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Available data suggests colloid / albumin replacement to prevent haemodynamic deterioration after paracentesis is not necessary. However, proceed slowly draining at most 4-6 L over 4 hours or longer.

About

• Ascites is the accumulation of fluid in the peritoneal cavity. Malignancy is the underlying cause in approximately 10% of all cases of ascites.
• Seen with breast, colorectal, endometrial, gastric, ovarian, and pancreatic.

Aetiology

• Peritoneal lymphatic obstruction.
• Low albumin leading to a reduction in oncotic pressure.
• increased capillary permeability.
• increased portal vein pressure with activation of the RAA

Clinical

• Causes abdominal bloating, swelling, pain, nausea and vomiting
• Anorexia, fatigue, peripheral oedema, heartburn and dyspnoea.

Cautions for paracentesis

• Coagulopathy - raised INR > 1.5 and low platelets < 40
• Hyponatraemia < 126 mmol/L
• Poor renal function, Hepatic impairment
• Significant anaemia, Albumin < 20
• Neutropenia or immune deficient

Contraindications

• Local or systemic infection or Low white cell count / neutropenia
• Coagulopathy: platelets < 40x10⁹ /L or INR > 1.4
• Limit paracentesis to 4-6 litres maximum if: Hepatic or renal failure (creatinine >250mmol/L) or Albumin < 30g/L or sodium < 125mmol/L

Investigations

• Blood tests include FBC, U&Es, LFTs, and coagulation screen. During paracentesis monitor U&Es daily.
• Send ascitic fluid for microscopy and culture. Measure serum-to-ascites albumin gradient), total protein, glucose, LDH, and cytology.
• Bacterial culture is particularly important in those with fever or abdominal pain, although it should be noted that peritoneal carcinomatosis can sometimes mimic spontaneous bacterial peritonitis. Initially give antibiotics (see here) when an elevated fluid neutrophil count is detected, but discontinue when it becomes clear (by positive cytology and absence of growth on bacterial culture) that ascites is related to malignancy and not infection.
• Avoid serum CA125 testing as it is often falsely elevated in the presence of ascites. In fact, virtually all patients, including men, with ascites or pleural fluid of any cause have elevated serum level of CA125. In ovarian cancer, CA125 should not be used to monitor response for at least 28 days following a paracentesis.

Management

• Malignant ascites carries a poor prognosis. Management should be aimed at maximising patient comfort and quality of life. Some guidelines recommend checking clotting and platelets which is different to the cirrhosis guidance.
• Options for malignant ascites include diuretic therapy, therapeutic paracentesis and peritoneovenous shunts.
• Oncological interventions may be helpful in ovarian carcinoma and lymphoma. Hormonal therapy may be useful in hormone sensitive malignancies such as some breast cancers.
• Diuretic therapy may help those with a prognosis of over a month depending on renal function.
• Consider Spironolactone 100-400 mg/day. Takes 5 days to respond. Can result in nausea, headache, lethargy, delirium, hyperkalaemia, skin rashes, diarrhoea and hyponatraemia.
• Therapeutic Paracentesis: Can involve removal of several litres of fluid. Fluid may be loculated in Ovarian cancer and so USS may be useful. Ascitic drains should be removed when no longer in use due to the risk of infection.
• Removal of 4-6 litres is usually enough for to give symptomatic relief. Removal of more than 4-6 litres increases the risk of hypovolemia and adverse effects, but may give symptom relief for longer until the ascites reaccumulates
• There is no evidence to support the use of albumin infusions either during or after paracentesis for malignant ascites.
• If the prognosis is short but patient has troublesome symptoms, consider a brief paracentesis of up to 4-6 litres to reduce discomfort. The drainage can be slowly draining 2 litre every 2-4 hours. Clamp the drain in between.
• When the drain is removed a dressing pad or stoma bag can be applied to the drainage site. Any residual leakage usually settles within 2-3 days.
• Indwelling catheters and peritonovenous shunts have been used in patients with a prognosis of >3 months. There is no evidence to date to show added benefit over repeated paracentesis.
• Systemic and intraperitoneal chaemotherapy has been used but, other than in chaemo sensitive ovarian carcinoma and lymphoma, no benefit has been shown.

References

• Paracentesis for Malignant Ascites Procedure
• Guidelines for the Management of Malignant Ascites St Peters Hospice, Bristol
• GUIDELINES FOR THE MANAGEMENT OF MALIGNANT ASCITES IN PALLIATIVE CARE