1. Approach to Ascites
Updated by Daniel Kim, 06/2017

2. Objectives Become familiar with the different etiologies of ascites
Know the indications for paracentesis
Understand the diagnostic approach to evaluating ascites

3. Ascites classification
Portal Hypertension
Cirrhosis
Liver Disease (ie. Alcoholic hepatitis, acute liver failure)
Hepatic Veno-occlusive Disease (ie. Budd Chiari)
CHF
Constrictive Pericarditis
Hypoalbuminemia
Nephrotic Syndrome
Protein-Losing Enteropathy
Severe malnutrition
Peritoneal Disease
Malignant Ascites
Infectious Peritonitis (ie. TB, fungal)
Peritoneal Dialysis
There are many different etiologies of ascites, obviously the most common being related to cirrhosis
The easiest way to think about it is by classifying what the underlying pathophysiology is
Whether related to:
1) portal hypertension (increased hydrostatic pressures)
2) hypoalbuminemia (decreased oncotic pressures)
3) peritoneal disease (increased diffusing capacity)
What are the top 3 most common etiologies??

4. Ascites classification
Portal Hypertension
Cirrhosis**
Liver Disease (ie. Alcoholic hepatitis, acute liver failure)
Hepatic Veno-occlusive Disease (ie. Budd Chiari)
CHF**
Constrictive Pericarditis
Hypoalbuminemia
Nephrotic Syndrome
Protein-Losing Enteropathy
Severe malnutrition
Peritoneal Disease
Malignant Ascites**
Infectious Peritonitis (ie. TB, fungal)
Peritoneal Dialysis
Most common etiologies
1) Cirrhosis – 81%
2) Malignancy – 10%
3) CHF – 3%
All other etiologies are <=2%

5. Diagnostic evaluation
Imaging
Ultrasound CT
MRI
Serology
CBC with diff
CMP
Coags
Imaging
Helps assess for fluid collection
Can aid in evaluating the underlying etiology (ie. Liver nodules, dilated portal veins, malignancy)
Serology
Again can aid in evaluating the underlying etiology
Ie. Abnormal LFTs/coags pointing towards hepatic etiology
Ie. Hypoalbuminemia
Ie. Leukocytosis with left shift suggesting infection

6. Paracentesis Indications Basic tests Additional tests Diagnostic
New-onset
Suspicion for spontaneous or secondary bacterial peritonitis
Therapeutic
Respiratory compromise
Abdominal pain/pressure
Basic tests
General appearance
Cell count & differential
Total protein
Albumin
Additional tests
Gram stain/culture, LDH, glucose, amylase, cytology, bilirubin
respiratory compromise
Related to abdominal distention
Abdominal pain/pressure
Including abdominal compartment syndrome

7. Analysis Serum-Ascites Albumin Gradient (SAAG)
= (serum albumin) – (ascites albumin)
≥1.1 g/dL  portal HTN
<1.1 g/dL  unlikely portal HTN
Cell count & differential
*best test to assess for infection
PMN > 250/mm3 suggests infection
Correction for bloody tap
WBC correction – subtract 1 WBC for every 750 RBC
PMN correction – subtract 1 PMN for every 250 RBC
SAAG
≥1.1 g/dL  portal HTN
97% accuracy of being related to portal HTN
Can look back at “ascites classification” slide to review etiologies related to portal HTN
Cell count & differential
If PMN > 250/mm3 – recommend starting empiric Abx (pending gram stain/culture)

8. Analysis Utilization of Glucose, LDH, Total Protein
Helps distinguish cardiac from hepatic etiology
Ascitic Fluid Total protein <2.5 g/dL
Suggests hepatic etiology
Ascitic Fluid Total protein ≥2.5 g/dL
Suggests cardiac etiology

9. Summary Most common causes of ascites Indications for Paracentesis
1. Cirrhosis, 2. Malignancy, 3. CHF
Indications for Paracentesis
a) diagnostic (1. new onset; 2. r/o SBP)
b) therapeutic (if ascites is causing symptoms)
Analysis
SAAG
≥1.1 g/dL  portal HTN
<1.1 g/dL  unlikely portal HTN

10. This is a useful algorithm from UpToDate
*don’t have to go through it – just for people to know that this resource is available on UpToDate.

11. MKSAP Questions
A 68-year-old man is evaluated for new-onset ascites with lower-extremity edema. Symptoms have increased gradually over the past 4 weeks. He has consumed three alcoholic beverages per day for many years. His medical history is notable for coronary artery bypass graft surgery 8 months ago and dyslipidemia. His medications are low-dose aspirin, atorvastatin, and metoprolol.
On physical examination, temperature is 36.8 °C (98.2 °F), blood pressure is 122/84 mm Hg, pulse rate is 64/min, and respiration rate is 16/min; BMI is 28. Cardiac examination reveals an elevated jugular venous pressure, a normal S1 and S2, and no murmurs. Pulmonary examination findings are normal. Abdominal examination reveals hepatomegaly, distention, dullness to percussion over the flanks, and a positive fluid wave. There is 2+ pitting edema of the lower extremities.
Laboratory studies reveal a serum albumin level of 3.5 g/dL (35 g/L). Other studies, including serum alanine aminotransferase and aspartate aminotransferase levels, are normal.
Paracentesis reveals a total nucleated cell count of 120/µL with 30% polymorphonucleocytes. Ascitic fluid albumin level is 2.3 g/dL (23 g/L) and total protein is 3.5 g/dL (35 g/L).
Which of the following is the most likely cause of this patient’s ascites?
1. Alcoholic cirrhosis
2. constrictive pericarditis
3. nonalcoholic cirrhosis
4. TB peritonitis

12. MKSAP Question SAAG = 3.5 - 2.3 = 1.2 (>1.1)
A 68-year-old man is evaluated for new-onset ascites with lower-extremity edema. Symptoms have increased gradually over the past 4 weeks. He has consumed three alcoholic beverages per day for many years. His medical history is notable for coronary artery bypass graft surgery 8 months ago and dyslipidemia. His medications are low-dose aspirin, atorvastatin, and metoprolol.
On physical examination, temperature is 36.8 °C (98.2 °F), blood pressure is 122/84 mm Hg, pulse rate is 64/min, and respiration rate is 16/min; BMI is 28. Cardiac examination reveals an elevated jugular venous pressure, a normal S1 and S2, and no murmurs. Pulmonary examination findings are normal. Abdominal examination reveals hepatomegaly, distention, dullness to percussion over the flanks, and a positive fluid wave. There is 2+ pitting edema of the lower extremities.
Laboratory studies reveal a serum albumin level of 3.5 g/dL (35 g/L). Other studies, including serum alanine aminotransferase and aspartate aminotransferase levels, are normal.
Paracentesis reveals a total nucleated cell count of 120/µL with 30% polymorphonucleocytes. Ascitic fluid albumin level is 2.3 g/dL (23 g/L) and total protein is 3.5 g/dL (35 g/L).
Which of the following is the most likely cause of this patient’s ascites?
1. Alcoholic cirrhosis
2. constrictive pericarditis
3. nonalcoholic cirrhosis
4. TB peritonitis
SAAG = = 1.2 (>1.1)
Ascitic Fluid Total Protein: 3.5 (≥ 2.5)
*Both suggest ascites related to portal HTN from cardiac etiology