Management of Paracentesis in Patients with Ascites
Pre-Procedure Steps
Obtain informed consent from the patient before performing therapeutic or diagnostic paracentesis, as this is a strong recommendation across all major guidelines. 1
Patient Assessment and Laboratory Testing
Do NOT routinely measure prothrombin time or platelet count before paracentesis, and do NOT transfuse blood products prophylactically. 1, 2 Paracentesis can be safely performed even with significant coagulopathy (INR as high as 8.7 and platelet counts as low as 19,000 cells/mm³), with bleeding complications occurring in less than 1 in 1,000 procedures. 2
The only absolute contraindications are clinically evident hyperfibrinolysis (manifested by three-dimensional ecchymosis or hematoma formation) and disseminated intravascular coagulation. 2
Site Selection and Ultrasound Guidance
Select the left lower quadrant as the preferred site: 2 finger breadths (3 cm) cephalad and 2 finger breadths medial to the anterior superior iliac spine. 2 This location has thinner abdominal wall and greater depth of ascites compared to midline approaches. 2
Consider ultrasound guidance when available to reduce the risk of adverse events, particularly in patients with obesity, pregnancy, severe intestinal distension, or history of extensive abdominal surgery. 1, 3 Ultrasound should be used to identify the needle insertion site based on fluid collection size, abdominal wall thickness, and proximity to organs. 3
Use color flow Doppler to identify and avoid abdominal wall blood vessels along the anticipated needle trajectory. 3 The inferior and superior epigastric arteries run just lateral to the umbilicus and must be avoided. 1, 2
Ensure the puncture site is at least 8 cm from the midline and 5 cm above the symphysis pubis to minimize vascular injury risk. 2
During the Procedure
Fluid Collection for Diagnostic Testing
For diagnostic paracentesis, withdraw 10-20 mL of ascitic fluid using a syringe with a blue or green needle. 1
Inoculate ascitic fluid into two blood culture bottles at the bedside immediately to maximize detection of spontaneous bacterial peritonitis (SBP). 1
Send fluid for: neutrophil count (in EDTA tube), serum-ascites albumin gradient (SAAG), total protein, and culture. 1
Request ascitic fluid amylase when there is clinical suspicion of pancreatic disease. 1
Request cytology only when there is clinical suspicion of underlying malignancy. 1
Large Volume Paracentesis Technique
For large volume paracentesis (>5 L), perform the drainage in a single session rather than multiple smaller taps. 1
Monitor the patient for complications during drainage, including hypotension, tachycardia, and signs of circulatory dysfunction. 4
If acute shivering occurs during drainage, immediately stop or slow the drainage rate, apply external warming with heated blankets or forced-air warming devices, and administer intravenous meperidine 12.5-50 mg as the most effective pharmacological intervention. 5
Post-Procedure Management
Albumin Replacement
Albumin (20% or 25% solution) should be infused after paracentesis of >5 L is completed at a dose of 8 g albumin per liter of ascites removed. 1 This is a high-quality, strong recommendation that prevents post-paracentesis circulatory dysfunction, renal impairment, and severe hyponatremia. 6
For paracentesis <5 L, albumin can be considered in patients with acute-on-chronic liver failure (ACLF) or high risk of post-paracentesis acute kidney injury. 1
Synthetic plasma expanders (150-200 mL of gelofusine or haemaccel) may be used for uncomplicated paracentesis <5 L, though albumin remains superior. 1, 6
The use of albumin is critical because paracentesis without plasma volume expansion consistently causes deterioration of effective circulating blood volume and may induce renal impairment and severe hyponatremia. 7, 6
Immediate Post-Procedure Assessment
Screen all patients for spontaneous bacterial peritonitis (SBP) by checking the ascitic fluid neutrophil count. 1 An ascitic neutrophil count ≥250 cells/mm³ is diagnostic of SBP. 1
If the neutrophil count is ≥250 cells/mm³, immediately start empiric antibiotic therapy with a third-generation cephalosporin (e.g., intravenous cefotaxime 2 g every 8 hours) before culture results are available. 1
For patients with SBP and elevated or rising serum creatinine, administer albumin 1.5 g/kg within 6 hours of diagnosis, followed by 1 g/kg on day 3 to prevent hepatorenal syndrome. 1
Monitoring for Complications
Monitor for signs of post-paracentesis circulatory dysfunction: hypotension, tachycardia, rising creatinine, and hyponatremia. 6
Abdominal hematomas occur in up to 1% of patients but are rarely serious or life-threatening. 1 More serious complications such as hemoperitoneum or bowel perforation are rare (<1/1000 procedures). 1
Follow-up paracentesis is not routinely needed in patients with typical SBP who respond dramatically to antibiotics. 1 However, repeat paracentesis should be performed if the setting, symptoms, analysis, organism(s), or response are atypical, as this may indicate secondary peritonitis requiring surgical intervention. 1
Ongoing Management After Paracentesis
Diuretic Therapy
After large volume paracentesis, patients require diuretic therapy to prevent reaccumulation of ascites. 1, 7
Start with spironolactone monotherapy at 100 mg daily, increasing to 400 mg daily as needed. 1
If spironolactone alone is inadequate, add furosemide starting at 40 mg daily, increasing to 160 mg daily. 1
Monitor serum electrolytes closely, particularly during the first weeks of treatment. 1
Management of Hyponatremia
For serum sodium 126-135 mmol/L with normal creatinine: continue diuretics but monitor electrolytes closely; do not restrict water. 1
For serum sodium 121-125 mmol/L with normal creatinine: consider stopping diuretics or adopting a more cautious approach. 1
For serum sodium 121-125 mmol/L with elevated creatinine (>150 mmol/L or >120 mmol/L and rising): stop diuretics and give volume expansion. 1
For serum sodium <120 mmol/L: stop diuretics and perform volume expansion with colloid (haemaccel, gelofusine, or voluven) or saline, but avoid increasing serum sodium by >12 mmol/L per 24 hours. 1
Long-Term Considerations
Consider liver transplantation evaluation in all patients with cirrhotic ascites, as the development of ascites is an important landmark indicating poor prognosis. 1 All patients with SBP should be considered for referral for liver transplantation. 1
For patients with refractory ascites requiring frequent therapeutic paracentesis, consider transjugular intrahepatic portosystemic shunt (TIPSS) after appropriate risk-benefit assessment. 1
Critical Pitfalls to Avoid
Never assume coagulopathy is a contraindication to paracentesis or routinely transfuse blood products prophylactically. 1, 2 This wastes resources and exposes patients to unnecessary transfusion risks without improving safety.
Never perform large volume paracentesis without albumin replacement for volumes >5 L. 1, 6 This consistently causes circulatory dysfunction and increases mortality risk.
Never delay antibiotic therapy while waiting for culture results if the neutrophil count is ≥250 cells/mm³. 1 Empiric treatment must be started immediately.
Do not assume ascites in an alcoholic patient is due to alcoholic liver disease; always perform diagnostic paracentesis to exclude other causes including malignancy and infection. 1