GI: Pancreas, Liver & Gallbladder Disease Flashcards
Describe red cell breakdown.
- 120 days
- Occurs extravascularly in macrophages in spleen and liver
- Bilirubin released by heme breakdown. It is hydrophobic and therefore bound to albumin before being carried to the liver
- Bilirubin conjugated with glucoronic acid by UDP glucoronyl transferase
- Conjuaged bilirubin is water soluble and secreted by hepatocyte into bile canaculi
Describe bilirubin transport?
- Conjuagted bilirubin is converted to urobiligoen in the intestine and kidney
- In the intestine urobilinogen is converted to stercobilin
- In the kidneys urobilinogen is converted to urobilin which is light yellow
How do we measure liver dysfunction?
- Failure of anabolism (albumin, glycogen, numerous coagulation factors, Haematopoiesis in fetus)
- Failure to catabolise and excrete (drugs, hormones, haemaglobin, poisons, can take over removal of aged red cells after splenectomy)
- Markers of hepatocyte damage
What is the results of failure of anabolism?
- Prolonged prothrombin time (inr)
- Signifies serious liver damage
- Hypoalbuminaemia reflects severe liver dysfunction
- Signs of severe liver damage
What is pre-hepatic jaundice?
-Too much bilirubin
Caused by haemolytic anaemia for example
What is intra-hepatic jaundice?
-Failure of hepatocytes to conjugate and/or secrete most of the bilirubin presented to them. Stasis within the liver is called cholestasis.
Caused by hepatitis, cirrhosis for example
What is post-hepatic jaundice?
-Failure of the biliary tree to convert the conjugated bilirubin to the duodenum.
Caused by biliary tree obstruction such as gallstones or carcinoma of the head of pancreas
What is result of increased serum levels of conjugated bilirubin?
-Water soluble so will be excreted in the urine and turn the urine dark yellow. Can be measured with a dipstick
What is the result of increased level of urobilinogen?
Will not noticeable colour the urine but can be measured with a dipstick
Why does pruritus occur in post-hepatic jaundice?
-Inability to secrete bile salts leading to itching
What are the signs of pre-hepatic jaundice?
- Dark stools
- Normal urine colour
- Mild jaundice
- No prurities
What are the signs of intra-hepatic jaundice?
- Moderate jaundice
- Stools normal
- Urine is dark
- No pruritus usually
What are features of post-hepatic jaundice?
- Raised serum bilirubin
- Decreased urinary urobiliogen
- Conjuagted bilirubin present in urine
What are features of intra-hepatic jaundice?
- Raised serum biliruibin
- Normal urinary urobiliogen
- Conjugated bilirubin present in urine
What are features of pre-hepatic jaundice?
- Raised serum bilirubin
- Increased urinary urobiliogen
- No conjugated bilirubin present in urine
What are signs of post-hepatic jaundice?
- Severe jaundice
- Stools pale
- Urine is dark
- Pruritis
What are markers of liver damage?
- ALT
- AST
- Alk Phos
- Gamma GT (alcohol induced so can indicate alcoholism)
What are the causes of increased Alk Phos?
Bone disease
- Bone metastases
- Bone fracture
- Osteomalacia
- Hyperparathyroidism
- Paget’s disease of bone
Liver disease with cholestasis
- Biliary obstruction
- Cirrhosis
- Liver metastases
- Drugs
*Normally high in growing bone
What are causes of Raised ALT?
Hepatitis
- Viral
- Acute alcohol intake
- Fatty liver disease
- Drugs/toxins
What are causes of raised Gamma GT?
- Biliary duct obstruction
- Cirrhosis
- Liver metastases
- Drugs
- Alcoholism
What are common liver and bile duct disease?
- Hepatitis
- Cirrhosis
- Gallstones and biliary tract obstruction
- Liver metastases
What is pathology underlying hepatitis?
-Inflamed and/or necrotic hepatocytes that cannot function normally
What are the implications of liver failure?
- Increased susceptibility to infections (bacterial mostly)
- Increases susceptilibit to toxins and drugs
- Increased blood ammonia due to failure to clear ammonia via urea cycle
- Ammonia is produced by colonic bacteria and deamination of amino acids. this can causes hepatic encephalopathy
What are symptoms of hepatitis?
- Feeling generally unwell
- Anorexia
- Fever
- Right upper quadrant pain
- Dark urine
- Jaundice
What are typical blood test findings in acute hepatitis?
- Normal albumin and INR
- High serum bilirubin
- Conjugated bilirubin present in the urine
- Very high serum ALT
- Normal/Silghtly raised Alk Phos
- Normal/Silghtly raised Gamma GT
What is liver cirrhosis and causes?
-Liver fibrosis producing a shrunken hard nodular liver
Caused by alcohol, Viral hepatitis, Fatty liver disease and Idiopathic
What are the effects of liver fibrosis?
- Pressure and occlusion of the hepatic sinusoids leads to portal hypertension which leads to portosystemic shunting, including oesophageal varices, diverting nutrient-carrying blood away from the liver.
- Pressure on the bile canaliculi and therefore reduced ability to excrete toxins, bilirubin.
- Replacement of hepatocytes by fibrous tissue which leads to reduced albumin and clotting factor production
What are the sites of portosystemic anastomoses?
- Anorectal juction
- Ligamentum teres of falciform ligament
- Oesophagogastric junction
What are symptoms of cirrhosis?
- Fatigue/Weakness
- Bleeding and bruising early
- Swollen abdomen
- Swollen legs
- Weight loss
- Jaundice
- Haematemesis and/or malena
- Confusion, drowsiness and slurred speech
How can cirrhosis be treated?
- Not possible to reverse
- Treatment aimed at dealing with complications
- Only cure is liver transplantation
What is cholangitis?
Life threatening complication of bile duct obstruction as a result of infection in the bile ducts. Commonest bacteria is E.Coli
-Obstruction is common due to to gall stones in common bile duct
What is a biliary colic?
- Not a true colic. Pain is constant
- Pain in the right upper quadrant that radiates to the tip of the right scapula/shoulder due to irritation of diaphragm
- Often precipitated by eating a fatty meal and can last up to 6 hours
What is acute cholecystitis?
- Gallstone obstructs the cystic duct then there is stasis of the gallbladder contents which is an infection risk
- Infecting organism is E.Coli
What are the symptoms of acute cholecystitis?
- Severe gall bladder pain
- Systemically unwell and toxic
- Pyrexial
- Tender over gall bladder
What is acute pancreatitis?
-Premature activation of pancreatic proteases in the pancreas itself rather than the duodenum. Protease then auto digest the pancreases and retroperitoneum
What is chronic pancreatitis?
- Rare and due to repeated low grade pancreatitis that causes pancreatic fibrosis.
- Due to alcohol abuse
- Pancreas become calcified and patients suffer severe epigastric and back pain that leads to opiate addiction and not infrequently suicide.
What is the aetiology of acute pancreatitis?
- Alcohol alters the balance between proteolytic enzymes and protease inhibitors thus triggering enzyme activation, auto digestion and cell destruction
- Gallstones blocking the ampulla of vater lead to outflow obstruction with pancreatic duct hypertension and a toxic effect of bile salts contribute to activation of pancreatic proteases.
What are symptoms of acute pancreatitis?
- Epigastric pain that goes through the back
- Vomiting
- Dehydration
How is acute pancreatitis diagnosed and treated?
Investigations
- Raised serum amylase or serum lipase
- CT scan may be used in moderate/severe cases to look for pancreatic necrosis/pseudocyst. Necrosed pancreas is non-enhancing with contrast
Treatment of acute pancreatitis
- No specific treatment
- Analgesis, supportive treatment
- Fluid resuscitation as patient can sequester litres of fluid in their retropeiritoneum
What is clinical presentation of pancreas cancer?
- Anorexia, Malaise, Fatigue
- Significant weight loss
- Epigastric and/or back pain
- Dark urine
- Pale Stools
- Pruritis
