Gastroenterology Flashcards
Causes of increased ALP
Increased in bile duct obstruction
What is ALP and where is it distributed in the body
Alkaline Phosphatase
High levels in cell membranes of:
- Biliary tree
- intestine
- placenta
- bone
- renal tubular cells
“Plate of Liver and Kidney beans”
(N.B. low levels in liver)
Hepatitis picture of LFTs
High transaminases (AST / ALT) with proportionally less of a rise in ALP
Criteria for Acute Liver failure
- Increase in PT (by 4-6 seconds) - INR >1.5
- Development of hepatic encephalopathy
- WITHOUT pre-existing cirrhosis & illness for > 6 months
What is GGT
Gamma-glutamyl transpeptidase
Enzyme found around body but particularly in the liver (primarily biliary epithelium)
Increased in bile duct obstruction
Causes of metabolic alkalosis
Vomiting / aspiration
Diuretics
Hypokalaemia
Primary hyperaldosteronism (Conn’s syndrome)
Cushing’s syndrome
Biochem disturbance from prolonged vomiting
Metabolic alkalosis + hypokalaemia
Why does vomiting cause hypokalaemia and metabolic acidosis?
Large amounts of hydrochloric acid are lost –> loss of H+ ions and fluid
Fluid loss –> activation of the renin-angiotensin-aldosterone system (RAAS) due to reduced renal perfusion –> increased aldosterone secretion.
Aldosterone promotes the reabsorption of Na+ in exchange for H+ and K+ in the kidneys.
In general, where Na+ goes, water follows, meaning the blood volume is increased, however, more potassium and H+ are lost, leading to hypokalaemic metabolic alkalosis
Prolonged diarrhoea ABG
hypokalaemia
hypovolaemic shock
metabolic acidosis (due to the loss of bicarbonate ions from the gut)
What is Primary sclerosing cholangitis?
biliary disease of unknown aetiology characterised by inflammation and fibrosis of intra and extra-hepatic bile ducts
What condition is primary sclerosing cholangitis associated with ?
Ulcerative colitis
8% of people with UC have PSC
80% of people with PSC have UC
(also Crohns and HIV but a lot less common)
What is primary sclerosing cholangitis?
intrahepatic or extrahepatic ducts become strictured and fibrotic
Hepatic consequence of primary sclerosing cholangitis
Chronic bile obstruction eventually leads to liver inflammation (hepatitis), fibrosis and cirrhosis.
Presentation of Primary sclerosing cholangitis
Jaundice
Chronic right upper quadrant pain
Pruritus
Fatigue
Hepatomegaly
Signs of cirrhosis if they have developed this
LFTs “cholestatic picture”
ALP = most derranged LFT and may be the only abnormality at first
May be a rise in bilirubin as strictures become more severe and prevents bilirubin from being excreted through the bile duct
Other LFTs (i.e. transaminases: ALT and AST) can also be deranged, particularly as the disease progresses to hepatitis.
Role of autoantibodies in primary sclerosing cholangitis
Not helpful in diagnosis (Not specific/sensitive)
Can indicate where there is autoimmune element –> may respond to immunosuppression
- p-ANCA - in up to 94%
- Antinuclear antibodies (ANA) - in up to 77%
- Anticardiolipin antibodies (aCL) in up to 63%
What is an MRCP and what is it used for?
MRI of Liver, bile ducts and pancreas
Diagnosis of:
- PSC
-
Fat soluble vitamins
Vitamins A, D, E, and K
(Amelia Doesnt Even Know)
Management of primary sclerosing cholangitis
- Only definitive = liver transplant
- ERCP - stents to open strictures
- Ursodeoxycholic acid - may slow progression of disease
- Colestyramine - bile acid sequestrate in that it binds to bile acids to prevent absorption in the gut and can help with pruritus due to raised bile acids
Where foes ECRP scope pass through from GI tract –> biliary system
sphincter of Oddi and into the ampulla of Vater
“Beads on a string” appearance of bile ducts
Primary sclerosing cholangitis
What is Primary Biliary Cirrhosis?
Chronic, progressive, autoimmune condition leading to destruction of intrahepatic ducts
The first parts to be affected are the intralobar ducts, also known as the Canals of Hering. This causes obstruction of the outflow of bile, which is called cholestasis. The back-pressure of the bile obstruction and the overall disease process ultimately leads to fibrosis, cirrhosis and liver failure.
Which conditon is autoimmune out of PBC and PSC ?
Primary Biliary Cirrhosis
Conditions associated with Primary Biliary Cirrhosis?
Coeliac disease
Thyroiditis
Middle aged women
Rheumatoid conditions (e.g. systemic sclerosis, Sjogrens and rheumatoid arthritis)
Autoantibodies associated with primary biliary cirrhosis?
Anti-mitochondrial antibodies
- most specific to PBC, part of the diagnostic criteria)
Anti-nuclear antibodies (35% of patients)
Ursodeoxycholic acid role
used in the management and treatment of cholestatic liver disease
Treatment of primary biliary cirrhosis
Ursodeoxycholic acid (better response to this compared to PSC)
Colestyramine - symptomatic management of itching
Immunosuppresants (some patients)
What is aminosalicylates (e.g. mesalazine) used for?
To control inflammation in GI tract
Used in Ulcerative colitis
I) Inducing remission in mild to moderate disease
II) Maintaining remission
Treatment of Severe flare of UC
Admit + IV hydrocortisone
Treatment of flare of Crohns
Steroids (e.g. oral prednisolone or IV hydrocortisone)
If steroids don’t help, consider immunosuppression:
Azathioprine
Methotrexate
Effect of smoking on IBD ?
Crohns - smoking increases risk
UC - smoking decreases risk
Effect of smoking on IBD ?
Crohns - smoking increases risk
UC - smoking decreases risk
Severe disease criteria IBD
if >= 6 bowel movments per day PLUS at least 1 feature of systemic upset
Other features:
Blood in stool clearly visible
Pyrexia
HR >90 bpm
Anaemia
ESR >30
(Trulove & Witts’ criteria)
Which IBD has tenesmus
UC
Rome IV criteria for IBS
Recurrent abdo pain at least one day/week over the past three months (with symptom onset at least six months ago)
and two of the following:
1. It is related to defecation and/or
2. it is associated with a change in stool frequency, and/or
3. It is associated with a change in stool appearance.
What is Charcot’s triad?
Suggestive of ascending cholangitis (bacterial infection of the biliary tree - typically E.Coli)
- Fever
- Jaundice
- Right upper quadrant pain
What is Reynold’s pentad?
Suggestive of severe ascending cholangitis
= Charcot’s triad + hypotension and confusion
SO
1. Fever
2. Jaundice
3. Right upper quadrant pain
4. Hypotension
5. Confusion
Management of ascending cholangitis
- IV antibiotics
- ERCP after 24-48 hours to relieve any obstruction
Key differentiating features between chronic liver disease and acute failure
In acute but not chronic
- Prothombin time raised
- Very high bilirubin
- presence of encephalopathy
Causes of acute liver failure
Paracetamol overdose
Alcohol
Viral hepatitis (A & B)
Acute fatty liver of pregnancy
Pancreatitis scoring system
P - PaO2 <8kPa
A - Age >55-years-old
N - Neutrophilia: WCC >15x10(9)/L
C - Calcium <2 mmol/L
R - Renal function: Urea >16 mmol/L
E - Enzymes: LDH >600iu/L; AST >200iu/L
A - Albumin <32g/L (serum)
S - Sugar: blood glucose >10 mmol/L
