Advanced Physical Diagnosis
  • Techniques
  • Demonstrations
Associated Evaluations
  • Patient HX
  • Physical Exam
  • Laboratory & Imaging
Differential Dx
Evidence Base
• History
• Physical Exam
• Laboratory Tests
Teaching Tips
[Skill Modules >> Liver & Ascites >> Laboratory & Imaging ]

Laboratory & Imaging: Liver & Ascites

Laboratory: Examination of Peritoneal fluid

Analysis of ascitic fluid, unlike pleural fluid, generally requires few laboratory tests. Tests on ascitic fluid that are useful in the initial work-up of ascites of unknown etiology include:

Gross Appearance  
Cell Counts WBC with differential and PMN count RBCs
Albumin with calculation of the serum - ascites albumin gradient (see Differential Diagnosis for discussion of the albumin gradient utility in etiology)
Gram's stain and culture(bedside culture required) if tuberculosis is suspected, peritoneal biopsy of higher yield than tuberculosis smear and culture
Note: For the patient with serial paracentesis procedures due to reaccumulation of fluid or for therapeutic indications, it may be necessary only to perform WBC, PMN, RBC counts and gram's stain and culture. SBP should always be suspected.

back to top

Tests that rarely help to clarify etiology of ascites:

  • LDH
  • Total protein
  • Glucose
  • Bilirubin
  • Ascitic fluid pH
  • CEA


back to top