PE - Approach to Ascites

Question 1

List important negatives to mention in a patient w/ascites

Answer 1

1) Stigmata of chronic liver disease
- cirrhosis is most common cause of ascites

2) Signs of hepatic encephalopathy
- always present if reversible acute on chronic liver failure
- may be present if irreversible chronic liver disease

3) Jugular venous pressure for volume status
- low/normal JVP –> cirrhosis (systemic vasodilation)
- elevated –> CKD, heart failure, constrictive pericarditis, atrial myxoma

4) Generalized lymphadenopathy
1. infection (EBV, CMV, HHV-6, HIV, toxoplasmosis, Bartonella)
2. malignancy
3. hematological malignancy
4. SLE
5. sarcoidosis

5) Caput medusae
- occlude vessels below umbilicus
- blood flow away from umbilicus = portal HT
- blood flow towards umbilicus = IVC obstruction

Question 2

Explain the mechanism of ascites in generalized lymphadenopathy

Answer 2

1) Involvement of retroperitoneal lymph nodes

2) Lymphatic drainage of abdomen impaired causing ascites

Question 3

List the 6Fs of abdominal masses

Answer 3

1) Fat
2) Fluid
3) Flatulence
4) Feces
5) Flaming tumour
6) Fetus

Question 4

Explain the mechanism of ascites in nephrotic syndrome

List some causes of nephrotic syndrome

Answer 4

1) Hypoalbuminemia in nephrotic syndrome causes loss of water into the extravascular space causing ascites
2) Causes of nephrotic syndrome include
1. Idiopathic
2. Rheumatoid arthritis
3. SLE

Question 5

List some causes of hypoalbuminemia

Answer 5

1) Malnutrition
2) Nephrotic syndrome
3) Liver disease

Question 6

List the common causes of ascites

Answer 6

1) Cirrhosis (75%)
2) Malignancy (10%)
3) Heart failure (3%)
4) Tuberculosis (2%)
5) Pancreatitis (1%)

Question 7

Outline initial investigations to make the etiological diagnosis of ascites

Answer 7

Blood tests

1) LFT –> check for impaired liver function in cirrhosis
2) CBC –> PLT (thrombocytopenia suggest hypersplenism secondary to portal HT) PLT less than 50 may also be contraindication for further invasive procedures
3) INR –> ?less than 1.7-1.5
4) Prothrombin time –> assess liver function + coagulopathy

Abdominal USG

1) R/o hepatic or other intra-abdominal masses suggestive of malignancy
2) Splenomegaly suggests portal HT
3) Hepatic vein + portal vein Doppler to r/o thrombosis

Diagnostic paracentesis

1) Ascitic fluid albumin + total protein
2) Ascitic fluid differential WCC
3) Ascitic fluid gram stain + culture
4) Ascitic fluid cytology

Question 8

Outline the method of classifying ascites

Answer 8

Serum ascites-albumin gradient (SA-AG)
SA-AG= serum albumin - ascific fluid albumin
- less than 11 = exudative
- more than 11 = transudative

Question 9

Explain the pathophysiology of ascites and edema in cirrhosis

Answer 9

1) In cirrhosis, ascites only occurs after development of portal HT
2) Disturbed portal blood flow in cirrhotic liver causes fluid accumulation in peritoneum
3) Cirrhosis is a state of systemic vasodilation which also dilates splanchnic circulation –> increased blood flow through portal vein increases portal vein pressure –> further reduces effective circulating volume and blood pressure –> RAAS + sympathetic activation –> salt + water retention –> edema + ascites

Question 10

Outline the initial management for ascites in cirrhosis

Answer 10

1) Dietary Na restriction –> reduce edema + ascites
2) Fluid restriction –> reduce edema + ascites
3) Diuretics –> w/aldosterone antagonists first then loop diuretics AFTER achieving appropriate Na levels

Question 11

Explain the pathophysiology of hepatorenal syndrome

Answer 11

1) Hepatorenal syndrome can be considered the endstage of the spectrum of portal HT and ascites
2) Systemic vasodilation continually reduces effective circulating volume
3) This induces a vasoconstrictor response in which renal blood flow is reduced thus reducing GFR
4) Results in progressive renal impairment in end stage liver disease despite structurally normal kidneys