Ascites Flashcards
What are the causes of abdominal distention?
- Fat
- Fluid
- Flatus
- Faeces
- Fetus
- Filthy tumour (organ enlargement, malignancy)
What is ascites?
Pathologically accumulation of fluid in peritoneal cavity
How much fluid must be present before there is flank dullness and fluid thrill?
500mL for shifting dullness
1.5L for fluid thrill
What are the causes of ascites?
* denotes commonest cause
(Transudative) SAAG > 1.1 g/dL (> 11g/L)
-> Formed as a result of portal hypertension
- Liver cirrhosis*
- Budd chiari
- Congestive heart failure*
- Constrictive pericarditis
- Malabsorption and protein losing enteropathy
- Meig’s syndrome
- Hypothyroidism
- Lymphadenopathy
- Nephrotic or nephritic syndrome, ESRF
(Exudative) SAAG < 1.1 g/dL (< 11 g/L)
- Intra-abdominal malignancy*
- Tuberculosis
- Nephrotic syndrome
- Pancreatitis
- SLE
What is the pathophysiology of ascites in liver cirrhosis?
- Splanchnic arterial vasodilation
- Increased resistance to portal flow - > portal hypertension -> local production of vasodilators - Arterial underfilling
- Early stage: minimal effect on effective arterial volume, compensated by increase in plasma volume and cardiac output
- Late stage: effective arterial pressure falls, activation of vasoconstrictors and atrial natriuretic factors (RAAS)
- Sodium and fluid retention and expansion of plasma volume
- Impaired free water excretion -> dilutional hyponatraemia
- Renal vasoconstriction with hepatorenal syndrome - Increase in splanchnic capillary pressure with lymph formation exceeding return
How would you investigate the cause of ascites?
- Paracentesis - 2FB cephalad and medial to ASIS in left lower quadrant
- Cell count, albumin, total protein concentration
- Culture and sensitivity, AFB
- Cytology
- SAAG: serum albumin - ascitic albumin - US HBS or CT TAP
- Mass
- Splenomegaly
- Portal hypertension
- Thrombosis - TTE and ECG
- CXR
- FBC, LFT and bilirubin, RP, TFT, coag
How would you manage a patient with ascites from liver cirrhosis?
- Treat underlying cause
- Avoid alcohol and hepatotoxic medication
- Salt restriction < 2g/day
- Fluid restriction < 1L/day
- Diuretics - furosemide, spironolactone
- High dose spironolactone up to 400mg per day
- High dose furosemide up to 160mg per day - Paracentesis with albumin replacement
- Replace IV albumin 20% 100mL for every 2L removed (equivalent to 8g per litre) - TIPSS (transjugular intrahepatic portosystemic shunt)
- Care: high rate of shunt stenosis up to 75% at 1 year - Liver transplant
- 5 year survival: 70-80% (vs without 30-40%)
- MELD scoring
- Consider in refractory ascites, SBP or HRS - Manage other complications of cirrhosis
What is spontaneous bacterial peritonitis (SBP)?
What are the common organisms involved?
Translocation of bacteria from intestinal lumen to peritoneal cavity, LNs then bacteraemia.
Defined as >250 polymorphs per mL of ascitic fluid
Common organisms
1. E. coli or enterobacteriaceae (60%)
2. Klebsiella pneumoniae
3. Streptococcus pneumoniae (15%)
4. Enterococci (10%)
5. Anaerobes (<1%)
What is the ascitic fluid panel findings of SBP?
- Polymorphs > 250, or as high as > 1000 (WBC > 300)
- LDH > upper limit of serum
- Low glucose
- High protein > 1g/L
- CEA > 5
- ALP > 240
- Culture positive
What is the treatment and prevention of SBP?
What is the recurrence rate of SBP?
- 3rd generation cephalosporin - ceftriaxone
- Antibiotics prophylaxis - ciprofloxacin, norfloxacin
- IV albumin to prevent HRS
Recurrence as high as 70% per year
What does development of ascites in patient with liver cirrhosis mean?
(Prognosis of ascites in liver cirrhosis)
Decompensation
Occurs in 50% patients within 10 year of diagnosing compensated cirrhosis
Poor prognosis, only 50% survive beyond 2 years
Poor QoL
Increased risk of infection and renal failure
History taking of ascites
- Abdominal distention
- Onset (acute or gradual), duration
- Quantity - weight gain, distention inches
- Associated features: LL oedema, SOB, exertional, orthopnoea, PND, facial oedema - Precipitating factors
- Sepsis, SBP
- BGIT
- Recent hepatotoxic drugs
- Recent surgery or trauma - Complications of ascites
- Fever, abdominal pain, diarrhoea -> peritonitis
- SOB -> splinting of diaphragm
- Dehydration, intravascular volume depletion -> AKI
- Constitutional symptoms, early satiety -> malignancy - Complications of liver cirrhosis
- Bleeding varices - UBGIT, LBGIT
- Encephalopathy - lethargy, drowsiness, confusion, behavioural changes - Past medical history and cause of PMH
- Cardiovascular
- Hepatic and cause of liver cirrhosis
- Renal
- Malignancy
- Alcoholism, sexual contact, hepatitis status
- PTB contact - Medications and vaccination
- Hepatotoxic drugs
- Vaccination history - up to date
What are the clinical features of SBP?
- Fever
- Abdominal pain
- Encephalopathy
How do you determine the causes of ascites clinically?
- Cirrhosis
- Distended abdominal veins with downward flow of blood
- Signs of chronic liver disease - Cardiac
- Raised JVP - Cancer or tuberculosis
- Cachexia
- Lymphadenopathy - Hypoalbuminaemia
- Anasarca over UL, trunk, UL and even face
What are the examination findings/signs of ascites?
Examination of ascites
1. Abdomen distention
2. Umbilicus everted
3. Abdomen dull to percussion in flanks
4. Shifting dullness
5. Fluid thrill
6. Volume status - dehydrated vs overload (in CHF, constrictive pericarditis)
Specific features
6. Lymphadenopathy - malignancy, PTB, CMV, toxoplasma, HIV, SLE, sarcoidosis
7. Signs of chronic liver disease - cirrhosis
8. Abdominal pain, fever, AMS - SBP
