Ascitic Fluid


  • classified according to serum-ascites albumin gradient (SAAG)


High SAAG (“transudate”)

  • cirrhosis, hepatic failure, hepatic venous occlusion, constrictive pericarditis, kwashiorkor, cardiac failure, alcoholic hepatitis, liver metastasis

Low SSAG (“exudate”)

  • malignancy, infection (bacterial, fungal, Tb), pancreatitis, nephrotic syndrome, bowel obstruction or infarction, bile leak


  • vasculitis, hypothyroidism


  • ICU (to rule out infection)
  • PUO
  • suspected malignancy

-> if sudden onset: order U/S to check patency of hepatic veins and portal system


Things to put on the Lab Form:

  • albumin
  • LDH
  • glucose
  • amylase
  • pH
  • triglycerides
  • WCC
  • gram stain and culture (put some fluid into blood culture bottles)
  • cell count and differential
  • cytology

Serum:Ascitic Albumin Gradient (SAAG) = serum albumin – ascitic fluid albumin

  • > 11g/L = high SAAG = transudate
  • < 11g/L = low SAAG = exudate

Cell count and differential

  • > 250 neutrophils/mm3 = spontaneous bacterial peritonitis
  • > 250 WCC = spontaneous bacterial peritonitis
  • polymorphonuclear cells – bacterial
  • mononuclear cells – Tb or fungal

Gram stain and culture

  • monomicrobial = SBP
  • polymicrobial = secondary bacterial peritonitis -> search for perforated viscus


  • < 225U/L = transudate
  • > 225U/L = exudate


  • normal in SBP
  • low in secondary bacterial peritonitis


  • increased in pancreatic ascites


  • < 7.0 suggests bacterial infection


  • increased in chylous ascites


  • malignant cells


  • treat cause
  • drain for symptomatic relief
  • if draining > 5L -> give infusion of albumin (prevents circulatory dysfunction)
  • SBP: antibiotics + albumin infusion (1.5g/kg)
  • cirrhosis: frusemide, spironolactone, Na+ restriction, TIPS procedure
  • if no obvious cause found -> laparoscopy to find out whether malignant or infectious

References and Links

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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