What are the key investigations to consider for a patient presenting with jaundice in primary care?

For a patient presenting with jaundice in primary care, the key investigations to consider include:

• Serum bilirubin measurement to confirm jaundice and assess severity.
• Liver function tests (LFTs) including alanine transaminase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and total bilirubin to differentiate hepatitic, cholestatic, or obstructive patterns.
• Clotting profile to assess for coagulopathy.
• Renal function tests to evaluate kidney involvement.
• Full blood count to check for anaemia or infection.
• Blood group and direct antiglobulin test (Coombs' test) especially in newborns or if haemolysis is suspected.
• Serological tests for viral hepatitis (hepatitis A, B, C) if viral hepatitis is suspected.
• Additional tests such as alpha-fetoprotein and hepatic ultrasound may be arranged in secondary care if indicated.

In primary care, most patients with unexplained jaundice should be referred urgently for secondary care assessment due to the potential seriousness of underlying causes such as malignancy or severe liver disease. However, well patients with known Gilbert's syndrome or confirmed hepatitis A may be managed in primary care with appropriate investigations and monitoring.

Referral pathways depend on the pattern of LFT abnormalities: cholestatic or obstructive patterns warrant referral to gastroenterology or surgery; hepatitic patterns require urgent liver clinic referral; suspected alcohol-related or inherited liver diseases require specialist referral.

For patients aged 40 years and over presenting with jaundice, urgent referral via a suspected cancer pathway is recommended to exclude pancreatic cancer.

In summary, initial investigations in primary care focus on confirming jaundice, characterising liver injury, excluding coagulopathy and renal impairment, and screening for viral hepatitis, with prompt referral for further imaging and specialist assessment as indicated.

References: ¹,³,⁵