APPROACH TO A
PATIENT WITH ASCITES
A MINI LECTURE 4/23/15
OBJECTIVES
• Be able to define ascites
• Understand the general causes of ascites
• Know the indications for giving albumin after a
paracentesis
• Be able to calculate a SAAG score and know its
relevance in diagnosing the cause of ascites
• Be able to understand the etiology of ascites based
on the fluid analysis
DEFINING ASCITES
An abnormal collection of fluid (>25 ml) within the
abdominal cavity
CAUSES OF ASCITES
• More than 80% of cases of ascites are the result of
cirrhosis.
• Cardiac ascites, peritoneal carcinomatosis, and
mixed ascites account for 10-15% of cases
• Less common causes include: massive hepatic
metastasis, infections (TB and chlamydia),
pancreatitis, and renal disease (nephrotic
syndrome)
PATHOPHYSIOLOGY OF ASCITES
• In patients with cirrhosis ascites is the result of portal
hypertension.
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•
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Increased hepatic resistance from fibrosis causes a disruption of
normal architecture and impedes blood flow
Activation of hepatic stellate cells lead to smooth muscles
contracting
There is a decrease in production of endothelial nictric oxide
synthetase which causes further vasoconstriction
• With infections and cancer the ascites is due to leaking of
protein rich fluid from cells
• Nephrotic syndromes cause loss of protein in the urine which
leads to decreased extracellular oncotic pressure
• Pancreatitis can lead to enzyme leaking into the abdominal
cavity and then cause ascites
LABS TO ORDER ON A PATIENT WITH
ASCITES
• Check your liver function panel and basic
metabolic panel
• Check CBC and Coags
• Blood cultures if clinical suspicion for infection is high
DIAGNOSTIC VS THERAPEUTIC TAP
• Diagnostic:
- Evaluate the etiology of the ascites
- Can be done with as little as 60cc of fluid
• Therapeutic:
- Used to relieve intra-abdominal pressure
- All tests performed on a diagnostic tap can be ordered on
a therapeutic tap
- Postparacentesis albumin infusion is unnecessary for a single
paracentesis of less than 4 to 5 L, but for large-volume
paracenteses, an albumin infusion of 8 to 10 g per liter of
fluid removed can be considered
TESTS TO ORDER ON ASCITIC FLUID
• Check protein, albumin, glucose, and LDH
• Cell count
• Gram stain, and culture- in new onset ascites SBP
needs to be ruled out
• Other tests to consider- cytology, pancreatic
enzymes
THE SAAG
Serum- ascites albumin gradient = Serum albumin
minus the albumin in the ascites; this value correlates
directly with the portal pressure
If SAAG is > 1.1 g/dl then ascites is the result of portal
hypertension
If SAAG is < 1.1 g/dl then ascites is non-portal in
etiology
CASE
54 year old male being admitted to the hospital with
abdominal swelling for the past week. Has a history of
IV drug abuse and heavy alcohol use. He states that
his abdomen feels tight, but is not particularly tender.
He states that this has never happened to him before.
On exam the patient is afebrile and vitals are WNL,
eyes are icteric and the patient is grossly jaundiced.
Abdomen is grossly distended with a positive fluid
wave, and the patient has marked gynecomastia
and numerous telangiectasias on his chest and arms.
When you perform the paracentesis what do you think
the fluid will show?
SUMMARY
• Ascites is an abnormal collection of fluid within the
abdomen
• 80% of cases of ascites are due to cirrhosis, but can
also be due to heart failure, pancreatitis, infections,
cancer, and kidney disease
• If more than 5L of fluid is removed from a tap, you
can give 8-10 g/l of albumin after the paracentesis
• The SAAG score is a direct correlation to the portal
pressure
• On the ascitic fluid look at the albumin, total
protein, and cell counts