Liver Failure Flashcards by Don J

Functions of the liver.

Glycogen storage, production and release of glucose, absorbs fats, fat soluble vitamins and iron.
Production of cholesterol

Dissolves dietary fats

Bilirubin

Production of clotting factors

Detoxification - drug excretion and alcohol breakdown

Immune function via Kupffer cells

Production of albumin and other binding proteins

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Important history in liver disease.

Blood transfusions prior to 1990 in the UK?

IV drug user?

Operations and vaccination with dubious sterile procedures?

Sexual history

Medications (ALL OF THEM)

FH of liver disease, diabetes or IBD

Obesity and other features of metabolic syndrome

Alcohol?

Foregin travel?

Tattoos?

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Definition of liver failure.

May be recognised by the developoment of coagulopathy ( INR > 1.5) and encephalopathy.

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Definition of acute liver failure.

Hyperacute = 7 days or less onset

Acute = 8-21 days onset

Subacute = 4 to 26 weeks onset

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Definition of chronic liver failure.

Starts with acute liver failure/disease on going effects beyond 6 months

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Common causes of acute liver failure..

Resolves in 6 months due to

Hep A, E, CMV, EBV (viral)

Drug induced liver injury (DILI)

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Common causes of chronic liver failure.

May progress to cirrhosis.

Alcohol

Hep C

Non-alcoholic steatohepatitis (NASH)

Autoimmune (PBC, PSC, AIH)

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Causes of liver failure.

Infections - Hep B, C, CMV, A, E, yellow fever, leptospirosis

Drugs - Paracetamol overdose, halothane, isoniazid etc…

Budd-Chiari, Veno-occlusive disease

Toxins

Alcoholic fatty liver disease

PBC

PSC

Haemochromatosis

Autoimmune hepatitis

alpha-antitrypsin def.

Wilson’s disease

Malignancy

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Signs of liver failure.

Jaundice

Hepatic encephalopathy

Fetor hepaticus

Asterixis

Constructional apraxia

Signs of chronic liver disease suggest acute-on-chronc liver failure

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Grades of hepatic encephalopathy

Grade 1 - Psychomotor slowing, constructional apraxia, poor memory and reversed sleep pattern

Grade 2 - Lethargy, disorientation, agitation and irritability, asterixis.

Grade 3 - Drowsy

Grade 4 - Coma

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Investigations of liver failure.

Acute vs chronic doesn’t matter. Investigations are alike.

Bloods - FBC, LFTs, Clotting (thrombocytopenia is a sensitive marker for liver fibrosis), glucose, paracetamol levels, Hep serology, CMV and EBV serology, ferritin, ceruloplasmin levels, autoantibodies, alpha-antitrypsin, coeliac serology, TFTs and lipids.

Microbiology - Blood cultures, urine culture, ascitic tap for MC&S of ascites.

Radiology - CXR, abdo USS, Dopples flow studies

Neurophysiology - EEG

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If the LFTs suggest a cholestatic abnormality, what should be done?

Ultrasound to assess if the ducts are dilated (obstructive) or not.

USS can also be used to assess cirrhosis

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USS findings of cirrhosis.

Coarse texture

Nodularity

Splenomegaly or ascites

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Causes of liver failure when ALT >500.

Viral

Ischaemia

Drug-induced (paracetamol very common)

Autoimmune

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Causes of liver failure when ALT 100-200.

Non-alcoholic steotohepatitis

Autoimmune hepatitis

Chronic viral hepatitis

Drug induced liver injury

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Causes of cholestatic liver failure with dilated ducts.

Gallstones

Malignancy

Causes of cholestatic liver failure with non-dilated ducts.

Alcoholic hepatitis

Cirrhosis due to PBC, PSC or alcohol

Drug induced liver injury due to antibiotics

Commonest causes of chronic liver failure.

Alcoholic liver disease

Non-alcoholic steatohepatitis

Viral hepatitis (B&C)

Chronic liver failure more common in women.

Autoimmune hepatitis and PBC

Chronic liver failure more common in men.

PSC which is associated with IBD

Cause of chronic liver failure that occurs earlier in men.

Haemochromatosis

Causes of chronic liver faliure that occurs only in adolescents and young adults.

Wilson’s disease

Anti-LKM autoimmune hepatitis

Management of liver failure.

Beware of sepsis, hypoglycaemia, GI bleeds/varices and encephalopathy.

Nurse with a 20 degree head-up tilt in ITU. Protect airways.

Insert urinary and central venous catheters to help assess fluid status.

BLOs hourly

Check FBC, U&Es, LFTs and INR daily

10% glucose IV 1l/12h to avoid hypoglycaemia and do glucose daily.

Treat the cause.

If malnourished get dietician.

Treat seizures with phenytoin

Haemofiltration or haemodialysis if indicated.

Consider PPis as prophylaxis against stress ulceration

Complications of liver failure.

Cerebral oedema

Ascites

Bleeding

Infection

Hypoglycaemia

Encephalopathy

Treatment of liver failure with cerebral oedema.

ITU 20% mannitol IV and hyperventilate

Treatment of liver failure with ascites.

Restrict fluid Low salt diet Weigh daily Spironolactone

Blind treatment of infection in liver failure.

Ceftriaxone 1-2/24h Do not give gentamicin due to risk of renal failure.

Treatment of liver failure with hypoglycaemia.

If 2 mmol or less or symptomatic give 50 ml of 50% glucose IV and keep checking glucose levels regularly.

Treatment of liver failure with encephalopathy.

Avoid sedatives 20 degree head-up tilt in ITU Correct electrolytes Give lactulose 30-50ml/8h. Rifaximin 550mg/12h can also be given.

Explain Lactulose action to treat encephalopathy in liver failure.

Catabolised by bacterial flora to SCFA. This decreases colonic pH leading to entrapment of NH3 in the colon as NH4+ instead. This leads to reduction of NH3 and NH4+ levels in the blood.

Explain action of Rifaximin in treatment of encephalopathy in liver failure.

Non-absorbable oral antibiotic that decreases numbers of nitrogen forming gut bacteria.

What drugs to avoid prescribing in liver failure.

Avoid drugs that can cause constipation since it increases the risk of encephalopathy. Oral hypoglycaemics Saline-containing IVs Also mind Warfarin effects are enhanced Hepatotoxic drugs such as; paracetamol, methotrexate, isoniazid, azathioprine, phenothiazines, oestrogen, 6-mercaptopurine, salicylates, tetracycline, mitomycin.

Explain hepatic encephalopathy.

As the liver fails, nitrogenous waste (as **ammonia) builds up in the circulation** and passess to the brain. Astrocytes will clear it up by **converting glutamate to glutamine.** The **excess of glutamine** causes an **osmotic imbalance** and a shift of fluid into these cells. This leads to **cerebral oedema**

What is hepatorenal syndrome?

Cirrhosis+ascites+renal failure if all other causes of renal impairment has been excluded. Abnormal haemodynamics causes splanchnic and systemic vasodilation, but there is instead **renal vasoconstriction** because of the systemic vasodilation. Bacterial translocation, cytokines and mesenteric angiogenesis cause the splanchnic vasodilation and altered renal autoregulation is involved in the renal vasoconstriction.

Types of hepatorenal syndrome.

HRS 1 - Rapidly progressive deterioration in circulatory and renal function often triggered by other deteriorating pathologies. - Terlipressin can help hypovolaemia, haemodialysis might be needed. HRS 2is a more steady deterioration. TIPSS is usually indicated

King's College Hospital criteria in acute liver failure induced by paracetamol.

Arterial pH \< 7.3 24h after ingestion or all of the following; Prothrombin time \> 100s Creatinine \> 300micromol/L Grade III or IV encephalopathy

King's College Hospital criteria in non-paracetamol induced acute liver failure

PT \> 100s Or 3 out of the 5 following; Drug-induced liver failure Age \<10 or \>40 yo \>1 wk from 1st jaundice to encephalopathy PT \> 50s Bilirubin \> 300micromol/L