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11/13/24, 7\:18 PM Guide | Ascitic tap

Ascitic tap

Table of contents

Introduction

Taking an ascitic tap (diagnostic paracentesis) involves using a needle and syringe to take a sample of ascitic
patient’s abdomen.
This procedure is used to diagnose the cause of ascites and to exclude the presence of spontaneous bacterial peritonitis.

Gather equipment

Gather the appropriate equipment to perform an ascitic tap\:
Sterile gloves
Apron
Dressings pack
Sterile surface (nursing trolley which has been appropriately cleaned)
Syringe (usually 10ml or 20ml)
Green needle (19G)
Sharps container
Chlorhexidine swab (e.g ChloraPrep™)
Specimen container (usually a white top specimen pot)
Sterile dressing

Local anaesthetic

Using local anaesthetic when performing an ascitic tap depends on patient choice. Some patients may opt not to have local
anaesthetic administered as this involves fewer needles. In an OSCE setting, local anaesthetic should always be o
ascitic tap.
If local anaesthetic is being used, additional equipment includes\:
Lidocaine 1% or 2%
Drawing up needle
Orange needle (25G)
Green needle (19G)
20ml syringe

Ultrasound (if available)

Ideally, ultrasound is used to con
possible to perform this procedure without ultrasound.

Introduction

Wash your hands using alcohol gel. If your hands are visibly soiled, wash them with soap and water.
Don PPE if appropriate.
Introduce yourself to the patient including your name and role.
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Con
Explain what the procedure will involve using patient-friendly language\:
“I n e e d t o t a k e a s a m p l e o f
I t w i l l b e t e s t e d i n t h e l a b t o
i n t o y o u r a b d o m e n . I t m a y b e a l i t t l e p a i n f u l , h o w e v e r , i t s h o u l d n o t t a k e l o n g. I c a n a d m i n i s t e r s o m e l o c a l a n a e s t h e t i c t o t h e
a r e a w h i c h w i l l r e d u c e t h e p a i n w h e n I t a k e t h e s a m p l e . T h e r e a r e a f e w r i s k s a s s o c i a t e d w i t h t h i s p r o c e d u r e , t h e s e i n c l u d e
i n f e c t i o n , p a i n b l e e d i n g , a n d v e r y r a r e l y d a m a g e t o t h e s u r r o u n d i n g s t r u c t u r e s i n y o u r a b d o m e n .
”
Gain consent to proceed with an ascitic tap.
Check if the patient has an allergy to local anaesthetic (if requested) or to the skin preparation agent.
Check for any contraindications
Ask the patient if they have any pain before continuing with the clinical procedure.
Ascitic tap contraindications
Infection overlying the intended needle insertion site is a contraindication to performing an ascitic tap. If an infection is
present, select another site on the patient’s abdomen to take the sample.
Other cautions (but not contraindications) include\:
Coagulopathy (INR >2.0)
Platelets \<50
Pregnancy
Organomegaly

Con

Position the patient so that they are lying
Perform an abdominal examination to con
Whilst con
where the volume of ascites is greatest whilst the patient is lying
Ascitic tap location
An ascitic tap is usually performed in the right or left lower quadrant of the abdomen, where the ascitic
accumulates most. Avoid performing the tap too superiorly, due to the risk of injuring the liver or spleen.
It is important to avoid the inferior epigastric artery which runs within the rectus sheath approximately 4-8cm from the
midline.
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How to select the site when performing an ascitic tap
If available\: use ultrasound to assess the location of ascites further and to
Remove equipment from its packaging and place it onto a sterile surface so that it is easily accessible during the procedure.

Prepare the insertion site

Wash your hands and don sterile gloves and an apron.
Clean the insertion site and the surrounding area thoroughly using chlorhexidine solution and allow it to dry.

Perform the ascitic tap

Local anaesthetic

If the patient wishes to have local anaesthetic, prepare and administer lidocaine subcutaneously using an orange needle
(25G) over the planned puncture site (create a bleb). Aspirate to ensure you are not in a blood vessel.
Replace the 25G orange needle with a 19G green needle.
Administer lidocaine deeper into the tissue, aspirating as you go until you get a

Collect a sample of ascitic

Attach a 19G green needle to a 20ml syringe.
Holding the needle perpendicular to the skin, insert the needle into the previously identi
abdomen.
Advance the needle slowly, ensuring you aspirate as you advance.
Advance and aspirate until ascitic
Aspirate 20ml of ascitic
Z-track technique
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The Z-track technique is an alternative technique which can be used to reduce leakage of ascitic
paracentesis.
The skin is stretched approximately 2cm before inserting the needle into the epidermis. The skin is held in this position
whilst the needle is advanced. The skin is then released after the needle has been removed. This technique creates
a non-linear path between the skin and abdominal cavity.
The Z track technique for performing an ascitic tap

Removal of the needle

Withdraw the needle, disconnect it from the syringe and dispose of the needle in a sharps bin.
Apply a sterile dressing to the area.
Place the aspirated ascitic

If unable to aspirate ascitic

Seek senior advice if you are unable to aspirate ascitic
con

To complete the procedure...

Explain to the patient that the procedure is now complete.
Thank the patient for their time.
Document the patient’s details on the specimen containers at the bedside (using either pre-printed or handwritten labels).
Dispose of PPE and other clinical waste into an appropriate clinical waste bin.
Wash your hands.
Document the details of the procedure including\:
Whether local anaesthetic was used
Volume and colour of ascitic
Any immediate post-procedure concerns or complications
Send the ascitic samples to the lab for analysis in an appropriate plastic leak-proof bag with the completed laboratory request
form\:
Cytology
Gram staining
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Microscopy, culture and sensitivity
Albumin, protein, LDH, glucose, white cell count
For more information on interpreting results, see the Geeky Medics guide to ascitic .
Source\: geekymedics.com
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