Write a Review
x
Feedback Gastrology

Ascites

  • Accumulation of free fluid in the peritoneal cavity
  • Large volume (>1L) causes symptoms e.g. – abdominal distension, fullness in flanks, shifting dullness, fluid thrill
    • Other symptoms – eversion of umbilicus, hernia, abdominal striae, scrotal oedema
    • Dilated superficial abdominal veins if ascites is due to portal hypertension (PHTN)
  • Causes – see table

Pathophysiology

  • MCC is malignant disease, cirrhosis, heart failure
  • Splanchnic vasodilation – MCC of ascites in cirrhosis
    • Mediated by NO released when PHTN causes shunting of blood into systemic circ
    • Systemic arterial pressure falls due to splanchnic VD as cirrhosis advances
    • This leads to activation of RAS with 2o aldosteronism, increases SNS activity, altered kallikrein-kinin system
    • This system normalises arterial pressure but produces salt and water retention
  • The combo of splanchnic arterial vasodilation and Pulmonary HTN alters intestinal capillary permeability – promotes accumulation of fluid in the peritoneum

Investigations

  • USS – can detect small volumes in obese pts
  • Paracentesis  – for analysis (see box)
  • Pleural effusions on right ride – hepatic hydrothorax (CXR)
  • Total protein content (TPC)
    • TPC <25g/L – transudate
    • TPC >25g/L – exudate
    • Serum-ascites albumin gradient (SAAG) – to determine cause of ascites
    • SAAG = serum [ALBUMIN] – ascite fluid [ALBUMIN]
      • SAAG >11g/L – indicates ascites from Portal HTN
      • SAAG <11g/L – indicates ascites from non-liver disease (neoplaisa, TB, Nephrotic syndrome )
  • Amylase >1000U/L – indicates pancreatic ascites
  • Low glucose – malignancy/TB
  • PMNL > 250X106 – infection (indicates spontaneous bacterial peritonitis)

Management

  • Transudate ascites – sodium and water restriction; diuretics (no more than 1L/d); paracentesis
  • Exudative ascites due to malignancy – paracentesis; fluid management not required
  • Patient should be weighted regularly
  • Sodium and water restriction
    • 100mmol/d restriction
    • Avoid sodium promoting drugs (see box)
    • Restriction of water to 1-1.5L/d if plasma sodium <125mmol/l
  • Diuretics
    • Spironolactone (100-400mg/d) – powerful aldosterone antag
      • SE – gynecomastia, hyperkalemia (must monitor)
    • Furosemide – second line
  • Paracentesis – first line tx for refractory ascites
  • TIPS – relieves resistant ascites but doesn’t prolong life

Complications

  • Renal failure
  • Hepatorenal syndrome (HRS) – occurs in 10% of pts with advanced cirrhosis complicated by ascites. Mediated by renal vasoconstriction due to underfilling of arterial circulation
    • Type 1 HRS – progressive oliguria, rapid rise of serum creatinine, poor prognosis
      • Treatment – albumin infusions combined with terlipressin
      • Consider pts for liver transplantation
    • Type 2 HRS – in patients with refractory ascites; moderate and stable increase in serum creatinine
      • Better prognosis
  • Spontaneous bacterial peritonitis
    • Abdominal pain, rebound tenderness, absent bowel sounds, fever – in pt with cirrhosis and ascites
    • Can also present with hepatic encephalopathy
    • Paracentesis – cloudy fluid, neutrophil >250×106
    • MC organism is E.coli
    • Treatment – broad spec antibiotics (cefotaxime or piperacillin/tazobactam)
Feedback