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