Liver Failure Flashcards
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
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?
Definition of liver failure.
May be recognised by the developoment of coagulopathy ( INR > 1.5) and encephalopathy.
Definition of acute liver failure.
Hyperacute = 7 days or less onset
Acute = 8-21 days onset
Subacute = 4 to 26 weeks onset
Definition of chronic liver failure.
Starts with acute liver failure/disease on going effects beyond 6 months
Common causes of acute liver failure..
Resolves in 6 months due to
Hep A, E, CMV, EBV (viral)
Drug induced liver injury (DILI)
Common causes of chronic liver failure.
May progress to cirrhosis.
Alcohol
Hep C
Non-alcoholic steatohepatitis (NASH)
Autoimmune (PBC, PSC, AIH)
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
Signs of liver failure.
Jaundice
Hepatic encephalopathy
Fetor hepaticus
Asterixis
Constructional apraxia
Signs of chronic liver disease suggest acute-on-chronc liver failure
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
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
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
USS findings of cirrhosis.
Coarse texture
Nodularity
Splenomegaly or ascites
Causes of liver failure when ALT >500.
Viral
Ischaemia
Drug-induced (paracetamol very common)
Autoimmune
Causes of liver failure when ALT 100-200.
Non-alcoholic steotohepatitis
Autoimmune hepatitis
Chronic viral hepatitis
Drug induced liver injury
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
