Gastroenterology Flashcards
Unconjugated billirubin presentation and causes?
Unconjugated bilirubin is not water soluble, so it is not excreted in the urine and the urine remains a normal colour.
prehepatic: Gilberts and Haemolytic anaemia
Hepatic jaundice presentation?
uptake, conjugation and excretion are all impaired leading to a rise in both conjugated and unconjugated bilirubin
Excretion is usually the rate limiting step and impaired to the the greatest extent
leads to an excess of conjugated bilirubin that is returned to the blood stream and is excreted in the urine giving it a dark colour
Post hepatic jaundice - cause?
a physical block e.g. a gallstone so there there is no urobilinogen or sterocobilinogen
This means stool is pale. The kidneys filter excess conjugated bilirubin still gives the urine a dark colour
Direct Coombs test?
used to detect the presence of antibodies bound to the surface of RBCs
It is used to detect immune haemolytic anaemia
e.g. on fetal blood to diagnose HDN
Indirect Coombs test?
Indirect coomb’s test is used to detect antibody in patient serum
Used in transfusion
Also e.g. to screen women for antibodies that may cause HDFN
Hepatic causes of jaundice?
V: Ischaemic hepatitis
I: Viral hepatitis
T: Alcohol
A: PBC, PSC, autoimmune hepatitis
M: Haemochromatosis, Wilson’s disease
I: Drug induced e.g paracetamol toxicity
N: Hepatocellular carcinoma
Sickle cells are pathogonimic of sickle cell disease
Schistocytes: fragments of blood cells: heart valves (sheering forces) , HUS, TTP, microangiopathic haemolytic anaemia
Reticulocytes: immature RBCs not biconcave
Stomatocytes: stomatocytosis can be congenital (e.g. xerocytosis) or acquired (typically due to excessive alcohol consumption) -> haemolytic anaemia as fragile
Paracetamol overdose treatment?
NAC:
If plasma-paracetamol concentration falls on or above the treatment line on the paracetamol treatment graph
who present within 8 hours of ingestion of more than 150 mg/kg of paracetamol if there is going to be a delay of 8 hours or more in obtaining the paracetamol concentration after the overdose
who present 8–24 hours after ingestion of an acute overdose of more than 150 mg/kg of paracetamol even if the plasma-paracetamol concentration is not yet available
who present more than 24 hours after ingestion of an overdose if they are clearly jaundiced or have hepatic tenderness, their ALT is above the upper limit of normal (patients with chronically elevated ALT should be discussed with the National Poisons Information Service), their INR is greater than 1.3 (in the absence of another cause), or the paracetamol concentration is detectable.
Not if they are toenail
Steatohepatitis: Inflammatory infiltrate
Mallory Denk bodies which indicate alcoholic liver disease, these are cytoplasmic inclusions
Steatosis: multiple round empty vacuoles in the cytoplasm
Cirrhosis: fibrous bands, separating regenerative nodules
UC histology?
Macroscopic: pseudopolyps (scar tissue from repetitive ulceration), red, indurated irregular surface
Increased cellular density: inflammatory infiltrates, crypt abscesses, architectural distortion, loss of goblet cells
Inflammation does not spread beyond the mucosa
