Synopsis
Distinguish fluid, liver and spleen enlargement at the bedside, identify decompensated cirrhosis, spontaneous bacterial peritonitis, malignancy and vascular disease promptly, and use ultrasound plus diagnostic paracentesis to establish mechanism.
- New ascites is a diagnosis to explain, not merely a sign to diurese: confirm it with ultrasound and sample it unless a clear contraindication or specialist reason exists.
- Any patient with cirrhosis and ascites admitted acutely should have prompt diagnostic paracentesis, including when abdominal pain or fever is absent.
- Ascitic neutrophils at or above 250 cells/mm³ support spontaneous bacterial peritonitis and should trigger immediate treatment under the local pathway.
- Calculate the serum-ascites albumin gradient from paired samples: 11 g/L or greater supports portal-hypertensive mechanisms, while a lower gradient redirects the differential.
- Massive paracentesis treats tense or refractory ascites; give albumin according to current guidance and the volume removed, and monitor renal function and circulation.
- A pulsatile tender liver suggests congestion, a hard irregular liver suggests malignancy or cirrhosis, and a smooth massive liver has a different differential; examination alone cannot settle cause.
- Splenomegaly may reflect portal hypertension, haematological malignancy, infection, haemolysis or storage disease; cytopenias are not automatically hypersplenism.
- Tense ascites with respiratory compromise, shock, peritonism, acute kidney injury or encephalopathy needs same-day senior and hepatology review.
Key red flags
Fever, abdominal pain, encephalopathy, hypotension, ileus, acute kidney injury or otherwise unexplained decompensation can be the presentation. A painless abdomen is common enough that routine admission taps matter.
Painful hepatomegaly, rapid ascites, raised JVP, oedema or a pulsatile liver suggests cardiac congestion or hepatic venous outflow obstruction; Doppler and cardiac assessment are important.
Sudden left upper-quadrant pain, shoulder-tip pain, shock or falling haemoglobin in a person with splenomegaly raises rupture or infarction and requires immediate resuscitation and imaging.
Investigation priorities
Confirm ascites, measure liver and spleen, assess contour and focal lesions, and evaluate portal and hepatic venous flow while identifying a safe paracentesis window.
Management branches
New ascites, or cirrhosis with ascites during an acute hospital admission.
- Assess ABCDE, renal function, encephalopathy, bleeding and sepsis; use ultrasound to confirm fluid and select a safe site.
- Perform prompt diagnostic paracentesis and send cell count, bedside cultures, albumin and protein, adding cytology or other tests only where indicated.
- Calculate SAAG and combine it with protein, imaging and clinical context to separate portal-hypertensive, malignant, cardiac, pancreatic and infectious mechanisms.
- Assign ownership for cultures and cytology that will mature after the initial decision.