Serum Ascites Albumin Gradient (SAAG)
Differentiates portal hypertension-related (transudative) from non-portal hypertension (exudative) causes of ascites. SAAG = serum albumin − ascites albumin.
Score interpretation
SAAG < 11 g/L: Ascites NOT caused by portal hypertension.
→ Consider: peritoneal malignancy, TB peritonitis, pancreatitis, nephrotic syndrome, serositis. Send ascitic fluid for cytology, AFB, culture, amylase. Oncology/specialist review.
SAAG ≥ 11 g/L: Portal hypertension likely (97% accuracy). Causes: cirrhosis, cardiac failure, Budd-Chiari, portal vein thrombosis.
→ Investigate portal hypertension cause. Liver USS + Doppler. Liver function tests, hepatitis screen. If cirrhosis: start spironolactone ± furosemide. Salt restriction (< 5g/day). SBP prophylaxis if recurrent ascites.
Interpretation bands for the SAAG. Apply clinical judgement and local guidance.
References
- Runyon BA, et al. The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites. Ann Intern Med. 1992;117(3):215–220.
Related
Curated clinical cross-links plus same-class fallbacks.
- Propranolol (Portal Hypertension) · Antihypertensive
- Spironolactone (Ascites / Cirrhosis) · Aldosterone Antagonist / Potassium-Sparing Diuretic
- Furosemide (Ascites / Cirrhosis) · Loop Diuretic
- Carvedilol (Portal Hypertension) · Non-Selective Beta-Blocker with Alpha₁-Blocking Activity
- Selexipag · Pulmonary Arterial Hypertension
- Macitentan · Pulmonary Arterial Hypertension
- Upper GI Bleeding · BSG Guidelines 2019; NICE NG141
- Lower Gastrointestinal Bleed · NICE; BSG; ACPGBI — Commissioning Guide
- Acute Pancreatitis · NICE; IAP/APA; ACPGBI — CG104
- Sepsis Screening and Sepsis Six · UK Sepsis Trust; NICE NG51; Surviving Sepsis Campaign 2021
- Unintentional Weight Loss Workup · NICE NG12; BSG
- Chronic Fatigue Workup · NICE NG206; BMJ Best Practice
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.