Causes of high serum-ascites albumin gradient (SAAG or transudate) are:[5]
Cirrhosis – 81% (alcoholic in 65%, viral in 10%, cryptogenic in 6%)&Heart failure – 3%&Hepatic venous occlusion: Budd–Chiari syndrome or veno-occlusive disease&Constrictive pericarditis&Kwashiorkor (childhood protein-energy malnutrition
Causes of low SAAG ("exudate") are:
Cancer (metastasis and primary peritoneal carcinomatosis) – 10%&Infection: Tuberculosis – 2% or spontaneous bacterial peritonitis&Pancreatitis – 1%&Serositis&Nephrotic syndrome[6]&Hereditary angioedema[7
Other rare causes:
Meigs syndrome&Vasculitis&Hypothyroidism&Renal dialysis&Peritoneum mesothelioma&Abdominal tuberculosis&Mastocytosi
Routine complete blood count (CBC), basic metabolic profile, liver enzymes, and coagulation should be performed. Most experts recommend a diagnostic paracentesis be performed if the ascites is new or if the patient with ascites is being admitted to the hospital. The fluid is then reviewed for its gross appearance, protein level, albumin, and cell counts (red and white). Additional tests will be performed if indicated such as microbiological culture, Gram stain and cytopathology.[5]
The serum-ascites albumin gradient (SAAG) is probably a better discriminant than older measures (transudate versus exudate) for the causes of ascites.[8] A high gradient (> 1.1 g/dL) indicates the ascites is due to portal hypertension. A low gradient (< 1.1 g/dL) indicates ascites of non-portal hypertensive as a cause.
Ultrasound investigation is often performed prior to attempts to remove fluid from the abdomen. This may reveal the size and shape of the abdominal organs, and Doppler studies may show the direction of flow in the portal vein, as well as detecting Budd-Chiari syndrome (thrombosis of the hepatic vein) and portal vein thrombosis. Additionally, the sonographer can make an estimation of the amount of ascitic fluid, and difficult-to-drain ascites may be drained under ultrasound guidance. An abdominal CT scan is a more accurate alternate to reveal abdominal organ structure and morphology.[citation needed]
Classification[edit] => Ascites exists in three grades:[9]
Grade 1: mild, only visible on ultrasound and CT&Grade 2: detectable with flank bulging and shifting dullness&Grade 3: directly visible, confirmed with the fluid wave/thrill tes
Mild ascites is hard to notice, but severe ascites leads to abdominal distension. Patients with ascites generally will complain of progressive abdominal heaviness and pressure as well as shortness of breath due to mechanical impingement on the diaphragm.
Ascites is detected on physical examination of the abdomen by visible bulging of the flanks in the reclining patient ("flank bulging"), "shifting dullness" (difference in percussion note in the flanks that shifts when the patient is turned on the side) or in massive ascites with a "fluid thrill" or "fluid wave" (tapping or pushing on one side will generate a wave-like effect through the fluid that can be felt in the opposite side of the abdomen).
Other signs of ascites may be present due to its underlying cause. For instance, in portal hypertension (perhaps due to cirrhosis or fibrosis of the liver) patients may also complain of leg swelling, bruising, gynecomastia, hematemesis, or mental changes due to encephalopathy. Those with ascites due to cancer (peritoneal carcinomatosis) may complain of chronic fatigue or weight loss. Those with ascites due to heart failure may also complain of shortness of breath as well as wheezing and exercise intolerance.