jaundice and complications of ascites pptx - د.محمد عبد الله

Jaundice

• Jaundice is usually detectable clinically when the plasma bilirubin exceeds 2.5 mg/dL.

Jaundice

Pre-hepatic jaundice
Hepatocellular jaundice
Obstructive jaundice

Pre-hepatic jaundice

This is caused either by haemolysis or by congenital hyperbilirubinaemia, and is characterised by an isolated raised bilirubin level.
In haemolysis, destruction of red blood cells or their marrow precursors causes increased bilirubin production. Jaundice due to haemolysis is usually mild because a healthy liver can excrete a bilirubin load six times greater than normal before unconjugated bilirubin accumulates in the plasma. This does not apply to newborns, who have less capacity to metabolise bilirubin.
The most common form of non-haemolytic hyperbilirubinaemia is Gilbert’s syndrome, an inherited disorder of bilirubin metabolism. Other inherited disorders of bilirubin metabolism are very rare.

Hepatocellular jaundice
Hepatocellular jaundice results from an inability of the liver to transport bilirubin into the bile, occurring as a consequence of parenchymal disease. Bilirubin transport across the hepatocytes may be impaired at any point between uptake of unconjugated bilirubin into the cells and transport of conjugated bilirubin into the canaliculi. In addition, swelling of cells and oedema resulting from the disease itself may cause obstruction of the biliary canaliculi. In hepatocellular jaundice the concentrations of both unconjugated and conjugated bilirubin in the blood increase. Hepatocellular jaundice can be due to acute or chronic injury, and clinical features of acute or chronic liver disease may be detected clinically. Characteristically, jaundice due to parenchymal liver disease is associated with increases in transaminases (AST, ALT), but increases in other LFTs, including cholestatic enzymes (GGT, ALP) may occur, and suggest specific aetiologies. Acute jaundice in the presence of an ALT of greater than 1000 U/L is highly suggestive of an infectious cause (e.g. hepatitis A, B), drugs (e.g. paracetamol) or hepatic ischaemia. Imaging is essential, in particular to identify features suggestive of cirrhosis, to define the patency of the hepatic vasculature, and to obtain evidence of portal hypertension. Liver biopsy has an important role in defining the aetiology of hepatocellular jaundice and the extent of liver injury.

Obstructive (cholestatic) jaundice

Cholestatic jaundice may be caused by:
• failure of hepatocytes to initiate bile flow
• obstruction of the bile ducts or portal tracts
obstruction of bile flow in the extrahepatic bile ducts between the porta hepatis and the papilla of Vater. In the absence of treatment, cholestatic jaundice tends to become progressively more severe because conjugated bilirubin is unable to enter the bile canaliculi and passes back into the blood, and also because there is a failure of clearance of unconjugated bilirubin arriving at the liver cells. Cholestasis may result from defects at more than one of these levels. Those confined to the extrahepatic bile ducts may be amenable to surgical or endoscopic correction.

• Clinical features comprise those due to cholestasis itself, those due to secondary infection (cholangitis) and those of the underlying condition. Obstruction of the bile duct drainage due to blockage of the extrahepatic biliary tree is characteristically associated with pale stools and dark urine. Pruritus may be a dominant feature and can be accompanied by skin excoriations. Peripheral stigmata of chronic liver disease are absent. If the gallbladder is palpable, the jaundice is unlikely to be caused by biliary obstruction due to gallstones, probably because a chronically inflamed stone-containing gallbladder cannot readily dilate. This is Courvoisier’s Law, and suggests that jaundice is due to a malignant biliary obstruction (e.g. pancreatic cancer). Cholangitis is characterised by ‘Charcot’s triad’ of jaundice, right upper quadrant pain and fever. Cholestatic jaundice is characterised by a relatively greater elevation of ALP and GGT than the aminotransferases. Ultrasound is indicated to determine whether there is evidence of mechanical obstruction and dilatation of the biliary tree.

Hepatomegaly

• Cirrhosis can be associated with either hepatomegaly or reduced liver size in advanced disease.
• Although all causes of cirrhosis can involve hepatomegaly, it is much more common in alcoholic liver disease and haemochromatosis.

Ascites

accumulation of free fluid in the peritoneal cavity
C/F:
• Asymptomatic
• distension, fullness in the flanks, shifting dullness on percussion and, when the ascites is marked, a fluid thrill
• eversion of the umbilicus, herniae, abdominal striae, divarication of the recti and scrotal oedema. Dilated superficial abdominal veins may be seen if the ascites is due to portal hypertension

Pathophysiology

Investigations

• Ultrasonography
• Paracentesis
• amylase
• Cytological examination
• leucocyte counts
• Laparoscopy

Measurement of the protein concentration and the serum–ascites albumin gradient (SAAG) are used to distinguish a transudate from an exudate. Cirrhotic patients typically develop a transudate with a total protein concentration below 25 g/L and relatively few cells. However, in up to 30% of patients, the total protein concentration is more than 30 g/L. In these cases, it is useful to calculate the SAAG by subtracting the concentration of the ascites fluid albumin from the serum albumin. A gradient of more than 11 g/L is 96% predictive that ascites is due to portal hypertension. Venous outflow obstruction due to cardiac failure or hepatic venous outflow obstruction can also cause a transudative ascites, as indicated by an albumin gradient above 11 g/L but, unlike in cirrhosis, the total protein content is usually above 25 g/L.
SAAG

Management
• Sodium and water restriction
• Diuretics
• Paracentesis
• Transjugular intrahepatic portosystemic stent shunt
• Peritoneo-venous shunt

Sodium and water restriction

• Restriction of sodium intake to 100 mmol/day (‘no added salt diet’) is usually adequate.
• Drugs containing relatively large amounts of sodium, and those promoting sodium retention such as non-steroidal anti-inflammatory drugs (NSAIDs), must be avoided.
• Restriction of water intake to 1.0–1.5 L/day is necessary only if the plasma sodium falls below 125 mmol/L.

Paracentesis

• First-line treatment of refractory ascites is large-volume paracentesis.
• Paracentesis to dryness is safe, provided the circulation is supported with an intravenous colloid such as human albumin (6–8 g per litre of ascites removed, usually as 100 mL of 20% human albumin solution (HAS) for every 1.5–2 L of ascites drained) or another plasma expander.

Transjugular intrahepatic portosystemic stent shunt

A transjugular intrahepatic portosystemic stent shunt (TIPSS) can relieve resistant ascites but does not prolong life; it may be an option where the only alternative is frequent, large-volume paracentesis. It can be used in patients awaiting liver transplantation or in those with reasonable liver function, but can aggravate encephalopathy in those with poor function.
Transjugular intrahepatic portosystemic stent shunt

Peritoneo-venous shunt

The peritoneo-venous shunt is a long tube with a non-return valve running subcutaneously from the peritoneum to the internal jugular vein in the neck; it allows ascitic fluid to pass directly into the systemic circulation.

Complications, including infection, superior vena caval thrombosis, pulmonary oedema, bleeding from oesophageal varices and disseminated intravascular coagulopathy, limit its use and insertion of these shunts is now rare.

Complications

• Renal failure
• Hepatorenal syndrome
• Spontaneous bacterial peritonitis

Renal failure
Renal failure can occur in patients with ascites. It can be pre-renal due to vasodilatation from sepsis and/or diuretic therapy, or due to hepatorenal syndrome.

Hepatorenal syndrome

This occurs in 10% of patients with advanced cirrhosis complicated by ascites. There are two clinical types; both are mediated by renal vasoconstriction due to underfilling of the arterial circulation.

• Type 1 hepatorenal syndrome is characterised by progressive oliguria, a rapid rise of the serum creatinine and a very poor prognosis (without treatment, median survival is less than 1 month). There is usually no proteinuria, a urine sodium excretion of less than 10 mmol/day and a urine/ plasma osmolarity ratio of more than 1.5. Other non-functional causes of renal failure must be excluded before the diagnosis is made. Treatment consists of albumin infusions in combination with terlipressin and is effective in about two-thirds of patients. Haemodialysis should not be used routinely because it does not improve the outcome.
Patients who survive should be considered for liver transplantation.
• Type 2 hepatorenal syndrome usually occurs in patients with refractory ascites, is characterised by a moderate and stable increase in serum creatinine, and has a better prognosis.
Types:

Spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) may present with abdominal pain, rebound tenderness, absent bowel sounds and fever in a patient with obvious features of cirrhosis and ascites. Abdominal signs are mild or absent in about one-third of patients, and in these patients hepatic encephalopathy and fever are the main features. Diagnostic paracentesis may show cloudy fluid, and an ascites neutrophil count above 250 × 106/L almost invariably indicates infection. The source of infection cannot usually be determined, but most organisms isolated are of enteric origin and Escherichia coli is most frequently found. Ascitic culture in blood culture bottles gives the highest yield of organisms. SBP needs to be differentiated from other intra-abdominal emergencies, and the finding of multiple organisms on culture should arouse suspicion of a perforated viscus. Treatment should be started immediately with broadspectrum antibiotics, such as cefotaxime or piperacillin/ tazobactam). Recurrence of SBP is common but may be reduced with prophylactic quinolones such as norfloxacin or ciprofloxacin.

Only 10–20% of patients survive 5 years from the first appearance of ascites due to cirrhosis. The outlook is not universally poor, however, and is best in those with well-maintained liver function and a good response to therapy. The prognosis is also better when a treatable cause for the underlying cirrhosis is present or when a precipitating cause for ascites, such as excess salt intake, is found. The mortality at 1 year is 50% following the first episode of bacterial peritonitis.
Prognosis (of ascites)

Hepatic encephalopathy

Hepatic encephalopathy is a neuropsychiatric syndrome caused by liver disease.
As it progresses, confusion is followed by coma. Confusion needs to be differentiated from delirium tremens and Wernicke’s encephalopathy, and coma from subdural haematoma, which can occur in alcoholics after a fall. Features include changes of intellect, personality, emotions and consciousness, with or without neurological signs. The degree of encephalopathy can be graded from 1 to 4, depending on these features, and this is useful in assessing response to therapy. When an episode develops acutely, a precipitating factor may be found.

The earliest features are very mild and easily overlooked but, as the condition becomes more severe, apathy, inability to concentrate, confusion, disorientation, drowsiness, slurring of speech and eventually coma develop. Convulsions sometimes occur. Examination usually shows a flapping tremor (asterixis), inability to perform simple mental arithmetic tasks or to draw objects such as a star, and, as the condition progresses, hyper-reflexia and bilateral extensor plantar responses. Hepatic encephalopathy rarely causes focal neurological signs; if these are present, other causes must be sought. Fetor hepaticus, a sweet musty odour to the breath, is usually present but is more a sign of liver failure and portosystemic shunting than of hepatic encephalopathy. Rarely, chronic hepatic encephalopathy (hepatocerebral degeneration) gives rise to variable combinations of cerebellar dysfunction, Parkinsonian syndromes, spastic paraplegia and dementia.
Clinical features:

Hepatic encephalopathy is thought to be due to a disturbance of brain function provoked by circulating neurotoxins that are normally metabolised by the liver. Accordingly, most affected patients have evidence of liver failure and portosystemic shunting of blood, but the balance between these varies from individual to individual. Some degree of liver failure is a key factor, as portosystemic shunting of blood alone hardly ever causes encephalopathy. The ‘neurotoxins’ causing encephalopathy are unknown, but they are thought to be mainly nitrogenous substances produced in the gut, at least in part by bacterial action. These substances are normally metabolised by the healthy liver and excluded from the systemic circulation.
Pathophysiology

Ammonia has traditionally been considered an important factor. Recent interest has focused on γ-aminobutyric acid (GABA) as a mediator, along with octopamine, amino acids, mercaptans and fatty acids that can act as neurotransmitters.
The brain in cirrhosis may also be sensitised to other factors such as drugs that can precipitate hepatic encephalopathy.
Disruption of the function of the blood–brain barrier is a feature of acute hepatic failure and may lead to cerebral oedema.
Pathophysiology

The diagnosis can usually be made clinically, but when doubt exists, an electroencephalogram (EEG) shows diffuse slowing of the normal alpha waves with eventual development of delta waves. The arterial ammonia is usually increased in patients with hepatic encephalopathy. However, increased concentrations can occur in the absence of clinical encephalopathy, rendering this investigation of little diagnostic value.
Investigations

The principles are to treat or remove precipitating causes and to suppress the production of neurotoxins by bacteria in the bowel. Dietary protein restriction is rarely needed and is no longer recommended as first-line treatment because it is unpalatable and can lead to a worsening nutritional state in already malnourished patients. Lactulose (15–30 mL 3 times daily) is increased gradually until the bowels are moving twice daily. It produces an osmotic laxative effect, reduces the pH of the colonic content, thereby limiting colonic ammonia absorption, and promotes the incorporation of nitrogen into bacteria. Rifaximin (400 mg 3 times daily) is a well tolerated, non-absorbed antibiotic that acts by reducing the bacterial content of the bowel and has been shown to be effective. It can be used in addition, or as an alternative, to lactulose if diarrhoea becomes troublesome. Chronic or refractory encephalopathy is one of the main indications for liver transplantation .

Management

CIRRHOSIS
Cirrhosis is characterised by diffuse hepatic fibrosis and nodule formation. It can occur at any age, has significant morbidity and is an important cause of premature death. Worldwide, the most common causes are chronic viral hepatitis, prolonged excessive alcohol consumption and NAFLD.
Cirrhosis is the most common cause of portal hypertension and its complications. Any condition leading to persistent or recurrent hepatocyte death, such as chronic hepatitis C infection, alcoholic liver disease (ALD) or NAFLD may lead to cirrhosis. It may also occur in prolonged biliary damage or obstruction, as is found in primary biliary cirrhosis (PBC), primary sclerosing cholangitis and post-surgical biliary strictures.
Persistent blockage of venous return from the liver, such as occurs in venoocclusive disease and Budd–Chiari syndrome, can also result in cirrhosis.

Following liver injury, stellate cells in the space of Disse are activated by cytokines produced by Kupffer cells and hepatocytes. This transforms the stellate cell into a myofibroblast-like cell, capable of producing collagen, pro-inflammatory cytokines and other mediators that promote hepatocyte damage and tissue fibrosis.
Cirrhosis is a histological diagnosis. It evolves over years as progressive fibrosis and widespread hepatocyte loss lead to distortion of the normal liver architecture that disrupts the hepatic vasculature, causing portosystemic shunts.
These changes usually affect the whole liver, but in biliary cirrhosis (e.g. PBC) they can be patchy.
Pathophysiology

Cirrhosis can be classified histologically into:

• Micronodular cirrhosis, characterised by small nodules about 1 mm in diameter and typically seen in alcoholic cirrhosis.
• Macronodular cirrhosis, characterised by larger nodules of various sizes. Areas of previous collapse of the liver architecture are evidenced by large fibrous scars

The clinical presentation is highly variable. Some patients are asymptomatic and the diagnosis is made incidentally at ultrasound or at surgery. Others present with isolated hepatomegaly, splenomegaly, signs of portal hypertension or hepatic insufficiency. When symptoms are present, they are often non-specific and include weakness, fatigue, muscle cramps, weight loss, anorexia, nausea, vomiting and upper abdominal discomfort. Cirrhosis will occasionally present because of shortness of breath due to a large right pleural effusion, or with hepatopulmonary syndrome. Hepatomegaly is common when the cirrhosis is due to ALD or haemochromatosis. Progressive hepatocyte destruction and fibrosis gradually reduce liver size as the disease progresses in other causes of cirrhosis. A reduction in liver size is especially common if the cause is viral hepatitis or autoimmune liver disease. The liver is often hard, irregular and non-tender. Jaundice is mild when it first appears and is due primarily to a failure to excrete bilirubin.
Clinical features

Palmar erythema can be seen early in the disease, but is of limited diagnostic value, as it occurs in many other conditions associated with a hyperdynamic circulation, including normal pregnancy, as well as being found in some healthy people.
Spider telangiectasias occur and comprise a central arteriole (which occasionally raises the skin surface), from which small vessels radiate. They vary in size from 1 to 2 mm in diameter, and are usually found only above the nipples. One or two small spider telangiectasias may be present in about 2% of healthy people and may occur transiently in greater numbers in the third trimester of pregnancy, but otherwise they are a strong indicator of liver disease. Florid spider telangiectasia, gynaecomastia and parotid enlargement are most common in alcoholic cirrhosis.

Clinical features

Pigmentation is most striking in haemochromatosis and in any cirrhosis associated with prolonged cholestasis. Pulmonary arteriovenous shunts also develop, leading to hypoxaemia and eventually to central cyanosis, but this is a late feature. Endocrine changes are noticed more readily in men, who show loss of male hair distribution and testicular atrophy.
Gynaecomastia is common and can be due to drugs such as spironolactone. Easy bruising becomes more frequent as cirrhosis advances.
Splenomegaly and collateral vessel formation are features of portal hypertension, which occurs in more advanced disease.
Ascites also signifies advanced disease.
Evidence of hepatic encephalopathy also becomes common with disease progression.

Nonspecific features of chronic liver disease include clubbing of the fingers and toes. Dupuytren’s contracture is traditionally regarded as a complication of cirrhosis, but the evidence for this is weak. Chronic liver failure develops when the metabolic capacity of the liver is exceeded. It is characterised by the presence of encephalopathy and/or ascites. The term ‘hepatic decompensation’ or ‘decompensated liver disease’ is often used when chronic liver failure occurs. Other clinical and laboratory features may be present; these include peripheral oedema, renal failure, jaundice, and hypoalbuminaemia and coagulation abnormalities due to defective protein synthesis.

This includes treatment of the underlying cause, maintenance of nutrition and treatment of complications, including ascites, hepatic encephalopathy, portal hypertension and varices.
Once the diagnosis of cirrhosis is made, endoscopy should be performed to screen for oesophageal varices and repeated every 2 years. As cirrhosis is associated with an increased risk of hepatocellular carcinoma (HCC), patients should be placed under regular surveillance for it.
Chronic liver failure due to cirrhosis can also be treated by liver transplantation. This currently accounts for about three-quarters of all liver transplants.

Management

• The overall prognosis in cirrhosis is poor. Many patients present with advanced disease and/or serious complications that carry a high mortality. Overall, only 25% of patients survive 5 years from diagnosis but, where liver function is good, 50% survive for 5 years and 25% for up to 10 years. The prognosis is more favourable when the underlying cause of the cirrhosis can be corrected, as in alcohol misuse, haemochromatosis or Wilson’s disease. Laboratory tests give only a rough guide to prognosis in individual patients. Deteriorating liver function, as evidenced by jaundice, ascites or encephalopathy, indicates a poor prognosis unless a treatable cause such as infection is found. Increasing bilirubin, falling albumin (or an albumin concentration < 30 g/L), marked hyponatraemia (< 120 mmol/L) not due to diuretic therapy, and a prolonged PT are all bad prognostic features.
Prognosis

The Child–Pugh score and, more recently, the MELD (Model for End-stage Liver Disease) score can be used to assess prognosis.
The MELD is more difficult to calculate at the bedside but, unlike the Child–Pugh score, includes renal function; if this is impaired, it is known to be a poor prognostic feature in end-stage disease.

Although these scores give a guide to prognosis, the course of cirrhosis can be unpredictable, as complications such as variceal bleeding may occur.