What is the approach to abdominal examination in a patient with chronic liver disease (CLD), portal hypertension, and ascites?

Abdominal Examination in CLD with Portal Hypertension and Ascites

In patients with chronic liver disease, portal hypertension, and ascites, the abdominal examination should focus on detecting shifting dullness (which has 83% sensitivity for ascites), assessing for splenomegaly, identifying stigmata of portal hypertension, and distinguishing cardiac from hepatic causes through jugular venous distension assessment. 1, 2

Systematic Approach to Physical Examination

Percussion for Ascites Detection

• Percuss the flanks with the patient supine to identify flank dullness, which indicates fluid accumulation when the tympany-dullness interface is higher than normally found on the lateral abdomen 1, 2
• Test for shifting dullness by having the patient roll to one side and re-percussing—this maneuver has 83% sensitivity and 56% specificity for detecting ascites 1, 2
• Approximately 1,500 mL of fluid must be present before flank dullness becomes detectable; if no flank dullness is present, the patient has less than 10% chance of having ascites 1, 2
• Avoid relying on fluid wave or puddle sign, as these techniques are cumbersome and perform less well compared to shifting dullness 1

Assessment of Portal Hypertension Signs

• Palpate for splenomegaly, which signifies portal hypertension and is an important finding on ultrasound evaluation 1, 2
• Inspect for visible collateral vessels on the abdominal wall, which indicate portosystemic shunting 3
• Examine for hepatomegaly or a small, nodular liver, depending on the stage of cirrhosis 1

Distinguishing Cardiac from Hepatic Ascites

• Assess jugular venous distension (JVD), which is present in ascites due to alcoholic cardiomyopathy but absent in cirrhotic ascites 1, 2
• This distinction is critical as both conditions can present similarly in alcoholic patients 1
• Consider measuring brain natriuretic peptide (BNP) if cardiac ascites is suspected—median pro-BNP is 6,100 pg/mL in cardiac ascites versus only 166 pg/mL in cirrhotic ascites 1, 2

Essential Diagnostic Paracentesis

Indications and Technique

• Perform diagnostic paracentesis in all patients with new-onset Grade 2 or 3 ascites and in all hospitalized patients with worsening ascites or complications 1, 2
• Conduct surveillance paracentesis on admission because spontaneous bacterial peritonitis is present in approximately 15% of cirrhotic patients at hospital admission 1, 2
• Select the paracentesis site approximately 15 cm lateral to the umbilicus in the left or right lower quadrant, avoiding the inferior and superior epigastric arteries and any enlarged liver or spleen 1, 2
• Withdraw 10-20 mL of fluid for diagnostic purposes using a blue or green needle 1, 2

Safety Considerations

• Coagulopathy is NOT a contraindication to paracentesis—complications occur in only 1% of patients (mainly abdominal wall hematomas), despite 71% having abnormal prothrombin time 1, 2
• Do not routinely give fresh frozen plasma or platelets before paracentesis, as this practice is not data-supported and routine coagulation tests do not reflect bleeding risk in cirrhosis 1
• Serious complications (hemoperitoneum, bowel perforation) are rare (<1/1000 procedures) 1

Critical Ascitic Fluid Analysis

Mandatory Initial Tests

• Calculate serum-ascites albumin gradient (SAAG) by measuring both serum and ascitic fluid albumin simultaneously—SAAG ≥1.1 g/dL indicates portal hypertension with 97% accuracy 1, 2, 4
• Obtain ascitic fluid neutrophil count to screen for spontaneous bacterial peritonitis (SBP), diagnosed when neutrophils >250 cells/mm³ 1, 2
• Inoculate 10 mL of ascitic fluid into two blood culture bottles at bedside to maximize bacterial detection 1, 2
• Measure total ascitic fluid protein concentration to assess SBP risk—patients with protein <15 g/L have increased risk 1

Appearance-Based Considerations

• Note if fluid appears white and milky, which suggests chylous ascites and requires triglyceride measurement >200 mg/dL for confirmation 5
• Recognize that bloody ascites (RBC count ≥10,000/mm³) should prompt evaluation for hepatocellular carcinoma, peritoneal carcinomatosis, or tuberculous peritonitis 6
• Do not rely solely on appearance for diagnosis—turbid fluid can result from infection or tumor cells, not just chyle 5

Complementary Investigations

Blood Tests

• Obtain urea and electrolytes, liver function tests, prothrombin time, and full blood count on admission 1
• Measure BNP or pro-BNP if cardiac ascites cannot be excluded clinically 1, 2

Imaging

• Perform abdominal ultrasound to evaluate liver appearance, screen for hepatocellular carcinoma, assess portal vein patency, detect hepatic vein thrombosis, and confirm splenomegaly 1, 2
• Use ultrasound in obese patients when physical examination is inconclusive, as it can detect ascites when volume exceeds 100 mL 2

Common Pitfalls to Avoid

• Do not assume alcoholic patients have alcoholic liver disease—other causes must be excluded through proper testing 1
• Do not skip paracentesis due to coagulopathy concerns—the bleeding risk is minimal and does not justify withholding this essential diagnostic procedure 1
• Do not forget to correct neutrophil count in hemorrhagic ascites by subtracting 1 neutrophil for every 250 RBCs to avoid false-positive SBP diagnosis 6
• Do not confuse slowly enlarging abdomen over months to years with ascites—this pattern suggests obesity rather than fluid accumulation, which typically develops over weeks 1, 2