A paracentesis is the insertion of a needle or catheter into the peritoneal cavity to remove ascitic fluid
Classification
| Classification | Description |
|---|---|
| Diagnostic paracentesis | Performed to determine the cause of ascites and exclude spontaneous bacterial peritonitis (SBP) |
| Therapeutic paracentesis | Performed to relieve tense or refractory ascites |
- Indications
- Diagnostic paracentesis
- New-onset ascites
- Hospitalized patient with ascites
- Suspected SBP – abdominal pain, fever, hypotension, sepsis, GI bleeding, encephalopathy, renal deterioration, and hepatic deterioration
- Therapeutic paracentesis
- Tense ascites
- Refractory ascites despite diuretics
- Significant abdominal discomfort
- Respiratory distress
- Large volume paracentesis (> 5 litres)
- To reduce intra-abdominal pressure in abdominal compartment syndrome
- Diagnostic paracentesis
- Contraindications
- Absolute
- Acute abdomen (requires surgery)
- Disseminated intravascular coagulopathy (DIC)
- Relative (ultrasound guidance is preferred)
- Pregnancy
- Organomegaly
- Intestinal obstruction or ileus
- Distended bladder
- Surgical scars
- Severe thrombocytopaenia (PLT < 20,000) or marked coagulopathy (abnormal INR/PT is not an indication for routine FFP before paracentesis)
- Absolute
- Procedure
- Obtain informed consent
- Positioning
- Supine with a wedge on one side if needed
- Empty bladder
- Site
- Right or left lower quadrant lateral to the rectus sheath and superior to the ASIS
- Midline ~ 2 cm below the umbilicus
- Lateral ~ 5 cm superior and medial to the ASIS
- Avoid scars and prominent abdominal veins
- Ultrasound guidance is preferred to identify a safe fluid pocket
- Sterile preparation with chlorhexidin or povidone-iodine and sterile draping
- Infiltrate up to the peritoneum with 1% plain lidocaine
- Insert a 16G needle or catheter using Z-track technique to reduce leakage
- Aspirate until free-flowing ascitic fluid is obtained
- Advance the catheter and withdraw the needle
- Collect diagnostic samples
- Connect the catheter to the drainage system in case of therapeutic drainage. Cotton swabs or gauze swabs can be used to support the catheter
- Remove the catheter and apply pressure with gauze swabs
- Indications for albumin replacement
- Albumin is replaced in large-volume paracentesis (> 5 litres) or any paracentesis with creatinine > 1.5 g/dL (132 umol/L)
- 25% albumin 6 – 8 g per liter of ascitic fluid removed
- This prevents post-paracentesis circulatory dysfunction and hypotension
- Spontaneous bacterial paracentesis
- 25% albumin 1.5 g/kg on day 1
- This reduces acute kidney injury and hepatorenal syndrome (HRS)
- Albumin is replaced in large-volume paracentesis (> 5 litres) or any paracentesis with creatinine > 1.5 g/dL (132 umol/L)
- Ascitic fluid analysis
- Appearance
- Cell count + differential
- Ascitic PMN ≥ 250 cells/mm3 is diagnostic of SBP
- Albumin
- SAAG ≥ 1.1 g/dL portal hypertension is likely
- SAAG ≤ 1.1 g/dL portal hypertension is unlikely
- Total protein
- For SAAG ≥ 1.1, ascitic protein > 2.5 g/dL is more suggestive of cardiac ascites
- For SAAG ≥ 1.1, ascitic protein < 2.5 g/dL is more suggestive of cirrhotic ascites
- Gram stain
- Culture (preferably inoculated into blood culture bottles to increase yield)
- TB testing (AFB, GeneXpert, culture or ADA)