Diagnostic Ascitic Paracentesis Sampling Technique

Publication: 06/03/2014  
Next review: 12/08/2022  
Standard Operating Procedure
ID: 3738 
Approved By: Trust DTC 
Copyright© Leeds Teaching Hospitals NHS Trust 2019  


This Standard Operating Procedure is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Please check the patients allergy status, as they may be allergic to Chlorhexidine, and alternative ( Providine iodine) solution will be required.
Be aware: Chlorhexidine is considered an environmental allergen.
Refer to the asepsis guidance.

Diagnostic Ascitic Paracentesis Sampling Technique

Background and indications for standard operating procedure/protocol
Procedure method (step by step)
Ascitic Tap Proforma

Background and indications for standard operating procedure/protocol

A diagnostic paracentesis (ascitic tap) should be performed PRIOR to starting antimicrobial therapy within 6 hours in all patients:

  • Presenting with a clinical suspicion of spontaneous bacterial peritonitis (SBP)
  • Presenting with cirrhosis and ascites on hospital admission,
  • on the development of ascites,
  • suffering gastrointestinal haemorrhage,
  • with cirrhosis on the development of any local (abdominal pain, reduced motility) or systemic symptoms (fever, sepsis) or signs (encephalopathy, renal impairment).

Diagnositc ascitic paracentesis is safe.  Minor and major complications are occurring in 1% and <0.1%, respectively.  Minor complications include abdominal haematoma, major complications include bowel perforation.  Coagulopathy is not a contraindication.

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Procedure method (step by step)


1.  Wash hands with soap and water, then dry hands in accordance with LTHT Hand Hygiene in Practice policy and put on disposable apron.

2.  Identify the correct patient e.g. check name band and verbally confirm identity where possible, explain the procedure and obtain verbal consent.  Verbal consent is sufficient but must be documented (see below).

3.  Confirm ascites by examining the patient supine.

4.  Request an abdominal ultrasound if the ascites cannot be demonstrated clinically.

5.  The ultrasound department can perform the ascitic tap (following this SOP) or mark a suitable site on the skin for sampling.

6.  If you have any questions about the technique, the indication, or consent process please contact the on-call Gastroenterology SpR via switchboard.



7.  Perform hand hygiene in accordance with LTHT Hand Hygiene in Practice policy.

8.  Prepare all the equipment you will require.

  • Sterile gloves
  • Apron
  • Trolley
  • Sterile wipes - containing 2% chlorhexidine in 70% isopropyl alcohol
  • Dressing pack
  • Green needle (21G)
  • 2x 20ml syringe
  • Swabs/cotton wool
  • Specimen bottles - 1x EDTA, 1x LiHep, 1x Fluoride/Oxalate, 1x blood culture set, 2x universal tubes

9.  Remove the caps from the blood culture bottles and wipe the bottle tops with a sterile wipe containing 2% chlorhexidine in 70% isopropyl alcohol. Allow to air dry.

10. Open a dressing pack carefully ensuring only the corners are touched with your ungloved hands to create a sterile field on the trolley. Carefully open supplementary equipment and drop onto the sterile field.

11. Disinfect the non sterile rubber tops of blood culture bottles using a swab containing 2% chlorhexidine in 70% alcohol (sani-cloth CHG 2%) and place bottles to the side of the sterile field, not on it.

12. Identify the cutaneous puncture site as follows:

  • Lower abdominal quadrant left or right, avoiding enlarged liver or spleen;
  • Keep 15cms lateral to umbilicus to avoid epigastric arteries.

13. Put on sterile examination gloves while skin disinfectants dry.

14. Attach a green needle (21G) to a 20ml syringe.

15. Clean the site using a 2% chlorhexidine in 70% isopropyl alcohol wipe.  Apply the disinfectant by pressing the swab in the centre of chosen site.) (If necessary infiltrate the aspiration site with 5ml 1% lignocaine.)

16. Perform the ascitic tap and withdraw 25-40ml of ascitic fluid.

17. Place a swab or cotton wool over the site and apply gentle pressure while withdrawing the needle. Press firmly over the site if bleeding occurs.

18. Decant the fluid into the sample tubes as in the table below:

19. Discard needle and syringe into a sharps bin.

20. Write patient details and clinical information on all sample bottles according to Trust policy.

21. Wash hands with soap and water, then dry hands.

22. Arrange transport of the sample to the laboratory.

23. Document procedure in the notes using the proforma including the verbal consent and asepsis.

24. Ensure that sampling details and any subsequent positive results communicated by the laboratories are accurately documented in the patient’s notes and advice is acted on within one hour.

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Record: 3738

To standardise and optimise the diagnostic sampling of ascitic fluid.

Clinical condition:
Target patient group:
Target professional group(s): Secondary Care Doctors
Adapted from:

Evidence base

Evidence levels:

A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus.
D. Leeds consensus. (where no national guidance exists or there is wide disagreement with a level C recommendation or where national guidance documents contradict each other)

Approved By

Trust DTC

Document history

LHP version 1.0

Related information

Not supplied

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