Serum-to-Ascites Albumin Gradient
- Infection (Peritoneal TB)
- Peritoneal Cancer
- Pancreatic Ascites
- Biliary Ascites
- Nephrotic Syndrome
- Lupus Serositis
- Bowel Infarction or Obstruction
- Post-Op Lymphatic leak
||Propanolol 40 mg PO bid
or Nadolol 20-40 mg PO qd.
Octreotide 50 mcg x 1, then 50 mcg/hr IV drip x 3-5 d after endoscopic
variceal band ligation.
(WBC > 500,
Neutrophils > 250)
IV Q8H x 5-7d
Multi. Liver Mets.
Fatty liver of pregnancy
Cell Count & differential
- The cell count with differential is the single most useful test
performed on ascitic fluid to evaluate for infection and should be ordered on
every specimen, including therapeutic paracentesis specimens (ie, a paracentesis
being performed as part of the treatment of ascites).
- Ascitic fluid infection is a reversible cause of deterioration and a preventable
cause of death in patients with cirrhosis and ascites.
- The key to survival is early detection and treatment.
- The cell count should be available within one hour, while the
culture takes several hours to days.
- Antibiotic treatment should be considered in any patient with a
corrected neutrophil count ≥250/mm3.
- WBC Correction:
- The white blood cell and neutrophil counts need to be corrected in
patients with bloody samples.
- One white blood cell should be subtracted from the white blood
cell count for every 750 red blood cells to yield the "corrected white blood
cell count", and
- One neutrophil should be subtracted from the absolute neutrophil
count for every 250 red blood cells to yield the "corrected neutrophil count".
- In bloody ascites, the corrected neutrophil count is frequently <0
due to remote hemorrhage with lysis of neutrophils.
- Ascitic fluid can be classified as an exudate if the total protein
concentration is ≥2.5 or 3 g/dL and a
transudate if it is below this cut-off. However, the
exudate/transudate system of ascitic fluid
classification has been replaced by the SAAG.
- Despite its problems, the ascitic fluid total protein concentration
remains of some value. This parameter does not change with development
of spontaneous bacterial peritonitis (SBP), and patients with a value
< 1 g/dL have a high risk of SBP.
- Patients with ascitic fluid that has a corrected neutrophil count ≥250
cells/mm3 and meets two out of the following
three criteria are unlikely to have SBP and warrant immediate evaluation to
determine if bowel perforation into ascites has occurred:
- Total protein >1
- Glucose <50
mg/dL (2.8 mmol/L)
- LDH greater than the
upper limit of normal for serum
- The total protein concentration may also help differentiate
uncomplicated ascites from cirrhosis from cardiac ascites, both of which
have a SAAG ≥1.1 g/dL (≥11
g/L). In the case of ascites from cirrhosis,
the total protein is <2.5 g/dL (<25
g/L), whereas in cardiac ascites it is ≥2.5
g/dL (≥25 g/L).
- In patients with nephrotic ascites, the SAAG is <1.1
g/dL (<11 g/L),
and the total protein in the ascites of <2.5 g/dL
- Cultures of ascitic fluid should be obtained on specimens from
patients who are being admitted to the hospital with ascites and those
who deteriorate with fever, abdominal pain, azotemia, acidosis, or
- By comparison, therapeutic paracentesis samples in patients without
symptoms of infection do not need to be cultured.
- An adequate volume of ascitic fluid (generally 10 mL per bottle, but
the amount varies according to the manufacturer of the bottle) should be
inoculated into aerobic and anaerobic blood culture bottles at the
bedside; this method is more sensitive for detecting bacterial growth in
ascitic fluid than conventional culture methods.
- Bedside inoculation of the blood culture bottles is preferable to
delayed inoculation of the bottles in the microbiology laboratory
- The ascitic fluid glucose concentration is similar to that in serum
unless glucose is being consumed in the peritoneal cavity by white blood
cells or bacteria.
- Malignant cells also consume glucose; thus, the concentration of
glucose may be low in peritoneal carcinomatosis.
- In the setting of bowel perforation (eg, perforated ulcer or
diverticulum) into ascitic fluid, glucose may be undetectable.
- Because lactate dehydrogenase (LDH) is a much larger molecule than
glucose, it enters ascitic fluid less readily.
- The ascitic fluid/serum
(AF/S) ratio of LDH is approximately 0.4 in
uncomplicated ascites due to cirrhosis.
- In SBP, the ascitic fluid LDH level rises such that the mean ratio
- If the LDH ratio is > 1.0, LDH is being produced in or
released into the peritoneal cavity, usually because of infection,
bowel perforation, or tumor.
- Approximately 10,000 bacteria/mL are
required for detection by Gram stain, while the median concentration of
bacteria in SBP is only one organism/mL.
Thus, a Gram stain of ascitic fluid is analogous to a Gram stain of
blood in bacteremia; it is only positive when there is an enormous
- The Gram stain is most helpful in ruling in free perforation of the
bowel into ascites, in which case sheets of multiple bacterial forms can
- A syringe or tube of fluid must be submitted to the laboratory in
addition to the culture bottles when requesting a Gram stain.
- The mean ascitic fluid amylase concentration is about 40 int.
unit/L in uncomplicated ascites due to
cirrhosis, and the AF/S ratio of amylase is
- The ascitic fluid amylase concentration rises above this level in
the setting of pancreatitis or bowel perforation into ascites.
- In pancreatic ascites, the ascitic fluid amylase
concentration is approximately 2000 int.
unit/L, and the AF/S ratio is approximately 6.0
Tuberculosis Smear & Culture
- Direct smear – The direct smear of ascitic fluid has only 0 to 2 percent
sensitivity for detecting Mycobacteria.
Studies have not encountered a single true positive ascitic fluid Mycobacterial
- Culture –
When 1 liter of fluid is cultured, sensitivity for Mycobacteria reportedly
reaches 62 to 83%.
However, most laboratories can only process 50 mL of ascitic fluid for
- Peritoneoscopy –
Peritoneoscopy with culture of a biopsy specimen has a sensitivity for detecting
tuberculous peritonitis that approaches 100%.
Fluid and tissue can be sent for PCR for tuberculosis.
- Cell count – Tuberculous
peritonitis can mimic the culture-negative variant of SBP, but mononuclear cells
usually predominate in tuberculosis.
deaminase – Adenosine deaminase is a purine-degrading enzyme that is necessary
for the maturation and differentiation of lymphoid cells. Adenosine deaminase
activity of ascitic fluid has been proposed as a useful non-culture method of
detecting tuberculous peritonitis; however, patients with tuberculous
peritonitis who also have cirrhosis usually have falsely low values.
This test is useful in countries such as India, but it is of very limited
utility in the United States because most patients in the United States with tuberculous peritonitis also have cirrhosis.
- Almost 100% of patients with peritoneal carcinomatosis will have
positive ascitic fluid cytology due to the presence of viable malignant
cells exfoliating into the ascitic fluid. However, only about 2/3 of
patients with malignancy-related ascites have peritoneal carcinomatosis.
The remaining patients have massive liver metastases, chylous ascites
due to lymphoma, or hepatocellular carcinoma; these patients usually
have negative cytology. As a result, the overall sensitivity of
cytology smears for the detection of malignant ascites is 58-75 %.
- Hepatomas rarely metastasize to the peritoneum.
- Measurement of carcinoembryonic antigen (CEA) in ascitic fluid has
been proposed as a helpful test in detecting malignancy-related ascites.
However, the study that validated CEA was small and did not subgroup
patients based on the type of cancer.
- CEA may be of some utility in ascitic fluid analysis, but its
precise value remains unclear
- A triglyceride concentration should be obtained on ascitic fluid
that is milky.
- Chylous ascites has a triglyceride content > 200
mg/dL (2.26 mmol/L)
and usually > 1000 mg/dL (11.3
is the extravasation of milky chyle into the peritoneal
cavity. This can occur de novo as a result of trauma or obstruction of the
lymphatic system. Moreover, an existing clear ascitic fluid can turn chylous as
a secondary event.
True chylous ascites is defined as the presence of ascitic fluid with high fat
(triglyceride) content, usually higher than 110 mg/dL
Source: Medscape, Uptodate.
- The bilirubin concentration should be measured in patients with
- As mentioned above, an Ascitic fluid bilirubin value > Serum
suggests bowel or biliary perforation into ascites
- Measurement of pro-brain natriuretic peptide in serum can help
distinguish ascitic fluid due to cirrhosis from ascitic fluid due to
- Some tests of ascitic fluid appear to be useless.
- These include pH, lactate, and "humoral tests of malignancy" such as
fibronectin, cholesterol, and many others