Makindo Medical Notes.com

Depending on local guidance use dullness to percussion or USS to find an area of free fluid with no other structures that is posterior and dependent. Insert the needle using the Z-track method,

About

• Abdominal paracentesis is a simple bedside or clinic procedure in which a needle is inserted into the peritoneal cavity and ascitic fluid is removed
• Diagnostic paracentesis refers to the removal of a small quantity of fluid for testing.
• Therapeutic paracentesis refers to the removal of five litres or more of fluid to reduce intra-abdominal pressure and relieve the associated dyspnoea, abdominal pain, and early satiety
• Routine measurement of the prothrombin time and platelet count before therapeutic or diagnostic paracentesis and infusion of blood products are not recommended (See references below)

Indications

• Diagnostic paracentesis should be carried out without a delay to rule out SBP in all cirrhotic patients with ascites on hospital admission.
• Ascites and uncertain aetiology

Indications for Procedure

• New onset ascites, Fever, abdominal pain, increasing volume
• Encephalopathy, Renal failure, To Exclude SBP

Contraindications

• Severe Uncorrectable Coagulopathy - raised INR > 1.5 and low platelets < 40
• Intestinal obstruction with bowel distension, Infected abdominal wall

Cautions

• Hyponatraemia < 126 mmol/L, Poor renal function, Hepatic impairment
• Significant anaemia, Albumin < 20, Neutropenia or immune deficient
• Poor patient cooperation, Surgical scarring at the puncture site
• Large intra-abdominal mass
• 2nd or 3rd trimester pregnancy (Needs ultrasound guidance).
• Severe portal hypertension with abdominal collateral circulation as can damage dilated veins in the abdominal wall.

Complications of Procedure

• Haemorrhage due to injury to artery or vein - Intra-abdominal bleeding can be difficult to control and can be fatal.
• Persistent leakage of ascites fluid through the needle puncture site
• Hypotension, Bleeding, Infection, Injury to organs, Infection
• Bowel perforation causing peritonitis and infection of the ascitic fluid
• Hypotension and low Na after large volume paracentesis

Procedure

• Introduction, explain procedure, consent
• Check bloods for coagulopathy (INR > 1.5) or low platelets (< 50)
• Patient should urinate to empty bladder or insert catheter
• Monitor Temp Pulse HR BP and insert IV cannula

Equipment

• Ultrasound (ideally)
• Dressing trolley & sharps bin
• Sterile field and dressing pack
• Sterile gloves
• 2% Chlorhexidine swabs
• Analgesia
• 10mls of 1% or 2% Lidocaine
• Orange (25G) needle (x1)
• Green (19G) needle (x1)
• 10ml and 20ml Syringe (x1)
• 20ml Syringe (x1) with green (19G) needle (x1)
• Specimen containers
• Blood culture bottles
• Dressing

Positioning

• Position the patient supine in the bed with their head resting on a pillow.
• Select an appropriate point on the abdominal wall in the left lower quadrant, lateral to the rectus sheath.
• Clean the site and surrounding area with 2% Chlorhexidine and apply a sterile drape. Create a sterile field.
• Local anaesthesia is given with lidocaine using the orange needle. Both the skin and peritoneum are sensitive. Use a maximum of 10mls of Lidocaine.
• Anaesthetise deeper tissues using the green needle, aspirating as you insert the needle to ensure you are not in a blood vessel. Aspirate 20ml and remove the needle.

Choosing site

• Ultrasound guidance should be considered when available during Large volume paracentesis to reduce the risk of adverse events
• When not available the site is usually kept lateral to the rectus sheath and various diagrams give an idea.
• Puncture sites should be away from scars, tumour masses, distended bowel, bladder, liver or the inferior epigastric artery that runs 5cm on either side of the midline. The best site is in either iliac fossa (but left ideally) at least 10 cm from the midline.
• Percuss the abdomen to find a point of dullness suggesting fluid or Ultrasound can help show a safe area free of bowel.
• The point of insertion should be anaesthetised with a blue/orange needle with lignocaine 1% down to the peritoneum. Insert the needle slowly to help avoid damaging the bowel and use intermittent suction to avoid entering into a blood vessel. There will be a "give" as you enter the peritoneum and gently aspirate fluid.
• For diagnostic paracentesis, withdraw 30-50 ml into the syringe and place the fluid in appropriate tubes and bottles for testing, including blood culture bottles
• For therapeutic paracentesis a Bonanno catheter is used. Do not advance the needle to far but ensure that you are in the peritoneal cavity and can aspirate ascites. Attach the catheter to a collection bag or vacuum bottle using tubing.
• For therapeutic paracentesis, a large volume of fluid is removed. Removal of 5 to 6 L of fluid is generally well tolerated. In some patients, up to 8 L can be removed.
• Colloid replacement, such as concurrent infusion of IV albumin, is often recommended during large-volume paracentesis (e.g., removal of > 5 L) to help avoid significant intravascular volume shift and post-procedure hypotension.
• A 3-way stopcock can be used to control the flow of fluid when changing collection bottles or if a diagnostic sample is needed.
• Remove the needle and apply pressure to the site. Apply a sterile adhesive bandage to the insertion site.

If the midline approach is used ensure the bladder is emptied first

Investigations

• Measure Ascites Albumin and serum albumin and calculate serum ascites albumin gradient (SAAG).
• Send samples for microscopy for WCC
• Send samples for culture
• Send large sample for Cytology

Diagnostics

• The initial ascitic fluid analysis should include total protein concentration and calculation of the serum ascites albumin gradient (SAAG).
• Ascites fluid analysis for cytology, amylase, brain natriuretic peptide (BNP) and adenosine deaminase should be considered based on the pretest probability of specific diagnosis
• Ascitic neutrophil >250/mm³ count remains the gold standard for the diagnosis of SBP
• Ascitic fluid culture with bedside inoculation of blood culture bottles should be performed to guide the choice of antibiotic treatment when SBP is suspected.

Post procedure

• Colloid replacement Albumin (at BNF) (as 20% or 25% solution) should be infused after paracentesis of >5 L is completed at a dose of 8 g albumin/L of ascites removed. (Quality of evidence: high; Recommendation: strong) avoids hypotension and volume shifts
• In HAS 20% there is 200 g per litre so 1 g per 5 ml so 40 ml per litre is given and so for 4-5 Litres then 200 mls is given.
• In patients with SBP and an increased serum creatinine or a rising serum creatinine, infusion of 1.5 g albumin/kg within 6 hours of diagnosis, followed by 1 g/kg on day 3, is recommended. (Quality of evidence: low; Recommendation: weak)

References

• Guidelines on the management of ascites in cirrhosis 2020
• Albumin solution at BNF
• Human albumin in the management of complications of liver cirrhosis