Ascites
- Normal peritoneal cavity contains <50 mL fluid which is usually not visible on routine abdominal ultrasound.
- Clinically detectable ascites usually requires >1.5 L fluid.
- Most common cause worldwide: Liver cirrhosis (~80–85% cases).
Epidemiology
Among patients with cirrhosis:
- Ascites is the most common complication.
- Approximately 50% develop ascites within 10 years of diagnosis.
- Development of ascites marks transition from compensated to decompensated cirrhosis.
- One-year mortality after development of ascites ≈15–20%.
- Refractory ascites carries ~50% 1-year mortality.
Pathophysiology
1. Portal Hypertension
Increased resistance within liver causes:↑ Portal venous pressure
—Nitric oxide release—Pooling of blood in splanchnic circulation—
Reduced effective arterial blood volume—Activation of:RAAS,Sympathetic nervous system,ADH—Renal sodium and water retention—Ascites formation
2. Hypoalbuminemia
Reduced hepatic albumin synthesis:↓ Plasma oncotic pressure
3. Lymph Overflow Theory
Portal hypertension causes:↑ Hepatic lymph production—>Leakage into peritoneal cavity
Causes of Ascites
Ascites Classification Based on SAAG and Ascitic Fluid Total Protein-(SAAG = Serum Albumin − Ascitic Albumin)
|
SAAG |
Ascitic Fluid Protein |
Mechanism |
Common Causes |
|
High SAAG (≥1.1 g/dL) |
Low Protein (<2.5 g/dL) |
Portal hypertension with sinusoidal leakage of protein-poor fluid |
Cirrhosis (most common), alcoholic liver disease, fulminant hepatic failure |
|
High SAAG (≥1.1 g/dL) |
High Protein (≥2.5 g/dL) |
Portal hypertension with preserved hepatic sinusoidal protein leakage |
Right heart failure, constrictive pericarditis, severe tricuspid regurgitation, Budd-Chiari syndrome, veno-occlusive disease |
|
Low SAAG (<1.1 g/dL) |
Low Protein (<2.5 g/dL) |
Reduced plasma oncotic pressure |
Nephrotic syndrome, protein-losing enteropathy, severe malnutrition (rare) |
|
Low SAAG (<1.1 g/dL) |
High Protein (≥2.5 g/dL) |
Peritoneal inflammation, malignancy, or lymphatic obstruction |
Peritoneal carcinomatosis, tuberculous peritonitis, pancreatic ascites, chylous ascites, mesothelioma, serositis (SLE) |
Clinical Features
Symptoms
Abdominal
- Progressive abdominal distension
- Weight gain
- Early satiety
- Abdominal discomfort
- Bloating
- Fever,tenderness(SBP-spontaneous bacterial peritonitis.)
Respiratory
- Dyspnea
- Orthopnea
Associated Cirrhosis Features
- Jaundice—Encephalopathy—GI bleeding—Muscle wasting
Malignant ascites
- symptoms related to malignancy —weight loss,Sister Mary Joseph nodule
Heart failure — dyspnea, orthopnea, and peripheral edema.
Chylous ascites—diarrhea, steatorrhea, malnutrition, edema, nausea, enlarged lymph nodes, early satiety, fevers, and night sweats.
Physical Examination
Inspection
- Distended abdomen
- Bulging flanks
- Everted umbilicus
- Hernias
Percussion
- Shifting Dullness—Positive when:500 mL fluid present
- Fluid Thrill—Suggests:1.5–2 L fluid
Other Findings
Portal hypertension signs:
- Splenomegaly
- Caput medusae
- Dilated abdominal veins
Imaging
Ultrasound
First-line investigation.
Detects:Cirrhosis,Portal vein thrombosis,HCC
Sonographic Characterization of Ascites
|
Type of Ascites |
POCUS Appearance |
Possible Etiology |
|
Simple Ascites |
Completely anechoic fluid |
Cirrhosis, heart failure, nephrotic syndrome |
|
Complex Non-Septated Ascites |
Internal echoes/debris |
Hemoperitoneum, infection, malignancy |
|
Complex Septated Ascites |
Fibrin strands, septations, loculations |
TB peritonitis, infected ascites, malignancy |
|
Echogenic Ascites |
Dense echoes/clots |
Hemoperitoneum, bowel perforation |
|
Chylous Ascites |
Fine echogenic particles within fluid |
Lymphatic obstruction, malignancy |
Order of Ascitic Fluid Accumulation (Supine Patient)
|
Location |
Relative Dependence |
|
Pelvis (Pouch of Douglas in females / Rectovesical pouch in males) |
Most dependent |
|
Morison’s pouch (Hepatorenal recess) |
Next most dependent upper abdominal recess,highly sensitive-easiest and quickest window to visualize |
CT Abdomen
Useful for:
- Malignancy
- Tuberculosis
- Pancreatic disease
Diagnostic Paracentesis
GOLDEN RULE
Every patient with: New-onset ascites OR Hospitalized cirrhotic with ascites Must undergo diagnostic paracentesis.
Ascitic Fluid Analysis Routine Tests
- Cell Count and Differential-A PMN count ≥250/mm³ indicates spontaneous bacterial peritonitis, although similar findings may occur in pancreatic ascites.
- Albumin
- Total Protein
- Culture—Culture should be inoculated at bedside into: Blood culture bottles Improves yield significantly.
|
Additional Investigation not always indicated |
Clinical Significance |
|
Serum Amylase >1000 U/L or >3× ULN |
Suggests pancreatic ascites due to pancreatic duct leak or pancreatitis. |
|
Mycobacterial Culture |
tuberculous ascites |
|
Ascitic Fluid LDH & Glucose |
Useful in differentiating secondary bacterial peritonitis from SBP. |
|
Milky Ascitic Fluid Appearance |
Suggestive of chylous ascites. |
|
Lipoprotein Electrophoresis |
detect chylomicrons in chylous ascites. |
|
Ascitic Fluid Triglycerides >200 mg/dL |
Diagnostic of chylous ascites. |
|
Ascitic Fluid Triglycerides ≥187 mg/dL |
Newer diagnostic cutoff with ~95% sensitivity and specificity for chylous ascites. |
|
Ascitic Fluid CA-125 |
elevated in cirrhotic ascites and chylous ascites; not specific for malignancy. |
|
Ascitic Fluid Adenosine Deaminase (ADA>39 U/L) |
tuberculous ascites. |
|
Ascitic Fluid Lactate & pH |
Limited utility in |
Management of Cirrhotic Ascites
- Sodium Restriction
Recommended:2 g sodium/day(~88 mmol/day)
Avoid severe fluid restriction unless significant hyponatremia then fluid restriction to 1–1.5 L/day
- Diuretic Therapy(oral)
First-Line Spironolactone Start: 100 mg/day(Maximum:400 mg/day)—First episode, mild ascites → Spironolactone alone acceptable.
Preferred—Combination Therapy to Maintains potassium balance
Spironolactone : Furosemide—-100 : 40 ratio has to be maintained.
- Weight Loss Goals
Without edema:≤0.5 kg/day
With edema:≤1 kg/day
Large Volume Paracentesis (LVP)
Indications
- Grade 3 ascites
- Tense ascites
- Respiratory compromise
- Painful distension
Albumin Replacement
To prevent Paracentesis-induced circulatory dysfunction (PICD) defined as a more than 50% increase in renin activity above baseline. –hyponatremia, renal impairment, or hepatorenal syndrome
Required when:5 L removed then Dose: 6–8 g albumin/L removed
Example: 8 L removed then Albumin: 48–64 g
Ascites Related Complications
Spontaneous Bacterial Peritonitis
Most important infectious complication.
Hepatorenal Syndrome
Functional renal failure due to advanced cirrhosis.
Hepatic Hydrothorax
- Pleural effusion due to transdiaphragmatic migration of ascitic fluid.
- Usually:Right sided
- Chest tubes are generally avoided because of:Massive protein loss,Infection,Renal failure,Mortality.
Umbilical Hernia
Due to increased intra-abdominal pressure.
Abdominal Wall Rupture
“Flood syndrome”Rare but life-threatening.
Refractory Ascites
Ascites that cannot be satisfactorily prevented by medical therapy and requires repeated large-volume paracentesis (LVP).Refractory ascites represents end-stage circulatory dysfunction.
Diagnostic Criteria
1. Intensive Medical Therapy Failure
|
Intervention |
Requirement |
|
Sodium restriction |
<2 g/day sodium (~88 mmol/day) |
|
Spironolactone |
Up to 400 mg/day |
|
Furosemide |
Up to 160 mg/day |
|
Duration |
At least 1 week |
2. Lack of Response
One of the following:
|
Criterion |
Definition |
|
Mean weight loss |
<0.8 kg over 4 days |
|
Urinary sodium excretion |
Less than sodium intake |
3. Early Recurrence
Reappearance of grade 2 or 3 ascites within:≤4 weeks after successful mobilization
Classification
|
Type |
Definition |
|
Diuretic-resistant ascites |
Ascites persists despite maximal tolerated doses of diuretics and sodium restriction |
|
Diuretic-intractable ascites |
Ascites cannot be controlled because diuretics cause complications(Renal dysfunction,Hyponatremia,Hypokalemia)that prevent effective dosing |
Refractory Ascites Management
Repeated LVP + Albumin
Current standard treatment.
TIPS
Ideal Candidates
|
Parameter |
Preferred |
|
Age |
<70 years |
|
Bilirubin |
<3 mg/dL |
|
MELD |
Generally <18–20 |
|
Cardiac function |
Normal |
|
HE |
No recurrent HE |
Absolute Contraindications
- Severe heart failure
- Severe pulmonary hypertension
- Severe tricuspid regurgitation
- Uncontrolled sepsis
- Unrelieved biliary obstruction
Liver Transplantation
Definitive treatment.
Consider in:
- Refractory ascites
- Recurrent SBP
- Hepatorenal syndrome
- MELD elevation
REFERENCE
- Goosenberg E, Kudaravalli P, Samant H. Ascites. [Updated 2025 Nov 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470482/
- Harrison 22nd edition
- Oxford handbook of internal medicine