Ascites for USMLE Step 2. Pathophysiology, clinical findings, management, signs and symptoms, and treatment.
PATHOPHYSIOLOGY
It is not completely known, however, they have a state of high Sodium and Water. The first theory is the underfilling theory where the circulatory system is underfilled. Portal hypertension causes increase pressure in portal vein and accumulation of fluid in splanchnic veins, and so therefore the is a decrease in circulatory blood volume. Activation of Renin Angiotensin Aldosterone system causing Sodium/Water retention
OVERFLOW THEORY
There if no volume depletion, but the renal retains water and Sodium because it thinks there is volume depletion
Vasodilation theory - portal hypertension leads to vasodilation due to release of mediators, such as VIP, Sub P, PAF, PG, NO Therefore there is low circulatory blood volume and activation of RAA system and Sodium and Water Retention.
There is Sodium and Water retention, but overall there is dilutional hyponatremia.
ETIOLOGY
Non peritoneal Portal Hypertension - cirrhosis, alcoholic hepatitis, hepatic failure
Hepatic Congestion Budd-chiari, Congestive Heart Failure, Constrictive Pericarditis, Tricuspid Insufficiency
Chylous, Pancreatic, Bile, Nephrogenic, Ovarian Disease
Hypoalbuminemia - Nephrotic syndrome, Protein losing enteropathy and malnutrition
Peritoneal causes
Bacterial, Fungal and TB peritonitis, HIV peritonitis
Malignancies,
CLINICAL
Abdominal girth, Shortness of breath, Early Satiety, Spontaneous bacterial peritonitis (Fever, Tenderness, Altered Mental Status)
Underlying Symptoms
Liver disease jaundice, gynecomastia, muscle wasting
Cirrhosis spider angiomas, palmar erythema
Heart Failure JVP, edema, Pulmonary congestion
PHYSICAL EXAMINATION
Flank Dullness, Shifting Dullness, Fluid Wave
INVESTIGATIONS
Imaging to confirm
Ultrasound 5 to10mL of fluid in morrison pouch
CT Scan will show fluid moving the liver
Paracentesis
Indication is new onset ascites, fever pain tenderness WBC, Mental Status Change, drop in Blood pressure or GI Bleed
Color
Chylous Lymphomas, Cirrhosis Lymphatic rupture, TAG greather 20mg/dL Protein
Bloody - greather than50K cells/mm3, Traumatic paracentesis, cirrhosis, Hepatocellular Carcinoma
Cloudy/Turbid - SBP (98%)
Brown - Jaundice, Ruptured Gallbladder, Peforated duodenal ulcer
Clear - Cirrhosis, Uncomplicated
Serum Ascites Albumin Gradient (SAAG) take the serum albumin and subtract from ascetic albumin. If greater than 1.1 than it is portal hypertension. And if less than 1.1 than it rules out portal hypertension
Cell Count - High WBC and Neutrophils suggest Spontaneous Bacterial Peritonitis
Culture, Glucose, LDH, Gram stain, Amylase, Biopsy, ADA, Total Protein
TREATMENT
Initial management starts with therapeutic paracentesis. Small volume is less than 5 liters and large volume will require replacement with 5 g albumin.
Long Term - no alcohol, Decrease Sodium and water intake, Diuretic such as furosemide and Spironolactone
Surgery - Tranjugular intrahepatic portosystemic shunt (TIPS)