ASCITES Flashcards
What is ascites?
Ascites = fluid within the peritoneal cavity, a common complication of cirrhosis.
What is the 3 underlying pathogeneses of ascites?
- Sodium & water retention: due to peripheral arterial vasodilation (2’ to nitric oxide, ANP & prostaglandins) causing a reduction in the effective blood volume. Low blood volume activates sympathetic nervous system and RAAS, promoting salt & water retention.
- Portal hypertension: local hydrostatic pressure leading to increased hepatic lymph production and transudation of fluid into peritoneal cavity.
- Low serum albumin: due to poor liver function, further reducing plasma oncotic pressure
What are the clinical features of ascites & tense ascites?
Abdominal swelling
Pain/discomfort
Severe pain (suspicious of SBP)
Peripheral oedema
Respiratory distress & difficulty eating in tense ascites
What are the precipitating factors of ascites?
Excess alcohol consumption
Infection/sepsis
HCC/splanchnic vein thrombosis
How do you confirm the diagnosis of ascites?
Shifting dullness confirms the presence of fluid.
When may you find a right-sided pleural effusion (rare) as a result of ascites?
Congenital diaphragmatic defect allows passage for ascites
Which investigations are carried out for ascites?
Diagnostic aspiration, aka ascitic tap (10-20ml) obtained for:
Cell count - high neutrophil count (>250cells) indicative of spontaneous bacterial peritonitis
Gram stain & culture
Protein measurement -
high serum-ascites albumin = portal hypertension;
low serum-ascites albumin = non-liver disease related abnormalities of peritoneum
Cytology - malignant cells
Amylase - to exclude pancreatitis ascites
What is the aim of managing ascites?
Reduce sodium intake and to increase renal sodium excretion => producing a net reabsorption of fluid from ascites into the circulating volume.
How do you manage ascites?
- Check electrolytes, creatinine (U&E) and eGFR rate on alternate days. Weigh the patient & measure urinary output daily.
- Dietary sodium restriction (40mmol in 24hrs)
- Fluid restriction (<1.5L/day)
- Drugs - Limit high in sodium & sodium retaining drugs ie antacids, antibiotics, NSAIDs and corticosteroids
- Diuretics - start spironolactone (aldosterone antagonist 100mg - works by correcting RAAS) => chronic admin results in gynaecomastia; Eplerenone does not produce gyaecomastia.
If response is poor, add furosemide
Aim of diuretic therapy is to produce a net loss of 700ml fluid in 24hours.
In which conditions would you see a high serum-ascites albumin gradient?
- Portal hypertension e.g. cirrhosis
- Hepatic outflow obstruction
- Budd-Chiari syndrome
- Hepatic veno-occlusive disease
- Tricuspid regurgitation
- Constrictive pericarditis
- Right-sided heart failure
In which conditions would you see a low serum-ascites albumin gradient?
- Peritoneal carcinomatosis
- Peritoneal tuberculosis
- Pancreatitis
- Nephrotic syndrome
How do you manage symptomatic tense ascites?
How much fluid can be removed?
Paracentesis for tense ascites or when diuretic therapy is insufficient.
Up to 20L can be removed over 4-6 hours, with albumin infusion.
What are the complications of paracentesis?
Hypovolaemia and renal dysfunction (when more than 5L is removed and in patients with worse liver function)
In patients with normal renal function and without hyponatraemia, hypovolaemia is overcome by infusing albumin.
How do you treat resistant ascites?
Using a TIPS (transjugular intrahepatic portosystemic shunt)
What are the causes of straw coloured ascitic fluid?
Malignancy (most common cause)
Cirrhosis
Infective i.e. Tuberculosis, after intra-abdominal perforation, spontaneous bacterial peritonitis in cirrhosis
Hepatic vein obstruction ie Budd-Chiari syndrome
Chronic pancreatitis
Congestive cardiac failure
Constructive pericarditis
