ACUTE LIVER FAILURE. Aliakbarian M, M.D

Transcription

1 ACUTE LIVER FAILURE Aliakbarian M, M.D

2 Acute Liver Failure Definition Rapid deterioration of liver function resulting in altered mentation and coagulopathy in a patient without preexisting cirrhosis and with an illness of less than 26 weeks duration.

3 Acute Liver Failure. Fulminant hepatic failure Fulminant hepatitis Subfulminant liver failure Subacute hepatic necrosis Subacute liver failure Hyperacute liver failure

4 Index of Suspicion for ALF Clinical signs of moderate to severe hepatitis Laboratory findings including an increase in the prothrombin time of 4-6sec.(INR 1.5). Altered sensorium INR Altered Mental Status = ALF

5 Suspect ALF?...Admit to ICU

6 ALF Etiologies Viral Drug Poisoning Ischemia VOD Malignant Infiltrate Wilson s Disease Microvesicular steatosis AIH Hyperthermia OLT Partial hepatectomy

7 Viral Acute Hepatitis A-E Reactivation of HBV Chemotherapy Immunosuppresion Herpes simplex Varicella-Zoster EBV

8 Acute HAV and ALF ALF uncommon Frequency 0.01% - 0.1% in jaundiced patients ALF occurs early Survival (transplant- free) 75% Age related survival

9 Acute HBV and ALF HBV alone or with HDV co-infection (rare) Transplant-free survival is 23% Overall survival 77% because of transplantation

10 Drug Induced ALF Many drugs implicated Acetaminophen Halothone and derivatives INH/ Rifampin Tricyclics/ MAO inhibitors Phenytoin/ NSAID Increased risk: acetaminophen (as little as 2gms) + ETOH median dose: 13 gm Increased risk if drug continued after jaundice appears

11 Poisoning and ALF Amanita mushrooms (amanatoxins) - LD = 50 gms (3 mushrooms) - Toxins not destroyed by cooking - Rapid onset of HE in 4-8 days following severe emesis and diarrhea Solvents - chlorinated hydrocarbons Herbal remedies Yellow phosphorus

12 Obstruction of Hepatic Veins and ALF Budd-Chiari syndrome and thrombosis of hepatic veins VOD - Post BMT Chemotherapy, Irradiation

13 Other Etiologic Causes of ALF Wilson s Disease can be presenting feature usually in patients <20 yrs can occur if patient discontinued D-penicillamine for a few years

14 Other Etiologies (2) Microvesicular steatosis Acute fatty liver of pregnancy Reye s syndrome Drug Induced - Valproic acid AIH May appear as an acute hepatitis on initial presentation More common if anti-lkmi antibody present ASMA usually not present

15 Other Etiologies (3) Hyperthermia (Heat stroke) Direct thermal injury Hepatic ischemia due to -DIC -Perfusion defect OLT Poor presentation of donor liver Acute graft rejection Thrombosis - hepatic artery, hepatic vein, portal vein Partial hepatectomy Removal of 80% or more of healthy liver Removal of 50% or less in hepatic dysfunction

16 Evaluation & Diagnosis of Impending ALF History! History! History! Sexual contacts Pregnancy Risk Factors IDU Mushrooms Medications Travel Toxic exposures

17 HISTORY Family members with liver disease? Recent cold sores Onset of jaundice Work environment- toxic agents Hobbies Herbal products/dietary supplements

18 Physical Exam Determine presence or absence of pre-existing liver disease Hepatic tenderness Hepatic decompensation

19 Laboratory Tests (1) Drug screening ALT, AST, Alk Phos, Glu, Bilirubin Lytes, Albumin, Mg, Phos., CBC with differential Coags: PT, PTT Anti HAV IgM Anti HBc IgM/ Anti HBsAg/ Anti-HCV

20 Laboratory Tests (2) If under 35 years of age Ceruloplasmin Serum & urine copper Arterial blood gas Arterial lactate Pregnancy test Autoimmune markers ANA, ASMA, Ig levels HIV status Amylase & lipase

21 Liver Biopsy Reserved for diagnostic dilemma - AIH, HS (Transjugular approach)

22 Diagnosis of ALF Hallmarks - occurs simultaneously or in succession Altered mentation Clinical EEG Arterial Ammonia Coagulopathy PT 4 sec prolonged (INR 1.5) Arterial ph<7.3 if acetaminophen ingested (cause for immediate transfer for OLT)

23 Management of ALF (1) Directed towards prevention of complications ICU setting Central line(s)-10% dextrose Pulmonary artery pressure and CO Inform Transplant Service and transfer with onset of HE Monitor VS and urinary output (Foley) strict I&O Laboratory Testing every 4-6hr electrolytes, BUN, creatinine, CBC, platelets, PT, PTT, ALT, AST, T. bilirubin, Alk Phos, Albumin

24 Management (2) Maintain gastric ph above 5 - protonix IV Preparation for endotracheal intubation Prepare to initiate monitoring intracranial pressure Enteral feeding tubes for grade 3 or 4 coma

25 Cerebral Edema Cerebral Perfusion Pressure Mean Arterial Pressure ICP = Cerebral Perfusion Pressure (CPP) Ideal ICP<20-25mm Hg Ideal CPP>50-60mm Hg Imazaki, et al When CPP<40 for 2 hrs. 0 of 7 patients recovered When CPP>50 6 of 8 patients recovered Improved ICP first sign of spontaneous recovery

26 Management (3) Cerebral Edema & Intracranial Hypertension (Most serious complications of ALF) Clinical signs of elevated ICP (Intracranial Pressure) -sluggish pupillary response -increased limb-muscle tone -none Monitoring ICP -usually reserved for grade 3 or 4 coma -awaiting OLT

27 Management (4) Cerebral Edema - General Measures -quiet environment -elevate head avoid sedation (use restraints) -avoid Valsalva-like maneuvers -mental status assessments q1-2h -mannitol if signs of impending uncal herniation (0.5mg/kg, lolus q4-8h) when ICP<30-40mm -assisted ventilation (in all grade 3 and 4)

28 Multiple Organ Failure Hepatic damage Failure of clearance Endotoxemia increased risk of infection MOF Gut leak Activation of macrophages Tissue Circulating Release of Hypoxia changes cytokines TNF, IL-1, IL-6 Williams, Sem Liver Dis, Vol 16, No.4, 1996

29 Management (5) Hemodynamic Complications include: Hypotension, tachycardia, vascular volume decrease with capillary leak and vasodilation Volume expansion (central line) FFP or 4.5% albumin, 10% dextrose Maintain pulmonary capillary wedge pressure 12mm-14mm Hg Minimize salt solutions (ascites, interstitial accumulation) Inotropic/pressor support(epi, norepi, dopamine), but not vasopressin.

30 Management (6) Coagulopathy/Bleeding Diathesis FFP or platelets given in presence of bleeding Conventional treatment of GI bleeding DIC thrombocytopenia Metabolic Complications Prevent hypoglycemia Phosphate and magnesium levels monitored - replace early Enteral feeding, 60gm protein/24 hrs No role for high branched-chain AA Monitor for lactic acidosis secondary to tissue hypoxia, sepsis

31 Management (7) Renal Failure - In 42% to 82% of ALF poor prognostic sign - Rising creatinine and oliguria - Metabolites of acetaminophen are nephrotoxic leading to acute renal failure similar to ATN and loss of phosphate -HRS

32 Additional Complications ARDS Sepsis - Severe complement deficiency - Decreased PMN motility - Decreased Kupffer cell function and removal of endotoxins - Increased levels of TNF and IL-6

33 Prognostic Factors Dependent on Etiology Younger patients do better (<40 and >10) Presence of cerebral edema Delay between jaundice and HE of more than 3 weeks - poorer prognosis MOF - poor prognosis

34 Current Treatment Transplantation

35 OUTCOME RESULTS U.S. ALF STUDY GROUP 308 Patients Spontaneous Survivors n=132 (43%) Transplanted N=89 (29%) Died before Transplantation n=87 (28%)

36 Transplanted N=89 (29%) Alive N=75 (84%) Died N=14 (16%)

37 Approach to Suspected ALF Etiology and Pathogenesis Evaluation and Diagnosis Complications Management Prognosis Current and future treatment approaches