Table Of Contents
Ascites
Ascites refers to the presence of fluid in the peritoneal cavity. It can be due to increased hydrostatic pressure in the portal system, decreased oncotic pressure bdue to hypoalbuminaemia and/or increased permeability of vessels in the abdominal circulation.
Causes of ascites
| Category | Causes |
|---|---|
| Transudative ascites (portal hypertension) | Cirrhosis, congestive heart failure, nephrotic syndrome, budd-chiari syndrome |
| Exudative ascites (increased permeability) | Peritoneal metastases, tuberculous peritonitis, serositis (e.g. lupus) |
- Causes of ascites
- Cirrhosis
- Malignancy
- Heart failure
- Nephrotic syndrome
- Tuberculous peritonitis
- Pathophysiology of ascites
- Increased permeability, portal hypertension or hyoalbuminaemiacauses leakage of fluid into the peritoneum
- Reduced intravascular volume due to loss of fluid into the peritoneal cavity
- Reduced renal blood flow → activation of RAAS, sympathetic system and antidiuretic hormone (ADH)
- Increased aldosterone causes retention of sodium and water → expansion of plasma volume→ further leakage of fluid into the peritoneal cavity
- Investigations (ascitic tap)
- Appearance
- Clear/straw-coloured = cirrhosis
- Cloudy = infection
- Milky = chyluos ascites
- Bloody = malignancy or traumatic tap
- Total ascitic protein
- 2.5 g/dL = exudative
- <2.5 g/dL = transudative
- SAAG: to differentiate between transudative and exudative causes of ascites. SAAG = serum albumin – ascitic fluid albumin
- ≥ 1.1 g/dL: portal hypertension (exudative)
- < 1.1 g/dL: non-portal hypertensive cause (transudative)
- Culture and gram stain: to rule out SBP
- Cytology: for malignancy
- Appearance
- Treatment of ascites
- Fluid restriction to < 1500 ml per day
- Low salt diet
- Monitor U/E/Cs frequently, particularly Na+
- Daily weight monitoring aiming for weight loss of ≤ 500 g per day
- Mineralocorticoid antagonist e.g. spironolactone to counter RAAS which contributes to the ascites
- Furosemide if response to fluid is low
- Paracentesis (ascitic tap or drain): up to 20 L can be drained. Replace with albumin for every litre removed above 5 L
- Prophylactic antibiotics e.g. ciprofloxacin if thre is < 15g/L of protein in the ascitic fluid
- Transjugular intraheptic portosystemic shunt (TIPS) for refractory ascites due to cirrhosis
- Liver transplantation for refractory ascites due to cirrhosis
