Asites Flashcards
(44 cards)
What does ascites refer to?
Detectable collection of fluid in the peritoneal cavity
Broadly, how do ascites form?
Increased pressure in the portal system means fluid leaks out of liver capillaries and other organs into the peritoneal cavity
What are symptoms of portal hypertension?
GI bleeding (if vessels rupture) + Blood in stool
Varices + Vomit blood
Ascites
Oedema
Encephalopathy
Jaundice
Caput medusa
What are symptoms of ascites?
Increased size of abdomen
Shifting dullness
Fluid thrill
Early satiety
Feeling out of breath
Jaundice
Pruritis
Severe painful distension (may be SBP)
What does “shifting dullness” refer to?
In ascites the fullness in flanks causes resonant and then dull sound when turned as fluid shifts
What is fluid thrill?
Test where patient pushes down on midline of abdomen
Examiner taps one flank and feels for the tap on the other flank.
Pressure normally should stop vibration of tap across but doesn’t if fluid is present.
What are broad concepts for ascites developing?
Low protein (decreased oncotic pressure)
Local inflammation
Flow stasis
What are reasons for inflammation which causes ascites?
Malignancy (eg ovarian)
Peritonitis (bacterial infection)
TB
What conditions cause there to be low levels of protein in the blood which can cause ascites?
Nephrotic syndrome
Hypoalbuminaemia (liver failure)
What are some conditions causing flow stasis leading to ascites?
Cirrhosis
Budd Chiari
Congestive heart failure
Constrictive pericarditis
Name some major causes of ascites?
Cirrhosis
Malignancy
Heart failure
TB
Pancreatitis
How does fibrosis lead to portal hypertension?
Fibrotic tissue replaces healthy liver tissue, disrupting the liver architecture.
Results in increased resistance to blood flow = portal hypertension
How does portal hypertension lead to ascites?
Increased pressure forces blood out of the vessels into the peritoneal cavity
Who are the kidneys involved in fibrosis and ascites?
Fibrosis causes portal hypertension which triggers splanchnic vasodilation to redistribute blood.
Causes lower blood pressure at kidneys so RAAS activated.
leads to increased water and sodium retention which contributes to fluid accumulation in peritoneal cavity.
How do albumin levels in cirrhosis contribute to ascites?
Cirrhosis leads to hypoalbuminemia resulting in lower oncotic pressure so more fluid moves out of vessels into cavity compared to in.
Also inflammation of liver and peritoneum increases the permeability of vessels so more proteins like albumin can leak out.
What system is unable to keep up with the accumulation of fluid in the peritoneum causing ascites to develop?
Lymphatic system
At what volume does ascites typically become clinically detectable?
500ml
What classifies as stage 1 ascites?
Detectable only after careful examination or ultrasound
What classifies as stage 2 ascites?
Easily detectable but of relatively small volume
What classifies as stage 3 ascites?
Obvious, not tense ascites
What classifies as stage 4 ascites?
Tense ascites (large)
How is ascites diagnosed?
Shifting dullness
Ascitic tap:
Neutrophilia
Raised ESR and CRP
Measure protein
MC&S (identify causative organism)
What should be excluded in suspected ascites?
Pregnancy: take B-hCG test
Bowel obstruction: abdominal XR
Perforated colon: Erect CXR showing air under diaphragm
How is ascites managed?
Low sodium diet
Aldosterone agonists eg spironolactone (increases natriuresis so more fluid flushed out whilst conserving potassium)
Fluid restriction
Paracentesis (ascitic tap)
Prophylactic Abx
TIPS (transjugular intrahepatic portosystemic shunt)
Liver transplant
