Therapeutic abdominal paracentesis (ascitic drain) [advanced]

Before you start

Indications: large volume ascites causing respiratory compromise or abdominal pain/pressure

Relative contraindications: coagulopathy (INR >1.4, platelets <50, therapeutic anticoagulant <24 hours, clopidogrel <7days); pregnancy; distended bowel (obstruction/ileus); organomegaly; distended bladder


  • Wash hands, Introduce self, Patients name & DOB & wrist band, Explain procedure and get written consent
    • Risks: pain; bleeding; infection (peritonitis); damage to local structures (including bowel perforation); paracentesis leak
    • Ask patient to empty their bladder prior to procedure
  • **Check patients clotting screen, platelet count and if they have been on an therapeutic anticoagulant/clopidogrel**
  • Ensure assistant is available
  • Examine patient and tap out ascites
  • Use ultrasound to confirm the presence/location of ascites, check the depth of the abdominal wall and mark the spot pre-procedure

Preparation part

  • Wash hands and apply apron
  • Clean a trolley
  • Gather equipment onto bottom of trolley (think through what you need in order)

Equipment list

  • Sterile pack
  • Cleansing snap-sponge x2 (iodine or alcohol/chlorhexidine)
  • Sterile drape with hole in centre (or 2-3 drapes without holes in)
  • 10ml syringe and 3 needles (1 blunt fill 18G drawing-up needle, 1 orange 25G, 1 green 21G) for local anaesthetic
  • Paracentesis catheter kit – equipment included in kits varies
    • Scalpel
    • Catheter (8Fg) with safety puncture needle, blue valve and attached 3-way tap
    • 20ml syringe
    • Blue valve cap
    • Extension tubing to attach 3-way tap to drainage bag
  • Drainage bag with tubing (can use catheter bag)
  • Cotton gauze swabs (used whenever needed throughout procedure to dry/clean sterile area)
  • Sterile dressing to secure catheter e.g. two cannula dressings
  • Equipment to be kept outside of the sterile field
    • Sterile gloves
    • 10ml 1% lidocaine (maximum 3mg/kg – note 1ml 1% lidocaine = 10mg)
    • Absorbent pads

  • Walk to patient
  • Wash hands
  • Open sterile pack to form a sterile field on the top of the trolley
  • Open packets (without touching the instruments themselves) and drop sterile instruments neatly into the sterile field
  • Pick up waste bag from sterile pack without touching anything else and stick to side of trolley

Patient part

Positioning and exposure

  • Position patient lying supine in bed with head of bed elevated (aids fluid accumulation in lower abdomen)
  • Expose patient’s abdomen

If the insertion point has not already been marked using ultrasound…

  • Locate insertion point:
    • Traditionally in the right iliac fossa (approximately 5cm above and up to 5cm medial to the right ASIS) – right side is strongly preferred because patients may have splenomegaly and splenic varices on left
    • Tap out ascites and confirm flank dullness at intended insertion point
  • Use different site if there is overlying infection
  • Mark insertion point with a skin pen/indentation


  • Wash hands
  • Apply sterile gloves using sterile technique (open pack on a side surface)
  • Sterilize area
    • Work from middle outwards in one spiral motion (using cleansing snap-sponge)
    • Repeat with second cleansing snap-sponge
    • Discard used snap-sponges as they are no longer sterile, but note all equipment used after this (including all needles) can be returned to the sterile field after use
    • Apply the sterile drape over the patient’s body so that the hole is in the correct place to allow access to the insertion site (or apply 2-3 drapes centred around exposed insertion site if no holes)
  • Anaesthetise tract
    • Ask assistant to snap open lidocaine bottle and hold open upside-down
    • Draw up lidocaine using drawing-up needle on 10 ml syringe and expel any air
    • Change to the orange needle and insert at an acute angle to form a single subcutaneous bleb around insertion site in order to anaesthetise the skin
    • Change to the green needle and insert perpendicular to the skin to anaesthetise the insertion tract
      • This is done by instilling lidocaine in small increments of increasing depth
      • Always aspirate when advancing the needle (so you know when you get to the peritoneal cavity) and aspirate before injecting lidocaine (to check you are not in a vessel)
      • When fluid is aspirated, remove needle and do not advance further
  • Now wait 1 minute for the anaesthetic to work, while you prepare the equipment and put in order:
    • Scalpel: expel blade
    • Needle/catheter preparation: attach 20ml syringe to end of needle; close 3-way tap; remove catheter sheath
    • Blue valve cap
    • Extension tubing
Ascitic drain kit


  • Make a 2mm scalpel incision through the anaesthetised skin
  • Insert needle perpendicular to the skin into the same tract, aspirating during infiltration
  • When fluid is aspirated, advance 5-10mm further to ensure the tip of the catheter enters the peritoneal cavity (not just the tip of the needle) – safety needle kits may also click as they enter the peritoneal cavity
  • Holding the needle still, undo the blue valve and advance the catheter off the end of the needle until the flange touches the skin
  • Remove needle
  • Attach the blue valve cap to the blue valve at end of the catheter
  • Secure catheter flange with dressing
  • Attach extension tubing to 3-way tap, then attach drainage bag
  • Open 3-way tap and ensure drainage
  • IF SAMPLES ARE REQUIRED: attach the 20ml syringe used during insertion to the side port of the 3-way tap and aspirate 20ml for samples, then replace bung


  • Secure tubing

To complete

  • Confirm it works
  • Thank patient and cover them
  • Decant and send ascitic fluid samples if collected
  • Bin waste and gloves, dispose of sharps safely, clean trolley and wash hands
  • Fluid replacement: give 100ml 20% human albumin solution following every 2L ascites drained in cirrhotic patients; otherwise determine need for crystalloid fluids clinically
  • Drainage rate: free drainage of up to 5L over first 4 hours, then up to 1L/h (if hypotensive – limit to 0.5L/h throughout)
  • Fully document procedure in patients notes
  • Other notes
    • Drain can be left in for up to 6 hours (risk of infection if left longer, especially for cirrhotic patients)
    • If ascitic fluid is still draining through tract after removal, attach stoma bag
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