Urgent considerations
See Differentials for more details
Newly diagnosed ascites always requires urgent evaluation with imaging, usually starting with an abdominal ultrasound to confirm or refute the diagnosis and detect evidence of cirrhosis or malignancy. Doppler ultrasound and diagnostic paracentesis are also required. Patients presenting with ascites should be evaluated for the following complications or urgent conditions.
Spontaneous bacterial peritonitis
Spontaneous bacterial peritonitis (an infection of previously sterile ascitic fluid without apparent intra-abdominal source of infection) is a medical emergency. It may be minimally symptomatic or asymptomatic in initial stages. Abdominal pain and fever are the most characteristic symptoms.
Randomised controlled trials comparing antibiotic regimens have described an in-hospital mortality rate of 10% to 28%.[16][17][18][19]
Diagnostic paracentesis is the most important test to confirm ascites and help diagnose the cause and to determine if the fluid is infectious.[20][21]
Diagnostic paracentesis should be performed on admission in all patients with cirrhosis and ascites and in hospitalised patients with ascites, even in the absence of symptoms or signs of infection.[20][21] Patients with ascites who develop signs, symptoms, or laboratory abnormalities suggestive of infection should undergo tests for infection plus a diagnostic abdominal paracentesis to rule out spontaneous bacterial peritonitis.[20]
Routine tests analysing ascitic fluid are cell count and differential, albumin concentration, total protein concentration, and culture in blood culture bottles. Ascites polymorphonuclear leukocyte (PMN) count >250/mm³ indicates spontaneous bacterial peritonitis and need for urgent antibiotic treatment.[20][21]
Cultures can help to direct targeted antibiotic therapy. However, cultures are not always positive, and are not required to establish a diagnosis of spontaneous bacterial peritonitis.[22]
Antibiotics remain the mainstay of treatment for spontaneous bacterial peritonitis.[20][22] The ascitic fluid should be cultured at the bedside in aerobic and anaerobic blood culture bottles before giving antibiotics.[20] Treatment should also include albumin; albumin improves survival in patients with cirrhosis and spontaneous bacterial peritonitis.[20]
A very high PMN count with high lactate dehydrogenase or a positive Gram stain or culture for multiple different organisms might suggest perforative peritonitis (secondary bacterial peritonitis). If perforative peritonitis is suspected, the threshold for computed tomography imaging should be low, as this is considered a surgical emergency.
Patients who have experienced an episode of spontaneous bacterial peritonitis are at high risk of recurrence; long-term antibiotic prophylaxis should be initiated in these patients.[20]
Haemoperitoneum
Haemoperitoneum may be due to internal trauma or may occur in up to 5% to 15% of patients with hepatocellular carcinoma requiring transcatheter arterial embolisation.[23] Massive acute haemoperitoneum can result from a ruptured intraperitoneal varix and is an unusual complication requiring prompt surgery. Patients may present with sudden increase in ascites and abdominal pain with a significant drop in haematocrit.
Refractory ascites
Patients with refractory ascites (maximum diuretic doses not sufficient to control ascites or unacceptable adverse effects/complications with diuretic therapy) can be managed with large-volume paracentesis and albumin replacement or transjugular intrahepatic portosystemic shunt placement.
Short-term survival after development of refractory ascites in cirrhosis is poor. Therefore, these patients should be considered for a liver transplant.
Other options for refractory ascites include placement of a tunnelled catheter (PleurX™) or a peritoneovenous (Denver™) shunt. Both of these options have complications that limit their use. They are typically only considered for palliative use in patients who are not liver transplant candidates.[24][25]
Hepatic encephalopathy
Patients with ascites due to cirrhosis are prone to developing hepatic encephalopathy. Symptoms and signs may be very subtle initially. Symptoms vary from change in handwriting, altered sleep pattern, and confusion, to coma. Prompt identification and treatment with lactulose and rifaximin can prevent potentially fatal complications such as aspiration pneumonia. Potential precipitating factors (e.g., dehydration/acute kidney injury, spontaneous bacterial peritonitis, hypokalaemia, gastrointestinal bleeding, sepsis) should be investigated and corrected promptly.
Hepatorenal syndrome
Worsening of renal function in a patient with ascites might be due to hepatorenal syndrome, which requires urgent treatment. Decreasing urine output and/or rising serum creatinine would suggest hepatorenal syndrome in patients with cirrhosis (hepatorenal syndrome-acute kidney injury [HRS-AKI], formerly known as type I HRS [HRS-1]).
HRS results from portal hypertension, in which systemic and splanchnic arterial vasodilation results in lower blood pressure and an overall decrease in effective circulatory volume. The kidney perceives a lower circulating volume, leading to compensatory renal artery vasoconstriction.[26] This leads to reduced glomerular filtration rate and decreased renal perfusion, causing kidney injury and development of HRS.
Patients with spontaneous bacterial peritonitis and alcohol-related liver disease are prone to developing HRS. Treatment is aimed at increasing renal pressure to allow for regression of kidney injury. Administer intravenous albumin along with a vasoconstrictor, such as terlipressin (a vasopressin analogue).[11][27][28]
[ 
]
If terlipressin is not available, midodrine and somatostatin, or noradrenaline, may be used.[20] In spontaneous bacterial peritonitis, treatment of the underlying infection is necessary. All patients with cirrhosis and AKI should be considered for urgent liver transplant evaluation given the high short-term mortality (even in responders to vasoconstrictor).[20]
Use of this content is subject to our disclaimer