Hepatology Flashcards
Abnormalities in which LFTs indicate hepatocellular disease?
Alanine aminotransferase (ALT)
Aspartate aminotransferase (AST)
Abnormalities in which LFTs indicate cholestatic disease?
Alkaline phosphatase (ALP)
Gamma glutamyl transferase (GGT)
Abnormalities in which LFTs indicate a problem with synthetic function?
Albumin
Bilirubin
PT (INR)
Why is there a relative deficiency of ALT compared to AST in alcoholic liver disease
ALT is pyridoxine dependent and alcoholic patients are pyridoxine deplete
Where are ALT and AST found in the body?
ALT is liver specific
AST is found in the liver, myocardium, skeletal muscle, kidneys, brain, pancreas, erythrocytes
What do elevated ALP indicate
ALP is found in liver, bone, placenta and thus raised levels can indicate cholestatic liver disease, accelerated growth in puberty, Pagets disease, osteoblastic metastases e.g., prostate cancer, pregnancy
What do elevated GGT levels indicate
GGT is specific to the liver so can help confirm that a raised ALP is due to liver disease
Also indicates alcohol abuse or use of certain medications
What does an elevated PT suggest
Prolonged prothrombin time/INR –> increased risk of bleeding
- Lack of liver synthetic function (vitamin K dependent clotting factors)
- Vitamin K deficiency (malnutrition, malabsorption 2˚ to pancreatic insufficiency/biliary disease)
- Vitamin K inhibition due to anticoagulation e.g., warfarin
How to differentiate between vitamin K deficiency or liver disease as a cause of prolonged PT
Reversal of coagulopathy with 10mg of vitamin K suggests that PT elongation is not due to synthetic problem
Other synthetic tests will be abnormal in liver disease and pt is often hypoglycaemic
Risk factors for viral hepatitis
IVDU
Sexual behaviour esp. MSM
Migration from high prevalence area
Blood transfusion prior to routine screening/in country without routine screening
What simple features on exam may suggest alcoholism
Dupuytren’s contracture
Partotidomegaly
What does acanthosis nigricans suggest
Insulin resistance
Consider metabolic syndrome, fatty liver, T2DM, PCOS
An AST/ALT ratio above 2 suggests
Alcoholic liver disease
Transaminases of > 1000 U/L (very high) suggest
Acute viral pancreatitis
Paracetamol toxicity
Ischaemic hepatopathy
Acute biliary obstruction
Medications/drug induced liver injury (DLI)
Transaminases > 500 are practically never due to alcohol alone - alternative cause should be sought
Symptoms suggesting chronic liver disease
May be no symptoms
Abdominal/RUQ pain, anorexia, nausea, weight loss
Malaise, fatigue, myalgia, fever
Pruritus, dark urine, pale stools, jaundice
Bleeding
Signs suggestive of chronic liver disease
Hepatocellular dysfunction: spider naevi, palmar erythema, leukonychia, gynaecomastia, testicular atrophy, body hair loss, hepatomegaly
Portal HTN: ascites, peripheral oedema, hepatomegaly, splenomegaly, caput medusae, petechiae, variceal bleeding
Poor synthetic function: ecchymoses, peripheral oedema
End stage liver disease: progressive severe fatigue, encephalopathy (asterixis, fetor coma)
Constant RUQ (or epigastric) pain suggests
Liver disease e.g., hepatitis
Severe, episodic RUQ (or epigastric) pain suggests
Biliary disease
How does celiac disease affect LFTs
Moderate ALT and ALP elevation wth normal bilirubin
Explain bilirubin metabolism
Haem from RBCs is degraded by MOs –> biliverdin –> biliverdin reductase –> UCB –> binds albumin and moves to hepatocytes –> conjugated in 2 step process in ER by addition of a glucuronic acid molecule in each step catalysed by UDP-glucuronosyl transferase –> CB is then secreted into bile into SI –> converted by intestinal bacteria to urobilinogen 80% of which is excreted in faeces as stercobilin and 20% is not –> 10% of the remaining urobilinogen is exreted as urobilin by kidneys and 90% returns to liver via enterohepatic circulation
3 phases of bilirubin metabolism
Uptake
Conjugation
Excretion
When does jaundice occur
Normal levels of bilirubin = ~ 25umol/L (conjugated up to 5umol/L)
Jaundice occurs ~ 50umol/L
Common causes of hepatitis
HAV, HBV, HCV
Alcohol liver disease
NAFLD
Ischaemic hepatopathy
Drug induced hepatitis
Autoimmune hepatitis
Haemochromatosis, a1at deficiency, Wilsons disease
Common causes of cholestasis
Primary sclerosing cholangitis
Primary biliary cholangitis/cirrhosis
Common duct obstruction e.g., tumour, stone (choledocolithiasis), stricture
Infiltration e.g., maligancy, amyloid, sarcoid
Drug induced cholestasis
Assessment of jaundice/hyperbilirubinaenia
Clinical picture e.g., pruritus, pale stool, dark urine suggests intrahepatic/posthepatic cholestasis; hepatomegaly, RUQ pain, nausea, risk factors for hepatitis, fever suggests viral hepatitis etc.
FBC (leukocytosis may suggest infection e.g., cholangitis, anaemia may suggest haemolysis, abnormal mononuclear cells suggest EBV –> perform monospot, leucopaenia often occurs in viral hepatitis)
LFTs (hepatitis -> high AST and ALT vs extrahepatic obstruction –> high ALP and GGT)
- perform fractionation of bilirubin to get proportion of direct and indirect bilirubin
Viral markers (HAV, HBV, HCV, CMV, EBV, HIV)
USS to assess size of bile ducts (dilated in extrahepatic obstruction), level of obstruction, cause of obstruction
- can further Ix obstruction with MRCP or FNA for biopsy and pathological Dx
Consider autoantibodies e.g., AMA for PBC
Broad causes of jaundice
Haemolysis (excess of UCB)
Failure of hepatic uptake (e.g., rifampin)
Impaired conjugation e.g., impaired glucuronyl transferase action in Crigler-Najjar syndrome
Impaired bilirubin excretion e.g., drug cholestasis, cirrhosis
Extrahepatic obstruction
Classification of jaundice and causes
Prehepatic (UCB)
- Haemolysis: G6PD deficiency, spherocytosis, SCD, blood transfusions (increased risk of pigment gallstones, dark urine due to increased urobilinogen excretion)
- Ineffective erythropoiesis: thalassaemia, pernicious anaemia
- Impaired conjugation: physiologic jaundice of newborn (transient low UGT activity), Gilbert syndrome (low UGT activity but normal liver function, rise in bilirubin with fasting/stress/sickness), Crigler-Najjar syndrome (absent UGT; kernicterus, fatal)
Intrahepatic (UCB 2nd and CB 1st)
- Non-obstructive biliary disease: hepatitis, cirrhosis (inflammation disrupts hepatocytes and small bile ductules), congestive hepatopathy, PBC, CF (dark urine due to increased urine bilirubin), benign recurrent intrahepatic cholestasis
- Obstructive intrahepatic cholestasis (biliary obstruction in liver in bile canaliculi): hepatocellular carcinoma/tumours of liver, intrahepatic gallstones, PSC
Extrahepatic cholestasis/obstructive (obstruction of ducts bw liver and duodenum; CB)
- Choledochilthiasis, inflamamtion e.g., PSC, malformation of biliary tract, pancreatic or bile duct carcinoma, bile duct stricture
Causes of post-operative jaundice
Hypotension, infection, drugs e.g., halothane, cardiac failure, haemolysis, haematoma resorption, bile duct injury/retained gallstone, renal failure, TPN
What kind of virus is HAV
RNA picornavirus
How is HAV transmitted
Faecal-oral route (ingestion of contaminated food or water e.g., shellfish), saliva and rarely via bloodborne products or sexual contact
What is the incubation period of HAV
Short: 2-3 weeks
Clinical features of HAV
Viraemia/prodrome (1-2 weeks): non-specifically unwell, nausea, anorexia, vomiting, malaise, fever, RUQ pain, tender hepatomegaly –> many recover at this stage and remain anicteric
Icteric infection (2 weeks): jaundice, pale stool dark urine, hepatomegaly +/- splenomegaly but viraemia Sx improve
Illness resolves in 3-6 weeks
Rarely severe disease esp. elderly: acute hepatitis, encephalopathy, death
Liver biochemistry in HAV
LFTs
- prodrome: raised ALT, AST (can remain high for weeks –> ~ 6mo)
- icteric: elevated bilirubin, AST, ALT
Serology
- anti-HAV IgM = acute infection
UEC (AKI has been reported in HAV - check)
How is HAV managed?
Notifiable infection and passive and active immunisation of exposed contacts
Supportive Mx
Prevention of HAV
Good hygiene
Killed by boiling water for 10 minutes
Active immunisation = inactivated HAV vaccine given to people traveling to endemic areas, pts with chronic liver disease, those with haemophilia, workers in frequent contact with hepatitis
Passive immunisation = normal human Ig used if recent (< 2 weeks) exposure to HAV (HAV vaccine also given)
What kind of virus is HBV
DNA hepadna virus
How is HBV transmitted
Percutaneous (blood, blood products, saliva), sexual, vertical
Incubation period HBV
Long: 1-5mo
Risk factors for HBV
Multiple sexual partners
MSM
IVDU
Unscreened blood transfusion
Unsterile tattoo/piercing
Born in high prevalence area
Investigations for HBV
Screening:
- HBsAg (active or chronic infection)
- Anti-HBc: if acute HBV suspected Anti-HBc IgM can be requested (acute hepatitis B if high titre, chronic hepatitis B if low titre, IgG suggests past exposure
- Anti-HBs (immunity)
If positive full viral profile and investigations performed
- FBC, LFT, INR, AFP
- Liver USS
- HBeAg (high infectivity/high level infection, persistence implies continued infectious state/development of chronicity)
- Anti-HBe (seroconversion)
- HBV DNA (implies viral replication –> levels indicate response to antiviral Tx)
- APRI/fibroscan to assess for cirrhosis
- HAV, HCV, HDV, HIV
Describe the phases of chronic HBV infection
Immune tolerance (HBeAg positive chronic hepatitis)
- HBeAg +, HBV DNA high, ALT normal (no Tx required)
Immune clearance (HBeAg positive chronic hepatitis)
- HBeAg +, HBV DNA high, ALT high (Tx required)
Immune control (HBeAg negative chronic hepatitis)
- Anti-HBe +, HBV DNA low, ALT normal (no Tx required)
Immune escape (HBeAg negative chronic hepatitis)
- AntiHBe +, HBV DNA high, ALT high (Tx required)
Or immunotolerance (no Tx), HBeAg + chronic hepatitis (Tx), HBeAg - chronic hepatitis (Tx), inactive carrier state (no Tx)
Prevention of HBV vertical transmission
Transmission from a HBeAg + mother to child at parturition is 85%
Vaccination and administration of HBIG to neonate reduces this by 95% but in extremely high viral loads this may be attenuated so in this case the mother should receive tenofovir in the last trimester of pregnancy in addition to neonatal vaccination and HBIG
Prevention of HBV horizontal transmission
Reducing risk of exchange of body fluids
High risk groups should be vaccinated
- MSM
- Adults with multiple sexual partners
- IVDU
- Haemodialysis patients
- Healthcare workers
- Household members of carriers
Which phases of HBV infection can lead to HCC and cirrhosis
Immune clearance and immune-escape/reactivation
Given risk of reactivation in silent carrier state there must be lifelong monitoring
What does reduction in eAg and seroconversion each year imply
Resolution into silent carrier stare or emergence of core promotor/pre-core mutants responsible for severe and progressive hepatitis (monitor ALT, HBV DNA +/- liver biopsy)
What is the HBV serology and histology in an immunotolerant individual
HBsAg +
HBeAg +
Anti-HBc -
Anti-HBs -
Anti-Hbe -
HBV DNA high
ALT normal
Histology normal
What is the HBV serology and histology in a pt with HBeAg + chronic hepatitis B
HBsAg +
HBeAg +
Anti-HBc -
Anti-HBs -
Anti-Hbe -
HBV DNA high
ALT high
Histology hepatitis
What is the HBV serology and histology in a pt with HBeAg - chronic hepatitis B
HBsAg +
HBeAg -
Anti-HBc -
Anti-HBs -
Anti-Hbe +
HBV DNA mildly elevated
ALT high
Histology hepatitis
What is the HBV serology and histology in an inactive carrier
HBsAg +
HBeAg -
Anti-HBc -/+
Anti-HBs -
Anti-Hbe +
HBV DNA low
ALT normal
Histology normal
What is the HBV serology and histology in a resolved infection
HBsAg -
HBeAg -
Anti-HBc +
Anti-HBs +
Anti-Hbe +
HBV DNA 0
ALT normal
Histology normal
What is the HBV serology and histology in a vaccinated pt
HBsAg -
HBeAg -
Anti-HBc -
Anti-HBs +
Anti-Hbe -
HBV DNA 0
ALT normal
Histology normal
How does HBV lead to HCC in absence of cirrhosis
Priming of tumour oncogenes and inactivation of TSGs
What monitoring is required in a HBeAg positive chronic infection (immune tolerance)
6monthly LFTs
6-12monthly HBeAg and antiHBe
12 monthly HBV DNA, liver fibrosis assessment
Periodic review of household contacts and sexual partners
What monitoring is required in a HBeAg negative chronic infection (immune control)
6 monthly LFTs
12 monthly HBV DNA liver fibrosis assessment
What is management for chronic HBV
Entecavir or tenofovir (nucleoside and nucleodtide analogues) or pegylated interferon in women wishing to become pregnant
Notification
Screening of household contacts and administration of HBIG and HBV vaccine
What monitoring is required for pts on HBV treatment (HbeAg - or + chronic hepatitis)
Regular LFTs, UECs, HBV DNA, serum phosphate if on tenofovir
If HBe+: HbeAg, antiHbe
If HBV DNA undetectable: HBsAg, antiHBs
If cirrhotic: FBC, INR
HCC surveillance with 6monthly USS and AFP in certain groups (ATSI, Asian, HDV coinfection, FHx etc)
What kind of virus is HCV
RNA flavivirus
How is HCV transmitted
Percutaneous (blood/blood products e.g., IVDU, unsterile tattoos/piercings, unscreened blood transfusion, needestick injury; saliva), rarely sexual, rarely vertical
HBV acute infection clinical presentation
Varies
- serum-sickness like syndrome (rash, myalgia, fever, arthralgia)
- subclinical hepatitis
- symptomatic hepatitis: fever, rash, myalgia, arthralgia, fatigue, anorexia, N, V, RUQ pain, jaundice
HBV chronic infection clinical presentation
Infection persisting for > 6 mo
- asymptomatic/non-specific Sx
- hepatic failure
- acute hepatitis Sx
Risk factors for HCV infection
IVDU
Blood transfusion without screening
Healthcare workers
Unsterile tattoos
High prevalence areas (Asia, Middle East)
What is cirrhosis?
Irreversible end-point of longstanding liver damage and advanced stage of fibrous tissue accumulation characterised by disruption of normal hepatic parenchyma and diffuse remodelling into perenchymal nodules (regenerated hepatocytes) surrounded by fibrous bands plus microvascular distortion and a variable degree of portosystemic shunting
Causes of cirrhosis
Chronic HBV, HCV
NAFLD
Alcohol liver disease
Autoimmune
MCCs of cirrhosis
Chronic HBV, HCV
NAFLD
Alcoholic liver disease
(but anything causing chronic liver damage e.g., PBC, PSC, autoimmune hepatitis, wilson disease, a1a1 deficiency, Budd-Chiari, congestive hepatopathy with cardiac cirrhosis etc.)
Pathophysiology of cirrhosis
Degeneration and necrosis of hepatocytes –> Kupffer cells activated and destroy hepatocytes and release inflammatory cytokines e.g., TGF-B and PDGF –> activation of normally quiescent stellate cells (beneath endothelial cells lining sinusoids) –> stellate cells produce collagen –> fibrotic bands and regenerative nodules replace parenchyma –> fibrotic tissue compresses hepatic sinusoids and venules –> increased portal vein hydrostatic pressure –> intrasinusoidal HTN and dysfunctional sinusoids –> loss of liver Fx/impaired substrate exchange
Clinical effects of cirrhosis
Portal HTN
- ascites (due to increased HS and reduced oncotic pressure)
- congestive splenomegaly and hypersplenis –> thrombocytopaenia and haemolytic anaemia
- portosystemic shunting (oesophageal and gastric varices, haemorrhoids, caput medusae)
- hepatorenal syndrome
Decreased detoxification
- palmar erythema, spider naevi, testicular atrophy, gynaecomastia, loss of male pattern body hair distribution (excess oestrogen)
- hepatic encephalopathy, asterixis, coma (increased serum ammonia crossing BBB)
- jaundice and pruritus (decreased bilirubin metabolism and no albumin to bind to)
Decreased protein synthesis
- hypoalbuminaemia –> oedema
- coagulopathy (decreased 2, 7, 9, 10)
Reduced vitamin D hydroxylation
What is the Child-Pugh score and what are it’s components
A prognostic grading score to assess the severity of cirrhosis
A: hypoalbuminaemia
B: hyperbilirubinaemia
C: coagulopathy/prolonged INR
D: distension/ascites
E: encephalopathy
What are signs of decompensation in cirrhosis
Jaundice
Hepatic fetor
Asterixis and impaired mentation
What is the life expectancy for different Child-Pugh classes
Child‑Pughclass A: almost normal
Child‑Pughclass B:one-yearsurvival rate ofapprox. 80%
Child‑Pughclass C:one-yearsurvival rate ofapprox. 45%
Score > 7 is candidate for transplant
Causes of hepatic decompensation in cirrhosis
Infection e.g., UTI, cellulitis, SBP, pneumonia, bacteraemia, HAV/HBV/HCV/HDV/CMV/EBV
Metabolic e.g., renal failure, hyponatraemia, uraemia, volume depletion (variceal bleed)
Drugs: alchol, paracetamol, diuretics, opiates
Malignancy: HCC, cholangiocarcinoma, met
Vascular: portal vein thrombosis, Budd-chiari syndrome
Complications of cirrhosis
Ascites
Portal HTN, shunting and variceal bleeding
Encephalopathy
Hepatopulmonary syndrome, portopulmonary syndrome, cirrhotic cardiomyopathy
HCC
Tx of cirrhosis
Tx underlying cause
Alcohol cessation always
Cessation of offending medication
Viral hepatitis Tx if relevant
Mx of autoimmune liver disease/Wilsons disease/haemochromayosis etc.
High energy and high protein diet
Moderate exercise
Correction of nutritional deficiencies esp. vit D and thiamine
Why does ascites occur with liver cirrhosis
Reduced synthesis of albumin = reduced capillary oncotic pressure –> fluid moves out of vessels
Hepatic resistance to blood flow and increased capillary HS pressure -> fluid moves out of vessels
Hepatic resistance to blood flow, splanchnic vasodilation and portosystemic shunt formation –> release of systemic vasodilators –> RAAS –> increased fluid retention (secondary to sodium)
When new-onset ascites in cirrhotic pt is detected what Ix should be done?
Paracentesis for
- measurement of serum ascites to albumin gradient (SAAG): if > 11g/L ascites is almost always due to portal HTN
- MC&S
- cytology
- protein
- LDH
How is ascites in cirrhosis Mx
No added sodium diet
Diuretics e.g., spironolactone 100mg + furosemide 40mg
Regular weight and serum biochemistry checks
Refractory
- Large volume paracentesis
- Transjugular intrahepatic portosystemic shunting
- Liver transplant
Complications of diuretic use in cirrhosis
Hepatic encephalopathy
Renal impairment
Hypotension
Electrolyte imbalance
Explain how a large volume paracentesis is performed in cirrhotic ascites
Can be done outpatient
For every L of ascites removed give IV 8g albumin to prevent orthostatic hypotension and renal failure from fluid shifts
What are the risks of TIPS
Hepatic encephalopathy
Shunt-induced congestive cardiac failure (pt must have echo to ensure LEF > 60% before TIPS)
What is hepatorenal syndrome?
A marker of decompensated cirrhosis requiring the presence of ascites and characterised by rising creatinine in absence of other causes of renal failure
Compare type 1 and type 2 HRS
- rapidly progressive reduction of renal Fx (doubling of creatinine in < 2 weeks) characterised by acute kidney injury (median survival 2 weeks)
- moderate renal failure with steady/slowly progressive course characterised by refractory ascites (median survival 4-6mo)
MC precipitants of HRS
bacterial infection esp. SBP, GI bleed, paracentesis
Management of hepatorenal syndrome
Exclude renal parenchymal disease/obstruction/other causes
Septic screen including paracentesis
Discontinue diuretics
Volume expansion
Tx infection/precipitant
Avoid nephrotoxins
Vasoconstrictors: splanchnic and systemic vasoconstriction allows for improved renal perfusion
- e.g., terlipressin (ADH analogue) or midodrine (noradrenaline) with somatostatin/octreotide
Albumin infusion with terlipressin improves efficacy
Liver transplant must be considered
How does HRS occur
Hepatic resistance to blood flow and portosystemic shunting –> systemic vasodilation –> RAAS & sympathetic NS activation –> sodium and water retention –> progressive renal vasoconstriction
What is the risk of reversing hyponatraemia too quickly
Osmotic demyelination syndrom
How does hyponatraemia occur in cirrhosis
Impaired free water excretion from increased ADH
What is spontaneous bacterial peritonitis
Infection of ascitic fluid in absence of any focal intra-abdominal, surgically treatable source of infection
Clinical presentation of sponatenous bacterial peritonitis in cirrhosis
MC: deteriorating liver Fx, encephalopathy, renal failure, or shock
Less common: abdo pain, peritonism
Possibly asymptomatic
When should a diagnostic tap/paracentesis looking for SBP need to be performed?
At first episode of ascites and every subsequent presentation in which person with ascites has deteriorated
How is spontaneous bacterial peritonitis Dx
Ascitic fluid analysis: 1 of
- High neutrophil count
How is spontaneous bacterial peritonitis Dx
Ascitic fluid analysis: 1 of
- High neutrophil count
How is spontaneous bacterial peritonitis Dx
Ascitic fluid analysis: 1 of
- High neutrophil count
How is spontaneous bacterial peritonitis Dx
Ascitic fluid analysis: 1 of
- High neutrophil count
How is spontaneous bacterial peritonitis Dx
Ascitic fluid analysis: 1 of
- High neutrophil count
How is spontaneous bacterial peritonitis Dx
Ascitic fluid analysis: 1 of
- High neutrophil count
- High WCC
- Positive culture
What organisms are most commonly implicated in SBP
GNRs esp. escherichia coli
Streptococci esp. enterococcus
When is a secondary cause of peritonitis e.g., bowel perforation more likely than SBP
Polymicrobial culture
Localising peritoneal signs
Treatment of spontaneous bacterial peritonitis
Empirical: IV ceftriaxone 2g daily or cefotaxime 2g 8 hourly
If kidney impairment or high risk of HRS give albumin infusion
If pt not improving repeat paracentesis after 2 days and if neutrophil count has not dropped to 25% of original suspect resistant organism and change antibiotics
Prevention of spontaneous bacterial peritonitis in patients with cirrhosis
Secondary antibiotic prophylaxis after first episode: trimethoprim + sulfamethoxazole 160 + 800mg PO daily
Primary prophylaxis is only recommended in high risk patients: cirrhosis, ascites, low ascites fluid protein concentration and either impaired kidney function or liver failure score 9+
When is variceal bleeding a risk
When portal HTN is > 12mmHg and portosystemic shunts have formed but cannot facilitate the high pressure flow
How does portal HTNive gastropathy tend to present
IDA rather than obvious GI haemorrhage
What is endoscopic feature that suggests high risk of variceal bleed
Red-wale sign = red streak over varix suggesting recent bleeding
Bleeding
Fibrin clot
What is primary prophylaxis for variceal bleeding
Pts with large varices should be given beta-blockers e.g., propranalol (or carvedilol)
Endoscopic prophylaxis may also be attempted (band-ligation) in high risk varices
When should patients with liver disease have an upper endoscopy
All patients with definite/suspected cirrhosis to look for oesophageal varices
Repeat every 2 years if normal
Repeat in 1 year if low risk varices
Give propranolol and/or endoscopic band ligation if high risk varices
Management of variceal bleeding
Resuscitation and supportive care
Blood transfusion
Manage coagulopathy and thrombocytopaenia
Terlipressin/somatostatin analogue e.g., ocretotide
Prophylactic ABx e.g., ceftriaxone
Endoscopy –> band ligation, clipping, balloon tamponade
TIPS
Mx alcohol withdrawal and comorbid conditions
Propranolol
MC complications after variceal haemorrhage
Sepsis
AKI
Hepatic encephalopathy
Management of portal HTNive gastropathy
Propranolol –> TIPS if propranolol ineffective
What is hepatic encephalopathy and how does it occur
The neurological and psychiatric dysfunction/deterioration in mental status and cognitive function that occurs in individuals with significant hepatic dysfunction and portosystemic shunts due to inadequate elimination of metabolic products and accumulation of neurotoxic metabolites like ammonia that can cross BBB.
Precipitants of hepatic encephalopathy
Volume depletion (often from diuretics –> correct with IV albumin and stop diuretics)
Infection (treat with ABx)
Renal failure and electrolyte imbalance (correct)
Alcohol (cease and Mx withdrawal)
Sedatives (cease)
TIPS (lactulose or rifaximin)
Hepatocellular carcinoma
Protein load including GI bleed (endoscopy and Mx of bleed)
Constipation (lactulose)
How do lactulose and rifaximin work in hepatic encephalopathy
Lactulose is converted to lactic acid by intestinal flora and as the gut is acidified ammonia is converted to ammonium which is excreted in faeces
Rifaximin reduces the number of ammonia producing bacteria in gut
Clinical features of hepatic encephalopathy
Fatigue, lethargy, apathy
Altered consciousness: mild confusion –> stupor –> coma
Disorientation, irritability
Memory loss
Impaired sleeping pattern
Inappropriate behaviour
Slurred speech
Asterixis