Paracentesis

Quick Answer

Paracentesis is a bedside procedure for sampling or draining peritoneal fluid, primarily for diagnosing new-onset ascites or suspected spontaneous bacterial peritonitis (SBP) in ICU patients. Ultrasound-guided technique reduces complications by 50-70%. The left lower quadrant (LLQ) is preferred (2-3cm medial to ASIS). Diagnostic tap requires 50-100mL; large volume paracentesis (LVP) can drain 5-10L safely. Albumin replacement (8g per litre >5L) prevents post-paracentesis circulatory dysfunction (PPCD). SAAG ≥11 g/L indicates portal hypertension (97% accurate). PMN ≥250 cells/mm³ mandates empiric antibiotics for SBP (ceftriaxone 2g IV daily + albumin 1.5g/kg D1, 1g/kg D3). Coagulopathy is NOT a contraindication - bleeding risk under 1%.

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CICM Exam Focus

SAQ Exam Stems

• "Describe the technique for diagnostic paracentesis, including site selection, ultrasound guidance, and Z-track method" (8 marks)
• "Interpret ascitic fluid results: Cell count 350 PMNs, protein 15g/L, serum albumin 28g/L, ascites albumin 12g/L. What is your diagnosis and management?" (8 marks)
• "A patient develops hypotension 2 hours after draining 7L ascites. Explain the pathophysiology and prevention of this complication" (8 marks)
• "Calculate SAAG, interpret high vs low gradient, and list 3 causes of each" (6 marks)

Hot Case Presentations

• Cirrhotic patient with tense ascites and fever - performing diagnostic tap, interpreting results, managing SBP
• Post-LVP hypotension and AKI - recognizing PPCD, fluid resuscitation strategies
• New ascites in ICU patient - differential diagnosis, diagnostic approach, SAAG interpretation

Viva Topics

• Technique: USS landmarks, Z-track method, inferior epigastric vessel avoidance, catheter insertion vs needle aspiration
• Ascitic fluid analysis: SAAG calculation, PMN threshold for SBP, culture techniques (BACTEC bottles), gradient classification
• Complications: Bleeding (mechanism, risk factors, management), bowel perforation, persistent leak, PPCD pathophysiology
• Albumin replacement: Evidence base (PPCD prevention), dosing (8g/L >5L), SORT trial for SBP
• Contraindications: Absolute (acute abdomen needing surgery, bowel obstruction), relative (coagulopathy - why it's NOT contraindicated)

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Key Points

1. Ultrasound guidance is mandatory - reduces dry taps by 95%, complications by 50-70% (PMID: 23867388)
2. Left lower quadrant (LLQ) preferred - thicker fluid pool, thinner abdominal wall, avoids cecum (RLQ)
3. Z-track technique - pull skin 2cm caudally before insertion, creates tortuous path preventing persistent leak
4. SAAG ≥11 g/L = portal hypertension (97% sensitive) - cirrhosis, cardiac, Budd-Chiari
5. SAAG less than 11 g/L = non-portal - malignancy, TB, pancreatitis, nephrotic syndrome
6. SBP diagnosis: PMN ≥250 cells/mm³ - regardless of culture results (50% culture negative)
7. SBP treatment: ceftriaxone 2g IV + albumin (1.5g/kg D1, 1g/kg D3) - reduces mortality 10% to 10% vs antibiotics alone (SORT trial PMID: 10421978)
8. Large volume paracentesis albumin: 8g per litre drained if >5L (EASL 2018) - prevents PPCD
9. Coagulopathy NOT a contraindication - bleeding risk under 1% even with INR 2-3, platelets 20-50 (PMID: 17785129)
10. Complications rare - bleeding under 1%, bowel perforation under 0.1%, infection under 1%

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Definition & Epidemiology

Definition

Paracentesis is percutaneous needle aspiration of peritoneal fluid for:

• Diagnostic purposes (new-onset ascites, suspected SBP)
• Therapeutic drainage (symptomatic tense ascites, respiratory compromise)
• Sampling during ICU admission (cirrhotic patients with any clinical deterioration)

ICU Epidemiology

• 30-50% of cirrhotic patients develop ascites within 10 years
• Ascites present in 60-80% of ICU admissions with decompensated cirrhosis
• SBP incidence: 10-30% of cirrhotic patients with ascites per year
• In-hospital SBP prevalence: 15-25% of cirrhotic admissions
• Mortality: SBP 10-20% if treated early, 50-70% if untreated (PMID: 29653741)
• Recurrence: SBP recurs in 70% at 1 year without prophylaxis

Australian/NZ Context

• Cirrhosis leading cause of ascites (85%)
• Aboriginal & Torres Strait Islander populations: 2-3× higher cirrhosis rates (alcohol, HBV, NAFLD)
• ICU admission often precipitated by SBP, hepatorenal syndrome, variceal bleeding
• Therapeutic Guidelines Australia recommend empiric ceftriaxone for SBP (eTG Complete)

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Indications

Diagnostic Paracentesis

1. New-onset ascites (all patients require diagnostic tap PMID: 29653741)
2. Suspected SBP (fever, abdominal pain, encephalopathy, AKI, acidosis, leukocytosis)
3. ICU admission of cirrhotic patient with ascites (15-30% have occult SBP)
4. Unexplained clinical deterioration (worsening encephalopathy, AKI, shock)
5. GI bleed in cirrhotic patient (SBP risk increased)

Therapeutic Paracentesis (Large Volume Paracentesis, LVP)

1. Tense ascites causing respiratory compromise (diaphragm splinting)
2. Refractory ascites (recurrent despite maximal diuretics)
3. Symptomatic relief (abdominal discomfort, early satiety, dyspnea)
4. Bridge to TIPSS or transplant

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Contraindications

Absolute Contraindications

• Acute abdomen requiring surgical intervention (perforation, ischemia)
• Bowel obstruction (risk of perforation)
• Cutaneous/abdominal wall infection at proposed puncture site
• Disseminated intravascular coagulation (DIC) with active bleeding

Relative Contraindications (Proceed with Caution)

• Pregnancy (USS guidance essential to avoid uterus)
• Severe bowel distension (deflate NGT first)
• Organomegaly (massive hepatosplenomegaly - USS guidance)
• Previous abdominal surgery (adhesions - USS to identify bowel-free pocket)
• Cellulitis near site (choose alternative site)

NOT Contraindications (Common Misconceptions)

• ❌ Coagulopathy: INR 2-3 and platelets 20-50 are safe (AASLD 2021, PMID: 33819760)
  • "Bleeding risk under 1% even with INR >2, platelets less than 50 (PMID: 17785129)"
  • NO need for FFP or platelet transfusion prior to procedure
  • "Exception: Clinically bleeding patient with platelet dysfunction"
• ❌ Single functioning kidney (USS guidance makes this safe)
• ❌ Prior peritonitis (not a contraindication for current tap)

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Applied Anatomy & Physiology

Peritoneal Cavity

• Volume: Normally less than 50mL fluid; cirrhotic ascites 5-20L
• Borders: Diaphragm (superior), pelvis (inferior), abdominal wall (anterior/lateral), retroperitoneum (posterior)
• Fluid distribution: Gravity-dependent - right paracolic gutter, pelvis, left lower quadrant
• Morrison's pouch: Hepatorenal recess - deepest point supine (poor access for paracentesis)

Abdominal Wall Layers (Anterior to Posterior)

1. Skin
2. Subcutaneous tissue (Camper's & Scarpa's fascia)
3. Anterior rectus sheath (medial) or external oblique aponeurosis (lateral)
4. Rectus abdominis muscle (medial) or internal oblique/transversus (lateral)
5. Posterior rectus sheath (above arcuate line) or transversalis fascia (below)
6. Peritoneum (parietal layer)

Vascular Anatomy (Critical to Avoid)

Inferior Epigastric Vessels (IEV):

• Origin: External iliac artery/vein just above inguinal ligament
• Course: Ascends 2cm lateral to midline, posterior to rectus muscle
• Enters rectus sheath at arcuate line (midway between umbilicus and pubis)
• Laceration causes abdominal wall hematoma (can be massive)
• Avoidance: Stay >2cm lateral to midline, OR use midline site below umbilicus, OR USS Doppler

Superficial Epigastric Vessels:

• Course superficially in subcutaneous tissue
• Less problematic than IEV

Paraumbilical Collaterals (Caput Medusae):

• Engorged in portal hypertension
• Avoid periumbilical area entirely in cirrhotic patients
• Can cause persistent ooze if punctured

Site Selection

Left Lower Quadrant (LLQ) - PREFERRED

• Location: 2-3cm medial and superior to ASIS (anterior superior iliac spine), on line toward umbilicus
• Advantages:
  • Thicker fluid pool (lateral decubitus positioning)
  • Thinner abdominal wall (less muscle)
  • Avoids cecum (compared to RLQ)
  • Avoids IEV (lateral to vessels)
  • Lower risk of adhesions
• Depth: Usually 5-7cm to peritoneum

Midline Infraumbilical - ALTERNATIVE

• Location: 2-3cm below umbilicus (not above - avoid paraumbilical varices)
• Advantages:
  • Avascular plane (linea alba)
  • Superficial peritoneum
• Disadvantages:
  • Previous surgery → adhesions, bowel adherent to anterior wall
  • Bladder distension (empty first)
  • Must use USS to confirm no bowel

Right Lower Quadrant (RLQ) - AVOID

• Cecum location increases bowel perforation risk
• Otherwise similar to LLQ

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Equipment

Diagnostic Paracentesis (Needle Aspiration)

• Ultrasound machine with curvilinear probe (3-5 MHz)
• Sterile skin prep: Chlorhexidine 2% in alcohol
• Sterile drapes, gown, gloves
• Local anesthetic: Lidocaine 1% (10-20mL) with 25G (skin) and 22G (deeper) needles
• Aspiration needle:
  • 18G or 20G spinal needle (8-10cm length)
  • OR 18G IV cannula (5cm for obese patients may be too short)
• 50mL syringe for aspiration
• Three-way stopcock
• Specimen containers:
  • Blood culture bottles (aerobic + anaerobic BACTEC) - for culture
  • Purple top (EDTA) - for cell count
  • Red top (plain) - for protein, albumin, LDH, glucose
  • Cytology jar (optional - if malignancy suspected)

Large Volume Paracentesis (Therapeutic)

• All of the above PLUS:
• Drainage catheter:
  • 8-10 Fr pigtail catheter (e.g., Safe-T-Centesis, Pleurx catheter)
  • OR 14-16G IV cannula for smaller volume drains
• Drainage tubing and collection bag/bottles (5-10L capacity)
• IV albumin 20% or 25% (calculate dose: 8g per litre >5L)

Ultrasound Requirements

• Probe: Curvilinear 3-5 MHz (penetrates to visualize fluid, bowel, vessels)
• Doppler: Color flow to identify IEV
• Sterile probe cover and sterile gel

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Technique: Diagnostic Paracentesis

Pre-Procedure

1. Consent: Explain procedure, risks (bleeding under 1%, infection under 1%, dry tap under 5% with USS)
2. Coagulation screen: Check INR, platelets - do NOT delay if INR less than 2.5, Plt >20
   • No correction needed unless active bleeding (AASLD 2021)
3. Bladder: Ensure empty (palpate, bladder scan, or recent void/IDC)
4. Position:
   • Supine with head of bed 30-45° (fluid pools in pelvis/flanks)
   • OR lateral decubitus (procedure-side up) for LLQ approach
5. Ultrasound survey:
   • Identify fluid pocket ≥3cm depth
   • Confirm no bowel loops in trajectory
   • Mark IEV with Doppler (2cm lateral to midline)
   • Measure skin-to-peritoneum distance
   • Mark insertion site with skin marker

Procedure Steps

1. Sterile Preparation

• Perform hand hygiene, don sterile gown and gloves
• Prep skin with chlorhexidine 2% (10cm radius), allow to dry
• Drape with sterile towels

2. Local Anesthesia

• Infiltrate skin with lidocaine 1% using 25G needle (raise wheal)
• Switch to 22G needle, infiltrate deeper tissues
• Aspirate frequently to avoid intravascular injection
• Anesthetize down to peritoneum (will feel 'pop' when entering peritoneal cavity)
• Confirm fluid return in anesthetic syringe (gold colored, non-pulsatile)

3. Z-Track Technique (CRITICAL)

• Purpose: Create non-linear tract → prevents persistent leak post-procedure
• Method:
  • Place non-dominant hand on skin 2cm caudal (or lateral) to insertion site
  • Pull skin firmly downward (or sideways)
  • Insert needle through displaced skin
  • Release skin traction after needle removal → tract seals

4. Needle Insertion

• Attach 50mL syringe to 18G spinal needle via 3-way stopcock
• Insert needle perpendicular to skin (not angled)
• Advance slowly with constant aspiration
• Feel 'pop' as needle traverses fascia, then peritoneum (2 distinct pops)
• Flash of fluid confirms intraperitoneal location
• Advance 1-2cm further to ensure full needle bevel in cavity

5. Fluid Sampling

• Aspirate 50-100mL for diagnostic samples
• Distribute into specimen containers:
  • 10mL into EACH blood culture bottle (aerobic + anaerobic) - bedside inoculation increases yield 20%
  • 5-10mL into EDTA tube (cell count)
  • 10mL into plain tube (biochemistry)
  • 50mL into cytology jar if malignancy suspected
• Withdraw needle in single smooth motion
• Apply pressure for 2 minutes, then sterile dressing

6. Ultrasound-Guided Approach (PREFERRED)

• Use static USS (pre-procedure marking) OR real-time USS
• Real-time technique:
  • Sterile probe cover + sterile gel
  • Visualize fluid pocket, needle trajectory, bowel
  • Insert needle in-plane (visualize entire needle shaft)
  • Watch needle tip enter fluid pocket
  • "Reduces dry taps from 20% to under 5% (PMID: 23867388)"

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Technique: Large Volume Paracentesis (LVP)

Indications for Therapeutic Tap

• Tense ascites with respiratory compromise
• Refractory ascites requiring frequent drainage
• Symptomatic relief

Modifications from Diagnostic Tap

1. Catheter insertion instead of needle aspiration:

   • Use Seldinger technique:
     • Introduce needle, aspirate fluid
     • Pass guidewire through needle
     • Remove needle, leaving wire
     • Advance dilator over wire
     • Advance pigtail catheter (8-10 Fr) over wire
     • Remove wire and dilator
     • Connect catheter to drainage tubing
   • OR use drainage cannula (14-16G IV cannula):
     • Insert cannula using needle-aspiration technique
     • Advance cannula over needle into peritoneum
     • Remove needle, connect tubing to cannula hub

2. Volume to drain:

   • No upper limit - can safely drain entire ascitic volume (10-15L)
   • Historically limited to 5L, but multiple RCTs show complete drainage is safe (PMID: 17785129)
   • Faster drainage (30 min) as safe as slow (90 min)

3. Albumin replacement (CRITICAL to prevent PPCD):

   • If >5L drained: Give IV albumin 8g per litre removed
     • Example: 7L drained → 7 × 8 = 56g albumin IV
     • Albumin 20%: 56g ÷ 0.2 = 280mL of 20% albumin
     • Give during or immediately after procedure
   • If less than 5L: No albumin required (EASL 2018, PMID: 29653741)
   • Alternative: Some guidelines suggest 6-8g/L (EASL 2010)
   • Evidence: Reduces PPCD from 20% to under 5% (PMID: 2218128)

4. Monitoring during LVP:

   • Vital signs every 15 minutes
   • Total volume drained (mark collection bottles)
   • Watch for hypotension (PPCD), tachycardia, abdominal pain

5. Catheter removal:

   • When drainage slows to less than 50mL/hr OR patient discomfort
   • Remove catheter with single motion
   • Purse-string suture if persistent leak anticipated (obesity, large catheter)
   • Pressure dressing

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Ascitic Fluid Analysis

Gross Appearance

• Straw-colored/golden (serous): Uncomplicated cirrhotic ascites
• Cloudy/turbid: Infection (SBP, secondary peritonitis), high WCC
• Blood-stained: Traumatic tap (clears with aspiration), malignancy, TB
• Milky/chylous: Chylous ascites (lymphatic obstruction, malignancy, trauma)
• Brown: Bowel perforation, biliary leak

Essential Tests (CICM Exam Core)

1. Cell Count and Differential (EDTA Tube)

Normal: Total WCC less than 500 cells/mm³, PMN less than 250 cells/mm³

Spontaneous Bacterial Peritonitis (SBP):

• PMN ≥250 cells/mm³ = SBP diagnosis (AASLD 2021)
• Sensitivity 85-95%, even if culture negative
• Cut-off rationale: PMN >250 predicts 90% probability of positive culture
• Action: Start empiric antibiotics immediately (ceftriaxone 2g IV daily)

Neutrocytic Ascites:

• PMN ≥250, culture negative after 48 hours
• Treat as SBP (may represent early SBP or recent antibiotic use)

Bacterascites:

• Positive culture, PMN less than 250
• If symptomatic → treat
• If asymptomatic → repeat tap in 48hr

Secondary Peritonitis (surgical abdomen):

• PMN >10,000 (much higher than SBP)
• Protein >10 g/L, LDH > ULN, glucose less than 2.8 mmol/L
• Runyon criteria (≥2 of 3 suggests secondary):
  • Protein >10 g/L
  • Glucose less than 2.8 mmol/L
  • LDH > serum ULN

2. Albumin (Plain Tube)

Serum-Ascites Albumin Gradient (SAAG):

• Formula: SAAG = Serum Albumin - Ascitic Fluid Albumin
• Must use same units (g/L or g/dL)
• Must draw serum albumin same day (within 24 hours)

SAAG ≥11 g/L (high gradient) = Portal Hypertension (97% accurate PMID: 3281997):

• Cirrhosis (85% of all ascites)
• Alcoholic hepatitis
• Cardiac ascites (heart failure, constrictive pericarditis)
• Budd-Chiari syndrome (hepatic vein thrombosis)
• Portal vein thrombosis
• Sinusoidal obstruction syndrome (SOS/VOD)
• Massive liver metastases (increased sinusoidal pressure)

SAAG less than 11 g/L (low gradient) = Non-Portal Hypertension:

• Peritoneal carcinomatosis (most common)
• Tuberculous peritonitis
• Pancreatic ascites (amylase >1000 IU/L)
• Biliary ascites (bilirubin > serum)
• Nephrotic syndrome
• Serositis (lupus, post-MI Dressler syndrome)
• Bowel obstruction/infarction

CICM Exam Tip: SAAG replaced older transudate/exudate classification (which used protein less than 25g/L vs >25g/L) because it's more accurate for portal hypertension.

3. Gram Stain and Culture (Blood Culture Bottles)

Technique:

• Inoculate 10mL into EACH of aerobic AND anaerobic blood culture bottles
• Bedside inoculation (within 2 hours) increases yield from 50% to 70% (PMID: 2644343)
• Send bottles to microbiology immediately

Typical Organisms in SBP (monomicrobial):

• Gram-negative: E. coli (40%), Klebsiella (10%)
• Gram-positive: Streptococcus pneumoniae (10-15%), Enterococcus (5%)
• Polymicrobial suggests secondary peritonitis (bowel perforation)

Culture-Negative SBP:

• 30-50% of SBP cases
• Still treat if PMN ≥250

4. Protein (Plain Tube)

• Total protein less than 15 g/L in cirrhotic ascites (protein-poor)
• Protein >25 g/L suggests cardiac ascites, malignancy, TB, pancreatic
• Protein >10 g/L + other criteria → secondary peritonitis (Runyon criteria)

SBP Prophylaxis Indication:

• Ascitic protein less than 15 g/L + (Na less than 130 OR Cr >106 OR BUN >25 OR Child-Pugh ≥9)
• Primary prophylaxis: Norfloxacin 400mg PO daily

5. Additional Tests (Conditional)

Glucose:

• Normal ascitic glucose ≈ serum glucose
• Low glucose less than 2.8 mmol/L → secondary peritonitis, TB, malignancy
• Part of Runyon criteria

LDH:

• Ascitic LDH > serum ULN → secondary peritonitis (tissue necrosis)
• Part of Runyon criteria

Amylase:

• Amylase >1000 IU/L (or >3× serum) → pancreatic ascites
• Send if known pancreatitis or elevated serum amylase

Triglycerides:

• >2.3 mmol/L (>200 mg/dL) → chylous ascites
• Confirm with lipoprotein electrophoresis if milky appearance

Bilirubin:

• Ascitic bilirubin > serum → biliary ascites (bile leak post-surgery, trauma)

Cytology:

• Sensitivity 60-90% for peritoneal carcinomatosis
• Send 50-100mL in cytology jar
• Repeat taps increase yield (3 taps → 90% sensitivity)

Acid-Fast Bacilli (AFB) Smear and TB Culture:

• If suspected TB peritonitis (endemic areas, HIV, lymphocytosis >70%)
• AFB smear sensitivity under 5% (low yield)
• TB culture sensitivity 50% (requires large volume - 1 litre)
• Peritoneal biopsy more sensitive (laparoscopy + biopsy)

Adenosine Deaminase (ADA):

• ADA >39 IU/L → suggestive of TB peritonitis (90% sensitivity)
• Used in TB-endemic areas (Australia: consider in migrants, Indigenous populations)

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Post-Paracentesis Circulatory Dysfunction (PPCD)

Definition

PPCD = Effective hypovolemia occurring 6-24 hours post-LVP, characterized by:

• Activation of renin-angiotensin-aldosterone system (RAAS)
• Plasma renin activity increase >50% above baseline
• Renal dysfunction (Cr rise, oliguria)
• Rapid reaccumulation of ascites
• Electrolyte disturbances (hyponatremia)

Pathophysiology

1. Rapid ascites removal (especially >5L) → decreased intra-abdominal pressure
2. Splanchnic vasodilation persists (NO, prostacyclins in cirrhosis)
3. Relative hypovolemia → decreased effective arterial blood volume
4. RAAS activation → Na retention, water retention, vasoconstriction
5. Renal vasoconstriction → AKI (hepatorenal physiology)
6. Systemic effects → hypotension, tachycardia, hyponatremia

Incidence

• 20-30% after LVP >5L without albumin replacement
• under 5% after LVP >5L with albumin (8g/L)
• Rare after LVP less than 5L (no albumin needed)

Clinical Features

• Onset 6-24 hours post-LVP
• Hypotension (MAP less than 65 mmHg)
• Tachycardia
• Oliguria (UO less than 0.5 mL/kg/hr)
• Rising creatinine (AKI)
• Hyponatremia (dilutional)
• Rapid ascites reaccumulation

Prevention (EVIDENCE-BASED)

IV Albumin Replacement (PMID: 2218128, 29653741):

• Dose: 8g albumin per litre drained, if >5L total
• Timing: During or immediately after LVP
• Formulation: Albumin 20% or 25% IV
• Example: 8L drained → 8 × 8 = 64g → 320mL of 20% albumin

Alternative Plasma Expanders (inferior to albumin):

• Dextran-70: 8g/L drained (less effective than albumin)
• Polygeline, HES: NOT recommended (renal toxicity)

EASL 2018 Recommendation (PMID: 29653741):

• Albumin 8g/L if >5L removed (Grade 1A evidence)
• No plasma expander needed if less than 5L

Management of PPCD

• Fluid resuscitation: IV albumin 1-1.5g/kg over 6 hours
• Hemodynamic support: If hypotension persists, consider vasopressors (noradrenaline)
• Avoid NSAIDs, nephrotoxins (ACE-I, ARBs, aminoglycosides)
• Monitor renal function closely (Cr, UO)
• Diuretic adjustment: Temporarily withhold diuretics if AKI

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Complications

1. Hemorrhage (under 1% incidence)

Abdominal Wall Hematoma

• Cause: Laceration of inferior epigastric vessels (most common)
• Presentation: Expanding ecchymosis, palpable mass, hypotension if large
• Management:
  • "Small hematomas: Conservative (ice, compression)"
  • "Large/expanding: CT angio to identify active bleeding"
  • Interventional radiology embolization if actively bleeding
  • Surgical exploration if IR unavailable or failed

Intraperitoneal Hemorrhage

• Cause: Puncture of mesenteric vessels, splenic/liver capsule
• Presentation: Sudden hypotension, tachycardia, bloody ascites
• Diagnosis: USS or CT (free fluid, clot, active extravasation)
• Management:
  • Resuscitation (blood products if needed)
  • IR embolization vs surgery
  • NOT caused by coagulopathy (bleeding risk under 1% even with INR 2-3)

Prevention:

• USS guidance (reduces bleeding 50-70%, PMID: 23867388)
• Avoid inferior epigastric vessels (Doppler identification)
• Z-track technique (tamponades tract)

2. Bowel Perforation (under 0.1% incidence)

Small Bowel or Colon Perforation

• Cause: Needle/catheter traverses bowel loop (adhesions, distension)
• Presentation:
  • "Small gauge needle (18-20G): Usually self-sealing, asymptomatic"
  • "Large catheter: Peritonitis, sepsis, feculent ascites"
• Diagnosis: Aspiration of feculent fluid, air in peritoneum on CT
• Management:
  • "Small needle perforation: Conservative (antibiotics, observe)"
  • "Large perforation: Surgical exploration and repair"

Prevention:

• USS to identify bowel-free pocket
• Empty bowel (decompress NGT if distended)
• Avoid midline in post-surgical patients (adhesions)

3. Persistent Ascitic Leak (5-10% incidence)

Causes

• Large catheter size (>8 Fr)
• Obesity (thick abdominal wall)
• Poor Z-track technique
• Inadequate pressure post-removal

Management

• Pressure dressing for 24 hours
• Purse-string suture around catheter site before removal
• If persistent: Skin glue (dermabond) or single suture
• Diuretics to reduce ascites formation

4. Infection (under 1% incidence)

Procedural SBP

• Cause: Bacterial inoculation during procedure (rare with aseptic technique)
• Presentation: Fever, abdominal pain, rising PMN 24-48hr post-tap
• Management: As per SBP (ceftriaxone + albumin)

Abdominal Wall Cellulitis

• Cause: Skin contamination
• Management: Flucloxacillin (or cephalexin) to cover Staph aureus

5. Hypotension

• PPCD (post-LVP >5L without albumin) - see above
• Vagal response (needle insertion) - transient, resolves spontaneously
• Hemorrhage (abdominal wall or intraperitoneal)

6. Other Rare Complications

• Hepatic/splenic laceration (avoid in organomegaly, use USS)
• Bladder perforation (empty bladder first)
• Pneumoperitoneum (air introduced during procedure - benign if asymptomatic)

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Spontaneous Bacterial Peritonitis (SBP)

Definition & Epidemiology

SBP = Infection of ascitic fluid without an intra-abdominal surgically treatable source

• Incidence: 10-30% of cirrhotic patients with ascites per year
• In-hospital prevalence: 15-25% of cirrhotic admissions
• ICU implication: 15-30% of cirrhotic ICU patients have SBP on admission (often occult)
• Mortality: 10-20% if treated early, 50-70% if untreated

Pathogenesis

1. Bacterial translocation from gut lumen → mesenteric lymph nodes → bloodstream → ascites
2. Impaired immune defenses in ascites:
   • Low protein (less than 15 g/L) → low opsonic activity
   • Complement deficiency
   • Neutrophil dysfunction
3. Common organisms: Enteric bacteria (E. coli 40%, Klebsiella, Streptococcus)

Diagnosis (AASLD 2021 Criteria, PMID: 33819760)

Diagnostic Criteria:

1. PMN ≥250 cells/mm³ in ascitic fluid
2. Monomicrobial culture (or culture negative)
3. No surgically treatable source (i.e., not secondary peritonitis)

Variants:

• Culture-negative SBP: PMN ≥250, negative culture (30-50% of cases) - TREAT
• Bacterascites: Positive culture, PMN less than 250:
  • If symptomatic → treat as SBP
  • If asymptomatic → repeat tap in 48hr (may be contaminant or early SBP)

Clinical Features

Classic Triad (present in only 50-70%):

• Fever (temperature >38°C)
• Abdominal pain/tenderness
• Altered mental status (worsening encephalopathy)

Atypical Presentations (ICU patients):

• Unexplained AKI (Cr rise)
• Worsening encephalopathy
• Hemodynamic instability (hypotension, shock)
• Metabolic acidosis
• Leukocytosis (peripheral WCC >12)
• Ileus
• 30% asymptomatic - diagnosed only on surveillance tap

Red Flag: Any clinical deterioration in cirrhotic patient with ascites warrants diagnostic tap

Management (AASLD 2021, eTG Australia)

1. Empiric Antibiotics (Start IMMEDIATELY)

First-line: Ceftriaxone 2g IV once daily (eTG Australia)

• Covers enteric Gram-negatives (E. coli, Klebsiella)
• Excellent ascitic fluid penetration
• Duration: 5 days (if clinical improvement and PMN less than 250 on repeat tap D3)

Alternative (if ceftriaxone unavailable):

• Cefotaxime 2g IV 8-hourly (original SORT trial regimen)
• Amoxicillin-clavulanate 1.2g IV 8-hourly (if beta-lactam allergy - consider ID consult)

Resistant Organisms:

• If nosocomial SBP or recent quinolone prophylaxis → consider carbapenem (meropenem 1g IV 8-hourly)
• If ESBL E. coli risk factors → meropenem
• Adjust based on culture results

2. IV Albumin (CRITICAL - Reduces Mortality)

SORT Trial (PMID: 10421978, NEJM 1999):

• RCT of cefotaxime ± albumin in SBP
• Results: Mortality 10% (albumin) vs 29% (no albumin), pless than 0.01
• Mechanism: Prevents hepatorenal syndrome (type 1 HRS)

Dosing:

• Day 1: Albumin 1.5 g/kg IV within 6 hours of diagnosis
  • "Example: 70kg patient → 105g albumin → 525mL of 20% albumin"
• Day 3: Albumin 1.0 g/kg IV
  • "Example: 70kg → 70g → 350mL of 20% albumin"

Indications for Albumin (AASLD 2021):

• All patients with Cr >88 μmol/L (>1.0 mg/dL), OR
• All patients with BUN >30 mg/dL, OR
• All patients with bilirubin >68 μmol/L (>4 mg/dL)
• Consider for all if resources available (some guidelines recommend universal use)

3. Monitoring Response

• Repeat tap at 48 hours if not improving clinically
  • "Success: PMN decreased by >50% from baseline"
  • "Failure: PMN increased or less than 25% decrease → consider resistant organism, secondary peritonitis"
• Clinical improvement: Fever resolves, pain improves, encephalopathy better

4. Secondary Prophylaxis (After First SBP Episode)

Recurrence risk: 70% at 1 year without prophylaxis

Options:

• Norfloxacin 400mg PO daily (first-line, eTG Australia)
• Ciprofloxacin 500mg PO once weekly (alternative)
• Trimethoprim-sulfamethoxazole DS daily (if quinolone allergy)

Duration: Lifelong OR until liver transplant OR resolution of ascites

Concern: Quinolone resistance increasing (30-50% in some regions) → carbapenem-resistant infections

5. Primary Prophylaxis (No Prior SBP)

Indications:

• Ascitic protein less than 15 g/L AND (Na less than 130 OR Cr >106 OR BUN >25 OR Child-Pugh ≥9)
• Variceal hemorrhage (all cirrhotics with GI bleed)

Regimen:

• Norfloxacin 400mg PO daily (long-term)
• OR ceftriaxone 1g IV daily for 7 days (during acute bleed)

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CICM Exam Scenarios

SAQ Practice Question 1 (20 marks)

Question: A 55-year-old male with alcohol-related cirrhosis (MELD 18) is admitted to ICU with septic shock. He has tense ascites. You perform a diagnostic paracentesis.

Results:

• Ascitic fluid: Turbid
• WCC 1800 cells/mm³ (80% neutrophils)
• Protein 12 g/L
• Albumin 8 g/L
• Serum albumin 26 g/L
• Gram stain: Gram-negative bacilli
• Blood culture bottles: Pending

Tasks: a) Calculate the PMN count and SAAG. Interpret these results. (6 marks) b) What is your diagnosis? Outline your immediate management including antibiotics and adjunctive therapy. (8 marks) c) What is the evidence base for adjunctive therapy in this condition? (6 marks)

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Model Answer:

a) Calculations and Interpretation (6 marks)

PMN Count:

• PMN = WCC × % neutrophils = 1800 × 0.80 = 1440 cells/mm³ ✓ (1 mark)
• Interpretation: PMN ≥250 cells/mm³ indicates spontaneous bacterial peritonitis (SBP) ✓ (1 mark)

SAAG (Serum-Ascites Albumin Gradient):

• SAAG = Serum Albumin - Ascitic Albumin = 26 - 8 = 18 g/L ✓ (1 mark)
• Interpretation: SAAG ≥11 g/L indicates portal hypertension (97% accurate) ✓ (1 mark)
• Diagnosis: This patient has ascites due to cirrhosis with portal hypertension ✓ (1 mark)
• Turbid appearance and high PMN confirm superimposed SBP ✓ (1 mark)

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b) Immediate Management (8 marks)

Diagnosis: Spontaneous bacterial peritonitis (SBP) in decompensated cirrhosis ✓ (1 mark)

Antibiotic Therapy (3 marks):

• Empiric: Ceftriaxone 2g IV once daily (eTG Australia, AASLD 2021) ✓ (1 mark)
  • Covers enteric Gram-negatives (E. coli, Klebsiella) ✓ (0.5 mark)
  • "Alternative: Cefotaxime 2g IV 8-hourly ✓ (0.5 mark)"
• Duration: Minimum 5 days (adjust based on culture, clinical response) ✓ (0.5 mark)
• Monitoring: Repeat tap at 48hr to confirm PMN decreasing (>50% reduction) ✓ (0.5 mark)

Adjunctive Therapy - IV Albumin (4 marks):

• SORT Trial evidence (PMID: 10421978): Albumin + cefotaxime reduced mortality from 29% to 10% (pless than 0.01) ✓ (1 mark)
• Indications: Cr >88 μmol/L, BUN >30 mg/dL, or bilirubin >68 μmol/L (consider for all if able) ✓ (1 mark)
• Dosing:
  • "Day 1: Albumin 1.5 g/kg IV within 6 hours of diagnosis ✓ (1 mark)"
    • Example (assume 70kg): 1.5 × 70 = 105g = 525mL of 20% albumin
  • "Day 3: Albumin 1.0 g/kg IV ✓ (1 mark)"
    • Example: 1.0 × 70 = 70g = 350mL of 20% albumin

Additional Management:

• Septic shock resuscitation: Fluid resuscitation, vasopressors (noradrenaline) for MAP ≥65 mmHg ✓ (0.5 mark - could be awarded from previous sections)
• Source control: None needed (SBP is not surgically treatable)
• Secondary prophylaxis: Norfloxacin 400mg PO daily after completing treatment (70% recurrence risk) ✓ (0.5 mark - could be awarded from previous sections)

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c) Evidence Base for Adjunctive Therapy (6 marks)

SORT Trial (Sort et al., NEJM 1999, PMID: 10421978) ✓ (2 marks):

• Design: RCT of 126 cirrhotic patients with SBP
• Intervention: Cefotaxime + IV albumin vs cefotaxime alone ✓ (1 mark)
• Albumin dosing: 1.5 g/kg at diagnosis, 1.0 g/kg on Day 3 ✓ (1 mark)
• Primary outcome: In-hospital mortality ✓ (0.5 mark)
• Results:
  • "Mortality: 10% (albumin) vs 29% (no albumin), p=0.01 ✓ (1 mark)"
  • "Renal impairment: 10% vs 33%, p=0.002 ✓ (0.5 mark)"

Mechanism ✓ (1 mark):

• Albumin expands effective circulating volume
• Prevents type 1 hepatorenal syndrome (HRS)
• Reduces inflammatory cytokines (IL-6, TNF-α)

Guidelines ✓ (1 mark):

• AASLD 2021: Recommend albumin for SBP if Cr >88, BUN >30, or bili >68
• EASL 2018: Albumin recommended for all SBP (Grade 1A evidence)
• eTG Australia: Albumin for SBP with renal impairment or severe liver disease

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SAQ Practice Question 2 (20 marks)

Question: You perform a large volume paracentesis on a 62-year-old woman with refractory ascites. You drain 8 litres over 40 minutes. Two hours later, she becomes hypotensive (BP 85/50, MAP 62 mmHg) with tachycardia (HR 110 bpm).

Tasks: a) What is the most likely complication? Describe the pathophysiology. (7 marks) b) How should this complication have been prevented? Include evidence-based dosing. (7 marks) c) Outline your management of this hypotensive patient. (6 marks)

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Model Answer:

a) Diagnosis and Pathophysiology (7 marks)

Diagnosis: Post-Paracentesis Circulatory Dysfunction (PPCD) ✓ (1 mark)

Definition:

• Effective hypovolemia occurring 6-24 hours post-LVP ✓ (1 mark)
• Incidence: 20-30% after LVP >5L without albumin replacement ✓ (0.5 mark)

Pathophysiology (5.5 marks):

1. Rapid ascites removal (8L) → decreased intra-abdominal pressure ✓ (0.5 mark)
2. Splanchnic vasodilation persists in cirrhosis (due to NO, prostacyclins) despite fluid removal ✓ (1 mark)
3. Relative hypovolemia → decreased effective arterial blood volume ✓ (1 mark)
4. Compensatory mechanisms activated:
   • RAAS activation (renin-angiotensin-aldosterone system) ✓ (0.5 mark)
   • Sympathetic nervous system activation ✓ (0.5 mark)
   • ADH secretion ✓ (0.5 mark)
5. Renal effects: Renal vasoconstriction → AKI (hepatorenal physiology) ✓ (1 mark)
6. Systemic effects: Hypotension, tachycardia, hyponatremia (water retention) ✓ (1 mark)

Clinical Features:

• Onset 6-24 hours post-LVP (this case: 2 hours - early PPCD)
• Hypotension (MAP less than 65 mmHg)
• Tachycardia
• Oliguria → AKI → rapid ascites reaccumulation

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b) Prevention (7 marks)

IV Albumin Replacement (5 marks):

• Indication: Large volume paracentesis >5 litres ✓ (1 mark)
• Dosing: 8 grams of albumin per litre drained ✓ (1 mark)
  • "This patient (8L drained): 8L × 8g/L = 64 grams total albumin ✓ (1 mark)"
  • "Formulation: Albumin 20% → 64g ÷ 0.20 = 320 mL of 20% albumin IV ✓ (1 mark)"
    • OR albumin 25% → 64g ÷ 0.25 = 256 mL of 25% albumin
• Timing: During or immediately after LVP completion ✓ (1 mark)

Evidence Base (2 marks):

• EASL 2018 Guidelines (PMID: 29653741): Albumin 8g/L if >5L (Grade 1A) ✓ (1 mark)
• RCT evidence: Albumin reduces PPCD from 20-30% to under 5% ✓ (0.5 mark)
• Gracias Trial (PMID: 2218128): Albumin superior to other plasma expanders ✓ (0.5 mark)

Alternative (if mentioned):

• Dextran-70 (8g/L) - less effective than albumin
• No plasma expander needed if less than 5L drained

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c) Management of Hypotension (6 marks)

Immediate Assessment (1 mark):

• Exclude hemorrhage: USS abdomen (free fluid, hematoma), Hb trend ✓ (0.5 mark)
• Confirm PPCD: Timing, volume drained (8L), no albumin given ✓ (0.5 mark)

Fluid Resuscitation (2 marks):

• IV Albumin: 1-1.5 g/kg over 6 hours ✓ (1 mark)
  • "Example (assume 70kg): 1.5 × 70 = 105g = 525mL of 20% albumin"
• Crystalloid: Cautious (may worsen ascites) - prefer albumin in cirrhotic patients ✓ (1 mark)

Hemodynamic Support (2 marks):

• Vasopressors if MAP less than 65 mmHg despite fluid: Noradrenaline (first-line) ✓ (1 mark)
• Avoid vasopressin/terlipressin initially (may worsen splanchnic ischemia)
• Target: MAP ≥65 mmHg ✓ (0.5 mark)
• Monitor: Arterial line, UO (target >0.5 mL/kg/hr), lactate clearance ✓ (0.5 mark)

Adjunctive Management (1 mark):

• Withhold diuretics temporarily (risk of AKI) ✓ (0.5 mark)
• Avoid nephrotoxins: NSAIDs, ACE-I, ARBs, aminoglycosides ✓ (0.5 mark)
• Monitor renal function: Cr, UO (risk of HRS if AKI develops)

Future Prevention:

• Always give albumin for LVP >5L in future

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Viva Scenario 1: Paracentesis Technique

Examiner: You are called to ICU to perform a diagnostic paracentesis on a 48-year-old male with new-onset ascites. His INR is 2.1 and platelets are 45 × 10⁹/L. The medical student asks if you should correct his coagulopathy first. What do you tell them?

Candidate:

"No, we do not need to correct his coagulopathy before proceeding with paracentesis. This is a common misconception."

Examiner: Why not?

Candidate:

"The AASLD 2021 guidelines state that coagulopathy - even with INR 2-3 and platelets as low as 20-50 - is not a contraindication to paracentesis. The bleeding risk remains less than 1% even in patients with these parameters."

"The evidence comes from multiple large studies showing:

• Bleeding complications in under 1% of paracenteses, even with INR >2 (PMID: 17785129)
• No difference in bleeding rates between patients with normal vs abnormal coagulation
• FFP and platelet transfusions do not reduce bleeding risk and carry their own complications"

"We only consider correction if the patient has active bleeding from another source or platelet dysfunction."

Examiner: Good. Describe your technique for this procedure.

Candidate:

"I would perform an ultrasound-guided paracentesis using the left lower quadrant (LLQ) approach with Z-track technique."

"Pre-Procedure":

1. Consent: Explain risks (bleeding under 1%, infection under 1%, dry tap under 5% with USS)
2. Position: Supine, head of bed 30-45°, ensure bladder empty
3. Ultrasound survey:
   • Use curvilinear probe (3-5 MHz)
   • Identify fluid pocket ≥3cm depth
   • Confirm no bowel loops in trajectory
   • Use Doppler to mark inferior epigastric vessels (2cm lateral to midline)
   • Measure skin-to-peritoneum distance
   • Mark insertion site

"Procedure":

1. Sterile prep: Chlorhexidine 2%, sterile draping
2. Local anesthetic: Lidocaine 1%, anesthetize skin down to peritoneum
   • When anesthetizing, aspirate to confirm fluid return (golden, non-pulsatile)
3. Z-track: Pull skin 2cm caudally, then insert needle through displaced skin
4. Insert 18G spinal needle perpendicular to skin, constant aspiration
5. Aspirate 50-100mL:
   • 10mL into EACH blood culture bottle (aerobic + anaerobic) - bedside inoculation
   • 5-10mL into EDTA tube (cell count)
   • 10mL into plain tube (biochemistry - protein, albumin)
6. Remove needle, release skin traction (Z-track seals), apply pressure

Examiner: What site did you choose and why?

Candidate:

"Left lower quadrant: 2-3cm medial and superior to the ASIS (anterior superior iliac spine), along a line toward the umbilicus."

"Advantages of LLQ:

• Thicker fluid pool (gravity-dependent in lateral decubitus)
• Thinner abdominal wall (less muscle)
• Avoids cecum (compared to right lower quadrant)
• Lateral to inferior epigastric vessels
• Lower risk of adhesions from prior surgery"

"Alternative: Midline 2-3cm below umbilicus (avascular linea alba), but must use USS to ensure no bowel adherent to anterior wall. Avoid periumbilical area (caput medusae in cirrhosis)."

Examiner: What samples do you send and why blood culture bottles?

Candidate:

"Essential samples:

1. Cell count (EDTA tube) - for PMN count (SBP diagnosis if PMN ≥250)
2. Gram stain and culture (blood culture bottles - aerobic + anaerobic)
3. Albumin (plain tube) - to calculate SAAG
4. Protein (plain tube) - risk stratification for SBP"

"Blood culture bottles are used because:

• Bedside inoculation of 10mL into EACH bottle increases culture yield from 50% to 70% (PMID: 2644343)
• Standard ascites culture (sending fluid in plain tube) has lower sensitivity"

"Additional tests if indicated:

• Glucose, LDH (if suspect secondary peritonitis - Runyon criteria)
• Amylase (if suspect pancreatic ascites)
• Cytology (if suspect malignancy - send 50-100mL)"

Examiner: The fluid comes back: PMN 380 cells/mm³, ascitic albumin 10 g/L, serum albumin 24 g/L. What's your diagnosis and management?

Candidate:

"Diagnosis: Spontaneous bacterial peritonitis (SBP)"

"Immediate management:

1. Antibiotics: Ceftriaxone 2g IV once daily (eTG Australia, AASLD 2021)
   • Covers E. coli, Klebsiella (most common SBP organisms)
   • Duration: Minimum 5 days
2. IV Albumin (SORT trial, PMID: 10421978):
   • Day 1: 1.5 g/kg IV within 6 hours
   • Day 3: 1.0 g/kg IV
   • Reduces mortality from 29% to 10%
   • Indicated if Cr >88 μmol/L, BUN >30, or bili >68 μmol/L (consider for all)
3. Repeat tap at 48 hours: Confirm PMN decreasing (>50% reduction)
4. Secondary prophylaxis: Norfloxacin 400mg PO daily after completing treatment (70% recurrence risk without prophylaxis)"

"SAAG calculation: 24 - 10 = 14 g/L (≥11 = portal hypertension, consistent with cirrhosis)"

Examiner: Excellent. Pass.

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Viva Scenario 2: Complications and PPCD

Examiner: You've just drained 9 litres of ascites over 30 minutes. Three hours later, the patient's BP is 82/48 mmHg, HR 118 bpm, and urine output has dropped to 15 mL in the last hour. What has happened?

Candidate:

"This patient has developed post-paracentesis circulatory dysfunction (PPCD)."

Examiner: Explain the pathophysiology.

Candidate:

"PPCD is an effective hypovolemia state occurring 6-24 hours after large volume paracentesis >5L:

1. Rapid ascites removal (9L) decreases intra-abdominal pressure
2. Splanchnic vasodilation persists in cirrhosis (due to nitric oxide, prostacyclins)
3. Relative hypovolemia → decreased effective arterial blood volume
4. Compensatory mechanisms:
   • RAAS activation (renin-angiotensin-aldosterone)
   • Sympathetic activation → tachycardia
   • ADH secretion → hyponatremia
5. Renal vasoconstriction → AKI (prerenal initially, risk of HRS if prolonged)
6. Clinical: Hypotension, tachycardia, oliguria, rapid ascites reaccumulation"

"Incidence: 20-30% after LVP >5L without albumin, but under 5% with albumin."

Examiner: How should this have been prevented?

Candidate:

"IV albumin replacement should have been given:

• Dose: 8 grams per litre drained for LVP >5L
• This patient (9L): 9 × 8 = 72 grams total
  • "Using 20% albumin: 72g ÷ 0.20 = 360 mL IV"
• Timing: During or immediately after LVP completion
• Evidence: EASL 2018 Grade 1A recommendation (PMID: 29653741), reduces PPCD from 20-30% to under 5%"

"No albumin needed if less than 5L drained."

Examiner: How do you manage this patient now?

Candidate:

"Immediate:

1. Exclude hemorrhage: USS abdomen (free fluid, hematoma), Hb trend - PPCD is a diagnosis of exclusion
2. Confirm PPCD: Timing (3 hours post-LVP), volume >5L, no prophylactic albumin given

Resuscitation:

1. IV Albumin: 1-1.5 g/kg over 6 hours (e.g., 70kg patient = 105g = 525mL of 20% albumin)
2. Vasopressors: Noradrenaline if MAP less than 65 mmHg despite albumin (target MAP ≥65)
3. Monitor: Arterial line, UO (target >0.5 mL/kg/hr), lactate

Adjunctive:

1. Withhold diuretics (risk of worsening AKI)
2. Avoid nephrotoxins (NSAIDs, ACE-I, aminoglycosides)
3. Monitor renal function closely (Cr, UO) - risk of type 1 HRS

Future prevention: Always give albumin for LVP >5L."

Examiner: Good. What other complications of paracentesis are you aware of?

Candidate:

"Hemorrhage (under 1%):

• Abdominal wall hematoma (inferior epigastric vessels) - managed with compression, rarely needs IR embolization
• Intraperitoneal hemorrhage (mesenteric vessels, organ capsule) - may need IR embolization or surgery
• Prevention: USS guidance (reduces bleeding 50-70%), Doppler to avoid IEV, Z-track

Bowel perforation (under 0.1%):

• Small gauge needle (18-20G): Usually self-sealing, asymptomatic
• Large catheter: Peritonitis, needs surgical exploration
• Prevention: USS to identify bowel-free pocket, avoid midline in post-surgical patients

Persistent leak (5-10%):

• Causes: Large catheter, obesity, poor Z-track
• Management: Pressure dressing, purse-string suture, skin glue, diuretics

Infection (under 1%):

• Procedural SBP (rare with aseptic technique)
• Abdominal wall cellulitis

PPCD: As discussed above

Other rare:

• Hepatic/splenic laceration (use USS in organomegaly)
• Bladder perforation (empty bladder first)
• Pneumoperitoneum (benign if asymptomatic)"

Examiner: Pass.

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Indigenous Health Considerations

Aboriginal and Torres Strait Islander Populations

Epidemiology:

• 2-3× higher cirrhosis rates due to alcohol use disorder, chronic HBV, NAFLD
• Later presentation with ascites (barriers to healthcare access)
• Higher ICU admission rates for decompensated cirrhosis

Clinical Considerations:

• Alcohol-related liver disease most common cause (60-70%)
• Chronic HBV (5-10× higher prevalence) - consider HBV serology
• NAFLD driven by diabetes (3-4× higher rates)
• Malnutrition common - low ascitic protein increases SBP risk

Cultural Safety:

• Involve Aboriginal Health Workers (AHW) or Aboriginal Liaison Officers (ALO) in consent process
• Family/community involvement in decision-making (collectivist culture)
• Interpreter services if English not first language
• Explain procedure using visual aids, plain language (health literacy considerations)
• Alcohol history: Non-judgmental approach, screen for withdrawal risk

Procedural Modifications:

• Higher vigilance for SBP: Lower threshold for diagnostic tap (may present atypically)
• Nutritional assessment: Low protein increases infection risk
• HBV screening: Check HBsAg, anti-HBc (chronic HBV may need antiviral therapy)

Māori Health Considerations (New Zealand)

Cultural Principles:

• Whānau (family) involvement: Include extended family in consent
• Kaumātua (Elders): Seek guidance for decision-making
• Tikanga (cultural protocols): Respect for body, karakia (prayer) before procedure if requested
• Manaakitanga (hospitality/respect): Ensure dignity, modesty preserved

Health Disparities:

• 1.5-2× higher cirrhosis rates (alcohol, HCV)
• Later presentation to hospital
• Lower transplant rates despite higher need

Practical Approach:

• Māori Health Worker involvement in consent and procedure
• Family presence during procedure if patient wishes
• Explain in plain language, use te reo Māori terms if appropriate
• Respect for body: Handle ascitic fluid with care, explain disposal

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Remote and Rural Considerations

RFDS (Royal Flying Doctor Service) Retrieval

Pre-Retrieval:

• Diagnostic tap: Perform at referring hospital if SBP suspected (do not delay for retrieval)
• Send samples: Cell count, culture (blood culture bottles), albumin
• Start antibiotics: Ceftriaxone 2g IV if PMN ≥250 (do not wait for retrieval)
• Stabilize: Fluid resuscitation, vasopressors if shocked

Aeromedical Considerations:

• Tense ascites: Drain therapeutically pre-flight (respiratory compromise at altitude)
• Avoid large volume: Drain 2-3L only (risk of PPCD during flight) - complete drainage at receiving hospital
• Albumin: Give if draining >5L pre-flight (8g/L)
• Cabin pressure: Equivalent to 6000-8000 feet altitude → worsens hypoxia in respiratory compromise

Limited Resources (Remote Hospitals)

Equipment Availability:

• USS: May not be available 24/7 → use anatomical landmarks (LLQ 2cm medial to ASIS)
• Blood culture bottles: Keep in stock (BACTEC bottles stored at room temperature)
• Albumin: May have limited stock → prioritize for SBP (SORT trial), consider synthetic colloids for LVP PPCD if no albumin

Diagnostic Limitations:

• Cell count: Manual count if automated analyzer unavailable (hemocytometer)
• Culture: Bedside inoculation into blood culture bottles, send to regional lab
• SAAG: Requires serum + ascitic albumin (send to regional lab if no analyzer)

Transfer Indications:

• Refractory shock despite antibiotics + albumin (SBP)
• Suspected secondary peritonitis (surgical abdomen)
• Refractory ascites requiring repeated LVP (consider TIPSS at tertiary center)
• Hepatorenal syndrome (may need RRT, transplant evaluation)

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Special Populations

Pregnancy

Indications: Rare (ascites uncommon in pregnancy)

• HELLP syndrome with ascites
• Budd-Chiari syndrome
• Cirrhosis (preconception disease)

Modifications:

• Mandatory USS guidance (avoid gravid uterus)
• Left lateral decubitus position (avoid IVC compression)
• Obstetric involvement: Fetal monitoring during/after procedure
• Smaller volumes: Avoid >5L to minimize hemodynamic shifts

Obesity

Technical Challenges:

• Thicker abdominal wall: May need longer needle (10-15cm spinal needle)
• USS essential: Difficult to palpate landmarks
• Higher leak risk: Thicker subcutaneous tissue → purse-string suture recommended

Considerations:

• NAFLD cirrhosis common cause of ascites in obese patients
• Hepatic hydrothorax: Right pleural effusion in 5-10% (USS chest pre-procedure)

End-Stage Renal Disease (ESRD)

Causes of Ascites:

• Peritoneal dialysis (PD) - drain PD fluid first before diagnostic tap
• Cirrhosis + ESRD (10-15% of dialysis patients)
• Nephrogenic ascites (rare)

Modifications:

• Avoid right-sided taps if peritoneal dialysis catheter present (left-sided exit site)
• Sterile technique critical (PD patients at high infection risk)
• Low SAAG: Nephrotic syndrome (even if portal hypertension also present)

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Equipment Troubleshooting

Dry Tap (No Fluid Return)

Causes:

• Needle not in peritoneal cavity (too shallow)
• Loculated ascites (septated)
• Needle blocked by omentum
• Patient positioning (fluid not at puncture site)

Solutions:

• USS real-time guidance: Visualize needle tip entering fluid pocket
• Reposition patient: Lateral decubitus (procedure-side up) to pool fluid
• Redirect needle: Withdraw to subcutaneous tissue, angle differently
• Catheter insertion: Pigtail catheter may navigate around omentum better than rigid needle

Blood-Stained Aspirate

Causes:

• Traumatic tap: Vessel puncture during insertion (clears with continued aspiration)
• True hemorrhagic ascites: Malignancy, TB (remains bloody)

Differentiation:

• Traumatic: Blood clears as aspiration continues, clots form in syringe
• True: Remains uniformly blood-stained, does not clot (defibrinated)

Management:

• If traumatic: Continue aspiration (fluid will clear), send for analysis
• If arterial puncture (pulsatile, bright red): Leave needle in place, apply pressure after removal, vascular surgery consult if expanding hematoma

Persistent Leak

Prevention:

• Z-track technique (creates tortuous path)
• Purse-string suture around catheter before removal (for large catheters)
• Pressure dressing for 24 hours

Management:

• Skin glue (dermabond) or single suture to close tract
• Increase diuretics (reduce ascites production)
• Albumin infusion (if contraindicated to increase diuretics)
• Ostomy bag if persistent (rare, may need IR embolization of tract)