PATHOPHYSIOLOGY -The liver.

1. PATHOPHYSIOLOGY-The liver. Anne Aspin 2010

2. Bile. • Thick greenish yellow fluid secreted by liver cells. • Alkaline. • Emulsifies fats in the intestine. • It stimulates peristalsis in the intestine, acts as a natural aperient. • Deodorant in faeces.

3. During fetal life, placenta is the principal route to eliminate unconjugated bilirubin. • In newborn infants hepatic cells excrete conjugated water soluble bilirubin into biliary system and gastro intestinal tract

4. A guide to the liver. • Located behind lower ribs on the right side of the abdomen. • An adult- size of a rugby ball. • 300 billion specialised cells- well organised intricate system of bile ducts and blood vessels.

5. The little bile ducts drain every bile cell and join together like tributaries entering a stream to form one main duct from each lobe. • The two ducts join to form the common hepatic duct, this joins the duct from the gall bladder (cystic duct), to form the common bile duct. This joins the small intestine through the Ampulla of Vater.

6. The gall bladder and its ducts.

7. Blood supply to and from the liver. • Hepatic artery- which divides into fine branches –to the fine bile ducts. • Portal vein carries nutrients from the stomach and intestine to the liver (also from spleen). • Portal vein divides into fine branches- into sinusoids. • Blood leaves sinusoids via hepatic vein to heart.

8. Functions of the liver. • Breaks down fat to produce energy. • Amino acids broken down to form urea. • Detoxicate drugs. • Vit A synthesized to carotene. • Liver main heat producing organ. • Plasma proteins synthesized. • Tissue cells broken down – uric acid and urea. • Carbohydrate converted to fat for storage.

9. Functions (cont) • Prothrombin and fibrinogen synthesized from amino acids. • Antibodies and antitoxins are manufactured. • Heparin is manufactured. • Stores: Vit A and D, anti anaemic factor, iron from diet, glucose stored as glycogen and back to glucose in the presence of insulin. • Bile is formed.

10. Guess which one was on TPN?.

11. Extremely Low Birth Weight Infant • Less than 1000g, less than 27/40 • Susceptible to all complications of prematurity • Thermoregulation – high surface area to body weight • Hypoglycaemia – stress and low glycogen stores

12. ELBW • Fluids and electrolytes – PDA,IVH,CLD,BPD Compromised renal function – decreased GFR – decreased ability to reabsorb bicarbonate – inability to concentrate urine

13. Nutrition • High energy requirements for growth • Heat loss raises energy need • Trophic feeding stimulates gastro-intestinal tract and prevent mucosal atrophy • Prolonged TPN may result in cholestasis and elevated triglyceride levels. • Breast milk

14. Hyperbilirubinaemia • Increased production of bilirubin transfusion, infection • Decreased activity of transferase enzyme due to hypoxia,infection,hypothermia or thyroid deficiency

15. Hyperbilirubinaemia (cont) • Block of transferase enzymes (drugs) • Decreased enzyme- prematurity • Decreased bilirubin uptake by liver cells

16. Kernicterus • Occurs when unconjugated bili crosses blood-brain barrier staining basal ganglia, pons and cerebellum • Those who do not die with kernicterus are deaf, mental retardation and cerebral palsy

17. Phototherapy • Decreases unconjugated bilirubin levels • Breaks down so water soluble, so can be easily excreted

18. Hepatic complications in preterm babies on TPN • Cholestasis 7.4% - 84% • 1st reported 1971 – baby 71days old, cholestasis, bile duct proliferation, early cirrhosis • Early feeding reduces above • Increased biochemical test results of damage, function and excretion

19. Prevention • Early enteral feeding • Prevention of sepsis • Cycling TPN • Mucus fistula re-feeding • Ursodeoxycholic acid

20. Differential diagnosis • Jaundice birth-24hrs • Sepsis • Haemorrhage • Cytomegalovirus • Rubella • Congenital toxoplasmosis

21. Jaundice day 2-3 • Physiological jaundice • Criggler Najjar syndrome

22. Jaundice after day 3 • Septicaemia • Syphillis • Toxoplasmosis • Cytomegalovirus

23. Jaundice after one week • Breast milk • Septicaemia • Congenital atresia of ducts • Hepatitis • Rubella • Herpes • Galactosaemia • Hypothermia • Haemolytic disease

24. Jaundice after one month • Inssipated bile syndrome • TPN related cholestasis • Cytomegalovirus • Syphillis • Toxoplasmosis

25. Biliary atresia.

26. What is biliary atresia?. • Inflammation develops within bile ducts around time of birth, either within ducts inside or outside of the liver. • Bile ducts outside liver – irreversible damage preventing bile flow.

27. Signs of biliary atresia. • Seem well, but white of the eyes are yellow, yellowing of the skin. • Yellow coloured urine. • Pale stools. • Bleeding –prolonged.

28. Investigations. • Haematological and liver function tests. • Screening for infection and metabolic causes. • Ultrasound examination. • Radionuclide studies. • Percutaneous liver biopsy.

29. Always look for yellow pooh!!!

30. Treatment. • Surgical operation called a Kasai procedure. • Major surgery, very sick babies.

31. Extrahepatic biliary atresia. • The blocked duct is removed. • A single open duct is then joined to a loop of intestine. Hepaticojejunostomy.

32. Post operation. • IV fluids. • Pain relief. • Antibiotics. • Parents. • Medications regime.

33. Medications. • IV antibiotics –to reduce risk of cholangitis. • Vitamins A,D,E,K - due to poor bile flow which reduces absorption of dietary fat soluble vits. • Phenobarbitone – given to increase bile flow. • Questran – improves liver function and removes substances which cause the skin to itch.

34. Medications (cont) • Spironalactone – excretion of excess fluid which otherwise collects in the abdomen. • Ursodeoxycholic acid – promotes the flow of bile. • Ranitidine – reduces stress induced stomach irritation.

35. Some complications may occur. • Cholangitis • Ascites • Low albumins • Portal hypertension • Itching

36. Cholangitis. • An infection of the bile ducts resulting in inflammation. • Pyrexia • Increasing jaundice • Further liver damage • IV antibiotics.

37. Ascites • An abnormal collection of fluid in the abdomen around the organs. • May be associated with general oedema. • Protruding abdomen • Shiny, tense • Prominent veins • Rapid weight gain • Shortness of breath • Reduced appetite.

38. Complications of ascites • Failure to thrive and vomiting • Infection • Restricted movement • Breathing difficulties.

39. Albumins. • If ascites persists, disease process has affected the livers ability to make albumin. • Diet will be assessed to reduce fluid and salt intake. • 20% Albumin infusion.

40. Portal hypertension. • High blood pressure in the portal vein, the main vein carrying blood from the gut to the liver. • Occurs due to scarring in the liver which causes back pressure in the portal vein. • This causes veins like varicose veins to develop in the lining of the oesophagus, stomach or intestine.

41. Portal hypertension • Blockage of portal vein –thrombus. • Scarring in the liver • Increased resistance to blood leaving the liver, due to obstruction or heart disease.

42. Portal hypertension (cont) • Enlarged spleen – from back pressure, effects breakdown of RBC as new are made, when spleen enlarged it removes more than it should – effects platelets needed for blood clotting. • Ascites –from back pressure on blood vessels –forces fluid to leak out to around surrounding organs. • Prominent veins over abdomen.

43. Portal hypertension (cont) • Varices, also known as collaterals. Thin walled and can bleed. • Bleeding causing tiredness, breathlessness, pale appearance. Present in vomit or stools. • Diarrhoea, poor weight gain –the blood vessels in the lining of the intestine swell as blood flows under pressure, reduces absorption of digested food.

44. Pruritis/itching. • Occurs with poor bile flow. • Excessive amounts of bile acids. • From mild , intermittent or severe. • Palms, soles of feet, extremeties and trunk. • Medications for treatment.

45. Pruritis/itching (cont) • Questran/ cholestyramine. Combines with bile acids in the small intestine and reduces reabsorption. • Phenobarbitone –helps liver to excrete the substances thought to induce itching. • Rifampicin –significant relief from itching by reducing harmful bile acids but increases the amount of protective acids. • Sedatives –Vallergan. • Ursodeoxycholic acid –increases watery bile salts to aid secretion.

46. Choledochal cyst. • Chole – relating to bile • Dochal – containing or receiving • Cyst – fluid collection • Affects ducts outside liver. Bile collects inside dilated ducts – flow of bile impaired. • Caused by ?malformation of bile duct inutero.

47. Types of choledochal cyst. • 1:50,000 • 3 x girls than boys • These two types cause pancreatitis.

48. Other types of choledochal cysts.

49. Signs and symptoms • Jaundice, • Persistant or intermittent. • Pale stools and dark urine • Intermittent abdominal pain. • Cholangitis, causing rigors. • Peritonitis, if the cyst bursts or leaks. • An abdominal swelling

50. Roux loop.