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Ascitic drain insertion (therapeutic paracentesis)

­­Ideally ascitic procedures should be ultrasound guided

Indications for ascitic drain insertion (therapeutic paracentesis)

  • Refractory ascites secondary to portal hypertension (usually in liver cirrhosis)
  • Palliation in malignant ascites
  • Respiratory embarrassment (secondary to diaphragmatic ‘splinting’)

Equipment required for ascitic drain insertion (therapeutic paracentesis)

  • Ultrasound and ultrasound operator
  • Dressing trolley & sharps bin
  • Sterile field
    • Sterile dressing pack
    • Sterile gloves
    • 2% Chlorhexadine swabs
  • Analgesia
    • 10mls of 1% or 2% Lidocaine
    • Orange (25G) needle (x1)
    • Green (19G) needle (x1)
    • 10ml Syringe (x1)
  • 20ml Syringe (x1)
  • Scalpel
  • Cannula dressing (x2)
  • Paracentesis catheter (Safe-T-centesis®, Bonnano or similar 18G drain)
  • Urinary catheter bag (or similar)
  • Blood culture bottles
  • 20% Human Albumin Solution (HAS)

Contraindications to ascitic drain insertion (therapeutic paracentesis)

  • Local infection
    • Choose another site
  • Cautions – but not contraindications
    • Coagulopathy (INR>2.0)
      • Attempt to correct INR to <1.5 if possible.
    • Platelets<50
      • Thrombocytopenia and coagulopathy is often present in liver disease and though it is a caution, it not a contraindication to paracentesis or drainage
      • The incidence of clinically significant bleeding is low; routine FFP or platelets is not indicated
    • Pregnancy
    • Organomegaly
    • Obstruction/ileus
    • Distended bladder
    • Abdominal adhesions

Potential complications of ascitic drain insertion (therapeutic paracentesis)

  • Sepsis (including secondary bacterial peritonitis)
  • Perforation of viscus or vessels causing haemorrhage (abdominal wall haematoma has been reported in up to 2% in case series)
  • Intra-vascular volume depletion (hypotension) & renal impairment
  • Exacerbation of hepatic encephalopathy


  • Consent patient
    • Infection, bleeding, pain, failure, damage to surrounding structures (especially bowel perforation), leakage
  • Ultrasound to confirm fluid and insertion sight (see ascitic tap pages)
  • Set up sterile trolley

Procedure for ascitic drain insertion (therapeutic paracentesis)

  • Position the patient supine in the bed with their head resting on a pillow.
  • Select an appropriate point on the abdominal wall in the right or left lower quadrant, lateral to the rectus sheath. If a suitable site cannot be found with palpation and percussion consider using ultrasound to mark a spot.
  • Clean the site and surrounding area with 2% Chlorhexadine and apply a sterile drape.
  • Anaesthetise the skin with Lidocaine using the orange needle. Ensure you raise a large bleb as the drain perforating the skin will be the most painful part of the procedure.
  • Anaesthetise deeper tissues using the green needle, aspirating as you insert the needle to ensure you are not in a vessel before infiltrating with lidocaine. Use a maximum of 10mls of Lidocaine.
  • Take the Bonanno catheter and advance needle to tip of catheter, thus straightening it out
  • Insert the paracentesis catheter using a ‘Z’ track
    • Perforate the skin perpendicularly, and then advance obliquely in the sub-cutaneous tissue for 1-2cm before returning to a perpendicular position to puncture the peritoneal cavity.
  • Gradually advance the catheter into the peritoneal space.
  • Once you have inserted the catheter to the equivalent length of the green needle where fluid was first aspirated, start to pull the needle back slowly whilst advancing the catheter.
  • Do not pull the needle back too far as it is needed for stability, but equally do not push the needle too far into the peritoneal cavity.
  • Advance catheter to the hilt and completely remove needle.
  • Fix with two sterile cannula dressings.
  • Affix the drainage bag and leave on free drainage after obtaining the required samples.
    • Microbiology
      • Microscopy, culture & sensitivities (be explicit if yeast or mycobacterium suspected)
      • Culture in blood culture bottles inoculated at the bedside
    • Haematology
      • Automated WCC count (send EDTA sample)
    • Biochemistry
      • Albumin, Protein, LDH, Glucose
      • Remember to send a serum albumin, LDH and glucose at the same time (or at least from the same day).
      • Special tests: Fluid amylase, Triglycerides, Bilirubin
    • Cytology
  • Remove drain after 6 hours if cirrhosis
    • This is due to the high risk of peritonitis
    • Drains for malignant effusions can be left in for longer but the risk of peritonitis still exists


  • Monitor Pulse, BP and Respirations
    • 15 minutes for 1 hour; 30 minutes for 1 hour; And hourly for 4 hours
  • Measure and record drain and urine output
  • Observe for signs of shock or acute haemorrhage
  • In patients with liver cirrhosis do not leave drain in for more than 6 hours
  • In patients with cirrhosis consider infusing human albumin solution for every litre drained – liaise with gastroenterology for advice if needed
    • In portal hypertensive ascites order 20% Human Albumin Solution from the blood bank. Generally 100mls should be infused for each 2000mls of ascites drained.
    • Volume replacement is not routinely required for malignant ascites unless the patient becomes hypotensive during drainage (but suggest 250ml colloid fluid challenge if required).Send fluid for urgent cell count, MC&S, LDH, protein and cytology
  • Send paired LDH and protein serum samples
  • Consider antibiotic cover if SBP is suspected
    • Refer to your trust policy
    • Co-amoxiclav and Tazocin are commonly used

In the event of failure

  • Stop procedure
  • Seek senior help
  • Re-review imaging and patient with a senior colleague to ensure presence of fluid
  • Consider further imaging or ascitic drain insertion in radiology

Top Tips for ascitic drain insertion (therapeutic paracentesis)

  • Inserting a Bonanno catheter requires a similar motion to cannula insertion, it is important not to advance the needle too far but you need to ensure the catheter is passing into the peritoneum without kinking.
  • A Bonanno catheter is actually a form of suprapubic catheter. When ascitic drains are inserted in the radiology department, they will use pigtail catheters
  • In patients with a thick abdominal wall a spinal needle can be used to infiltrate anaesthetic and check position.
  • If you aspirate blood when infiltrating an anaesthetic; stop, withdraw your needle, change position by 1-2cm and try again.
  • If your patient becomes more hypotensive whilst being drained then temporarily clamp the drain and infuse colloid fluid iv (e.g 20% Human Albumin Solution or Gelofusin®).


Bonanno catheter

A Bonanno catheter

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Common ascitic fluid result examples for medical students, finals, OSCEs and MRCP PACES


Click here to download free teaching notes on ascitic drain insertion (therapeutic paracentesis): Procedures – Ascitic drain insertion

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