1. As a diagnostic procedure to determine the cause of ascites and ascertain cytological diagnosis. It should be kept in mind there are other causes of ascites other than malignancy. It can be helpful to also send ascites to microbiology and biochemistry. It can be useful to have a serum to-ascites Albumin Gradient (SAAG) if the ascites turns out not to be malignant.
2. As a therapeutic procedure: in patients with large volume ascites to provide symptomatic relief.

• Severe bowel distension
• Severe coagulopathy
• Disseminated intravascular coagulation
• Local or systemic infection
• Low white cell count / neutropenia
• Skin infection at the proposed puncture site 
• Distressed/uncooperative patient

The risk associated with paracentesis can be associated with the removal of large volumes (> 6 litres) as this can cause a ‘fluid shift’ with resultant hypovolaemia and hypotension, leading to symptoms of dizziness, fatigue and malaise. Additional procedural risks include; perforation of abdominal viscus, haemorrhage, infection, discomfort. See appendix 1 for risks to be discussed with patient when consenting for procedure.

Drain insertion should be performed under ultrasound guidance or following marking.  Care should be taken particularly if ascitic fluid is not easily clinically identified, there has been difficulty with previous paracentesis, there is suspected loculation of ascites or there are concerns about bowel obstruction.  Consideration should be given to assistance from radiology department where difficulty is anticipated.

• Review up to date FBC, coag, U+Es and LFTs
• Check IV access sited and patent
• Ensure site has been marked if USS guidance not available
• Ensure nursing staff available to assist insertion
• Obtain informed consent
• Patient should empty bladder prior to procedure
• Check full set of observations including – pulse, BP, temperature, respiratory rate and O2 saturations
• Ensure correct equipment available – see appendix 2 for required equipment

• Place patient in semi upright position
• Confirm the presence of ascites
• The usual site for paracentesis is the left side but can be in either iliac fossa at least 10cm from midline or suprapubically (must ensure bladder is empty). The chosen site should avoid: distended bowel or bladder and inferior epigastric arteries. Guided by ultrasound marking if trained.

• Abdomen is prepared with aseptic solution and sterile drape applied
• Infiltrate up to 10ml of 2% lidocaine into the area to be cannulated.
• Using local anaesthetic syringe, needle is inserted through sheath and ascites withdrawn. A larger needle may need to be considered in patients with a high BMI
• When anaesthesia of insertion site achieved small incision made with scalpel and drain needle inserted. Once flashback is visualised, advance the catheter whilst withdrawing the needle.
• If cytology required minimum 200ml should be sent
• It can be useful to consider sending fluid to microbiology and biochemistry, particularly where the ascites turns out not to be malignant. Tests should include  Cell count and differential, Bacterial culture, Albumin (for serum-to-ascites albumin gradient (SAAG)), Total protein, Glucose and LDH.
• Closed drainage system is attached.
• If drain is to remain in situ sutures are inserted and sterile dressing applied.
• Document the procedure, plan for drainage and required frequency of observation in the notes.
• Record full set of observations again and volume drained immediately post procedure

• Record BP, pulse and temperature every 15 minutes for the first hour after insertion, hourly for 4hrs and 4 hourly thereafter if within normal limits
• Monitor fluid balance and urea and electrolytes daily Observe paracentesis insertion site and change dressing daily.
• If the patient becomes unwell, clamp the drain, take pulse, blood pressure and temperature and seek medical advice.
• Aim to remove drain after 48hrs. If continuing to drain significant volumes discuss with medical staff regarding timing of removal

Drainage rate and amount

Most patients will tolerate the procedure well. Total amount drained will depend on the individual patient, the volume of ascites and previous experiences with paracentesis. 

*Signs and symptoms of hypovolaemia: high pulse, low BP; dizziness; increasing fatigue and malaise.

The drain should be clamped after each litre drained and removed once minimal volumes draining. If significant volumes still draining at 48hrs discuss with senior medical staff regarding keeping the drain in situ for ongoing drainage, this should be reviewed by a senior clinician every 24hrs.

For patients where chemotherapy is unlikely to be effective and who require repeated drainage, an indwelling catheter should be considered and should be discussed with the oncology team.