluating the severity of disease like APACHE and SOFA score are better than liver specific score like Child Pugh score. Management of ACLF requires good intensive care to prevent the development of organ failure or to support the failing organs. Use of various extracorporeal liver support systems have been studied in various studies. Even though there is an improvement in biochemical parameters and in hepatic encephalopathy ,there is no significant survival benefit. Liver transplantation is the only curative treatment. This prospective study aims to look at the clinical profile, precipitating factors, outcome prognostic factors in ACLF admitted in a tertiary care hospital. AIM OF THE STUDY : The aims of the study are as follows, 1. To study the clinical profile of patients with acute on chronic liver failure, 2. To study the underlying chronic aetiology and acute precipitants, 3. To study the 30 day and 90 day mortality, 4. To study the various predictors of mortality. CONCLUSION : Acute on chronic liver failure is a unique entity. It is characterized by rapidly deteriorating course in a previously diagnosed or undiagnosed chronic liver disease with a potential for reversibility. Our study shows that it has high short term mortality (44%). Most common aetiology for underlying chronic liver disease in our centre is alcoholic liver disease (64.5%) followed by hepatitis B (20%) and other causes. The most common acute precipitant is super added alcoholic hepatitis (82%) in alcoholic liver disease and reactivation of hepatitis B (66%) in chronic hepatitis B. Other causes of acute worsening include acute hepatitis E and drug induced liver injury. Most common cause of death is the multi organ failure. Increasing number of organ failures is associated with increasing risk of death. High serum bilirubin, high INR, renal failure, low sodium, and high CRP are all poor prognostic markers. SOFA and MELD are better predictors of mortality than Child score. Early referral for liver transplantation is essential in patients at high risk of death. Acute on chronic liver failure is a disease which is still being defined and large prospective studies are needed to better delineate the acute precipitants and the prognostic markers.