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Abdominal Paracentesis August 2019
Dr Alex Thompson Specialty Trainee in Gastroenterology, NHS Lothian Dr Tom Manship Specialty Trainee in Gastroenterology, NHS Lothian Dr Aaron McGowan Specialty Trainee in Gastroenterology, NHS Lothian Dr Tim Cartlidge Specialty Trainee in Cardiology, NHS Lothian Dr Anna Stout Clinical Teaching Fellow, NHS Lothian Dr Oliver Daly Consultant Anaesthetist, NHS Lothian Dr James Tiernan Consultant Physician, NHS Lothian Dr Simon Edgar Director of Medical Education, NHS Lothian Dr Caroline Bates Consultant in Acute and GI Medicine, NHS Lothian Dr Mike Williams Consultant Hepatologist, NHS Lothian
Therapeutic paracentesis refers to the medical procedure for draining ascitic fluid to alleviate
the symptoms caused by tense ascites. This is also referred to as large volume paracentesis,
(LVP) if more than 5L is drained.
It is most commonly used in the setting of cirrhosis in a specialist GI/liver ward but it can also
performed in patients with malignant ascites.
This is a procedural competency requirement for several postgraduate curricula.
Indications
1. Relief of symptoms associated with large volume ascites e.g. abdominal discomfort
or breathlessness
2. Treatment of refractory ascites i.e. diuretic resistant or diuretic intolerant
Risk Assessment: Paracentesis
Potential Contraindications (discussed further on next page):
1. Anticoagulation
2. Patient factors increasing technical difficulty
3. Haemodynamic instability
4. Acute renal impairment
5. Procedural timing
Risk Assessment: Paracentesis (cont.)
Anticoagulation:
• A prolonged prothrombin time (PT) is a common finding in cirrhotic patients as a result of
impaired synthetic liver function and reduced production of clotting factors. However, as
these patients also have reduced production of anticoagulant factors, a prolonged PT does
not equate to an increased bleeding risk. There is therefore no need to correct a
prolonged PT prior to an ascitic tap.
• Similarly, low platelets are common in cirrhosis and ascitic taps can safely be performed
in patients with platelets >20. If the platelet count is less than 50 you should seek senior
advice about the risks and benefits of a platelet transfusion.
• In contrast, anticoagulation with warfarin or direct-acting oral anticoagulants (DOACs)
does increase bleeding risk and these should be withheld or reversed if possible. An ascitic
drain should be avoided in patients with disseminated intravascular coagulation.
Patient Factors:
• A confused/agitated patient increases the technical challenge and should prompt
consideration of whether a more experienced practitioner is available to perform the
procedure. A diagnostic aspiration is often still required if there is suspicion of SBP, with
encephalopathy, however, a therapeutic drainage would rarely be urgently indicated in
such circumstances.
• Other physical patient factors can increase the technical challenge of performing an ascitic
tap. These include obesity, significant organomegaly, and previous abdominal surgery
with the risk of adhesions and loculation of ascites. Again, an experienced practitioner
should be involved, and consideration given to ultrasound guidance.
• Pregnancy, abdominal skin infection at the proposed puncture sites, and severe bowel
distension are usually contraindications to an ascitic tap.
Haemodynamic instability
• Large volume paracentesis can result in profound fluid shifts and circulatory compromise
over the subsequent 12-24 hours. This can result in a reduction of effective blood volume,
or ‘post-paracentesis circulatory dysfunction’ (PPCD). Clinical manifestations include
acute kidney injury, dilutional hyponatraemia, and hepatic encephalopathy. LVP should
therefore be conducted with intravenous plasma volume expansion: 100ml of 20%
albumin solution, for every 3L ascites removed. If patients have previously had PPCD or
there are concerns about hypovolaemia, this can be increased to 100ml for every 2L
ascites drained.
Acute renal impairment
• Due to the risk of PPCD, therapeutic paracentesis is often best avoided at a time of acute
kidney injury, and delayed until renal function has recovered. However if needed, LVP can
be performed in this situation but close monitoring of fluid and haemodynamic status is
critical. Renal biochemistry and urine output should be monitored closely peri-procedure.
Diuretics are usually withheld for 24-48 hours following drainage.
Procedure timing
• Therapeutic drainage is very unlikely to be necessary outwith normal working hours, and
to do this could be unsafe; as there tends to be fewer experienced staff for post-
procedural monitoring and less senior nursing or medical cover should complications
arise. The main exception would be hypoxia secondary to tense ascites, with or without
an associated hepatic hydrothorax.
Post-procedural care
• This is crucial to safety following paracentesis.
• The nursing team caring for the patient should be experienced in looking after ascitic
drains.
• Ascitic drains should be removed as soon as they have finished draining and ideally within
6-8 hours of insertion, due to the risk of infection.
• Clear verbal communication to nursing staff, and written documentation about plasma
volume replacement and timing of drain removal is paramount.
Complication Recommended Action
Abdominal haematoma
(1-3%) Reassurance, simple analgesia
Persistent leak
(3-5%)
Lie on opposite side
Apply adhesive drainage bag, reassure that likely
to resolve quickly
Hypotension IV colloid challenge
Acute kidney injury Monitor, omit nephrotoxic drugs, IV colloid
replacement
Encephalopathy
Consider causes including electrolyte disturbance
or infection, likely to benefit from IV colloid and
bowel evacuation
Secondary infection
Maintain index of suspicion and re-tap if clinical
concern, low threshold for antibiotics. Risk
increased with prolonged length of time drain in
situ.
Haemoperitoneum
(<0.1%)
Monitor for circulatory compromise/ haemoglobin
drop. Volume replacement, correct coagulopathy,
seek senior support. May require cross-sectional
imaging e.g. CT angiogram
Viscus (bowel or bladder) perforation
(<0.1%)
Seek senior support and surgical review. Likely to
require cross-sectional imaging.
Accidental drain removal If partially or fully withdrawn should not be
reinserted, assess need for repeat procedure
The incidence of complications increases with severity of liver disease, according to the Child-Pugh classification, and with alcohol-related cirrhosis in particular.
Ascites is the accumulation of excess fluid within the peritoneal cavity. This usually becomes
clinically detectable when there is more than 1L of fluid although >20L can ultimately collect
within the peritoneal cavity.
Abdominal distension should be investigated by percussion for flank dullness, and assessment
for “shifting dullness” by rolling the patient onto their side.
Upon suspicion of first presentation with ascites, the person should undergo abdominal
imaging, in the form of Ultrasound or CT, to confirm presence of ascites before interventional
procedures.
Surface Anatomy
There are 3 preferred safe sites for performing an ascitic tap, as illustrated below. These sites
are selected as those least likely to result in injury to either major blood vessels (especially
the inferior epigastric arteries) or internal organs.
Figure 1: potential paracentesis sites marked with ‘X’ along with representation of the normal course of the inferior epigastric arteries (Adapted from Thomsen et al, 2006)
1. Left and right lower quadrants: 3cm above and 3cm medial to the anterior superior iliac spine (ASIS)
represents a site where the abdominal wall is usually thin and the fluid pool is often deep.
The left side is generally preferred to the right as it avoids the caecal pole and any potential
hepatosplenomegaly (as both organs enlarge towards the RIF).
2. Midline: 3cm below the umbilicus represents a site with a low risk of bleeding as the linea alba is
generally avascular.
Pathophysiology
Cirrhosis is the most common cause of ascites and accounts for approximately 80% of cases.
The onset of ascites is a major landmark in the natural history of cirrhosis and is associated
with a worsening in prognosis.
In cirrhotic ascites, there is also a risk of bacterial translocation across the gut barrier resulting
in spontaneous bacterial peritonitis (SBP). This may present in a non-specific manner, and
some patients may not have either fever or abdominal pain. SBP is often associated with an
acute kidney injury and carries a relatively high mortality. For these reasons, it is crucial to
assess for SBP in a cirrhotic patient with ascites and any clinical deterioration. The British
Society of Gastroenterology cirrhosis care bundle recommends that an ascitic tap is
performed within 6 hours of admission in all patients with cirrhosis and ascites.
Ascitic Fluid Analysis
The appearance of ascitic fluid can provide useful clues. Ascites is usually clear and straw-
coloured. It may become turbid in the presence of infection, or blood-stained in malignancy
(or following a previous paracentesis). Chylous ascites appears milky and suggests impaired
lymphatic drainage.
The analysis of ascitic fluid plays an essential role in determining the underlying aetiology of
new onset ascites.
Routine tests Rarer tests (in specific situations)
Albumin Amylase (if suspected pancreatic cause)
Protein Cytology (if clinical suspicion of malignancy)
White cell count AFB smear / culture (if suspicion of TB)
C&S (blood culture bottles) Triglyceride (if chylous)
Bilirubin (if suspected bile leak eg post-surgical)
As with pleural effusions, one of the primary aims is to distinguish transudate from exudate.
This distinction is best made by using the serum ascites-albumin gradient (SAAG) which is
calculated as a simple subtraction:
SAAG = serum albumin - ascitic albumin
A value of ≥11g/L is consistent with ascites secondary to portal hypertension (see table
below).
Serum ascites-albumin gradient >11 g/l Serum ascites-albumin gradient < 11 g/l Cirrhosis Malignancy Cardiac failure Pancreatitis Tuberculosis (Nephrotic syndrome) (Nephrotic syndrome)
Low protein (total protein <15g/L) ascites is a risk factor for SBP and should prompt
consideration of long-term antibiotics as primary prophylaxis against infection.
Ascitic white cell count and fluid culture are key investigations in patients with cirrhosis. A
polymorphonuclear leucocyte count >250/mL indicates the presence of bacterial infection.
Inoculating some ascitic fluid into blood culture bottles at the bedside improves the yield of
an organism from 40-50% to 70-80%.
Other relevant biochemical tests may include amylase (>1000U/L suggests pancreatic ascites)
and bilirubin (>6mg/dL might suggest a post-operative bile leak). A sample should be sent for
cytology in cases where peritoneal malignancy is suspected. However, as the diagnostic yield
is relatively low, larger volumes of fluid may be required.
Equipment + Resources
• Competent supervisor
• Skilled assistant
• Clean trolley, waste disposal and sharps bin
• Absorbent pads
• Sterile gloves and apron
• Iodine or chlorhexidine-based antiseptic solution
• Sterile dressing pack including gauze, liquid container and drape
• Local anaesthetic (1 or 2% lignocaine)
• 10ml and 20ml syringes
• Blunt (18G) needle for drawing up local anaesthetic
• Green (21G) and orange (25G) needles for administering local anaesthetic
• Scalpel (optional)
• Ascitic drain pack (Bonano catheter): introducer needle, drain, connector/clamp
• Universal containers + Blood culture bottles
• Drainage bag, non-collapsible tubing and drain stand
• Adhesive dressings for anchoring drain to skin (e.g. tegaderm cannula dressings)
Exclude contraindications
Check whether known allergies
Examine patient – note organomegaly, scars of previous surgery
Review platelet count, biochemistry and any recent imaging
Check for anticoagulant medications
Review diuretic prescription
Preparation
Ensure patient has emptied bladder
Ensure patient has a working peripheral cannula
Lie patient supine, head elevated 20-30 degrees
Place an absorbent pad under the patient
Ensure assistant prepared
Identify and mark planned site for tap (e.g. with blunt needle cap)
(3cm above and 3cm medial to Left ASIS)
Arrange equipment (non-touch technique – assistant can perform this)
Open sterile pack onto procedural trolley
Open procedural equipment onto pack
Ensure trolley on correct side for clinician
Aseptic Conditions
Wearing apron, wash hands and put on sterile gloves
Apply antiseptic skin preparation to patient
Drape the area
Allow skin to dry
Local Anaesthetic
Check description and expiry date with assistant and draw-up local anaesthetic.
Infiltrate local anaesthetic subcutaneously with 25G (orange) needle to form a bleb.
Z-technique’: Hold the local anaethetic syringe in one hand, with the tip at the appropriate
site of insertion. Use the other hand to pull the skin down by 1-2cm prior to advancing the
needle. (see figures below and video slides)
Inject local anaesthetic deeper with a 21G (green needle), always aspirating first and moving
from superficial to deep layers, until able to aspirate ascitic fluid
Prepare drain catheter whilst anaesthetic taking effect – insert introducer needle, remove
plastic sheath and attach 20ml syringe to end of device.
Clamp the connecting tubing.
Make a small skin incision with a scalpel to aid smooth insertion of the drain (optional)
‘Z-technique’: Using the same technique as for the local anaesthetic, enter the peritoneal
cavity with the needle tip. This ensures that when the drain is removed, the holes in the
skin, muscle and peritoneum are not overlying one another and it reduces fluid leakage.
Advance the drain slowly whilst gently aspirating the syringe until there is loss of resistance
and free aspiration of fluid indicating entry into the peritoneal cavity
If gas is aspirated, this indicates passage of the needle into bowel.
The procedure must be stopped and urgent senior advice obtained.
Advance a further 1cm to ensure that the tip of the drain is well within the peritoneal cavity
Advance drain catheter over the introducer needle whilst keeping the needle in a fixed
position, until the anchor is flush with the skin.
Take care not to pull the introducer needle back too early as this can cause displacement
of the drain.
Remove the introducer needle completely
Connect a 20mL syringe to collect a sample for cell count, then place safely aside
Connect the Luer lock end of the (clamped) rubber tubing to the drain
Connect the rubber tubing to the drainage bag
Secure drain anchor with adhesive dressings and open clamp to allow free flow
Attach drainage bag onto drain stand and place below level of bed
Inoculate fluid into blood culture bottles and universal containers
Dispose of waste and sharps appropriately
Label and send samples to:
Microbiology for cell count and culture
Biochemistry for albumin and protein
Pathology if malignancy suspected
Paired serum should be sent for albumin
Document the procedure, including any immediate complications and results
• Ideally use an electronic menu to prompt high standard documentation
Post-procedure care
• SEWS and volume drained should be measured regularly – at least hourly
• 100ml intravenous 20% HAS should be given for every 3 litres of ascites drained
• Remove drain after 6 - 8 hours or when no longer draining
Mastery Assessment Procedural Checklist References
Mastery Assessment Procedural Checklist Abdominal Paracentesis
Date: Name: Grade: Tutor: Session: Hospital: Unit:
Skill Phase + Component Start Yes
Start No
End Yes
End No
Phase 1 – Preparation + Positioning
**Identifies correct patient and lists contra-indications
**List core consent topics
**Lists essential equipment + ensures trained assistant present
Describes optimal position (supine + arm raised)
Optimises ergonomics (bed height / spread of equipment)
**Identifies and marks insertion site (3cm + 3cm from ASIS)
Phase 2 – Procedural Pause
**Performs final equipment check
Performs 3-point check: Patient, Assistant and Clinician
Phase 3 – Asepsis + Anaesthesia
**Puts on Apron + Sterile Gloves
**Applies antiseptic skin wash + allows to dry (non-touch)
**Drapes the patient (non- touch +/- tape by assistant)
Infiltrates local anaesthetic
Phase 4 – Insertion
**Safely inserts needle (double-handed, pincer grip)
Aspirates to confirm entry into peritoneum
Obtains ascitic fluid samples (at least 20ml)
Advances drain catheter over introducer and removes introducer needle
Connects drain catheter to tubing and drainage bag
Phase 5 – Anchoring + Dressing
Describes securement of drain with adhesive dressings
Describes attachment of drainage bag onto drain stand
Phase 6 – Completion + Global Points
Describes aftercare: Samples / Albumin / Documentation
** Maintains control of needle throughout
**Demonstrates safe sharps management throughout
**Maintains asepsis throughout
Demonstrates effective communication with assistant throughout
Total Score (out of 24) / 24 / 24
Summative Assessment Y N **All critical safety items passed? Final score ≥ 21? Would you be content for this learner to proceed to directly supervised clinical practice? Ask the learner; would they be content to proceed to directly supervised clinical practice?
• YES to all items: Proceed to Directly Supervised Clinical Practice o
• NO to any item: Return for another session o
Comments
Moore KP, Aithal GP. Guidelines on the management of ascites in cirrhosis. Vol. 55 Suppl 6, Gut. 2006, pp.vi1-12. Runyon BA; Management of adult patients with ascites due to cirrhosis: an update. AASLD Practice Guidelines Committee. Hepatology. 2009 Jun;49(6):2087-107. Thomsen TW, Shaffer RW, White B, Setnik GS. Paracentesis. N Engl J Med 2006;355:e21 European Association for the Study of the Liver. EASL Clinical Practice Guidelines for the management of patients with decompensated cirrhosis. J Hepatol. 2018 Aug;69(2):406-60 McPherson S, Dyson J, Austin A, Hudson M. Response to the NCEPOD report: development of a care bundle for patients admitted with decompensated cirrhosis- the first 24h. Frontline Gastroenterol. 2016 Jan;7(1):16-23. Scottish Government (2000). Adults with incapacity (Scotland) Act 2000. Edinburgh. Available at: http://www.scotland.gov.uk/Topics/Justice/law/awi