• Prothrombin time (PT)/
  international normalized ratio (INR) and
  activated partial thromboplastin time (APTT)
• Full blood count and reticulocyte count
• Blood glucose
• Sodium, potassium, urea and creatinine (urea may be low because of reduced hepatic synthesis; if markedly elevated with a normal creatinine, suspect upper gastrointestinal bleeding)
• Liver function tests: bilirubin, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase, alkaline phosphatase, albumin
• Amylase and lipase
• Paracetamol level if unexplained acute liver failure or paracetamol poisoning is suspected
• Arterial blood gases, pH, lactate and ammonia
• Blood culture
• Urine stick test, microscopy and culture
• Microscopy and culture of ascites if present (aspirate 10 mL for cell count (use EDTA tube) and culture (inoculate blood culture bottles) (see Chapter 24)
• Chest X-ray
• Ultrasound of liver, biliary tract and hepatic/portal veins
• Pregnancy test in women of childbearing age

For later analysis

• Markers of viral hepatitis (anti-HAV IgM, HBsAg, anti-HBc IgM, anti-HCV, anti-HDV, anti-HEV, anti-HSV, anti-VZV)
• HIV test
• Autoimmune profile (antinuclear antibodies, antismooth muscle antibodies, immunoglobulins)
• Plasma ceruloplasmin in patients aged <50 (to exclude Wilson's disease)
• Serum (10 mL) and urine (50 mL) for toxicological analysis if needed
• Blood group and screen