Severity of liver disease:
(1) previous episodes of cirrhosis
(2) absence of hepatomegaly (reflecting shrunken organ)
(3) presence of esophageal varices
(4) poor nutritional status
Renal function:
(1) moderately reduced glomerular filtration rate (< 80 mL/min)
(2) moderately increased BUN (> 15 mg/dL)
(3) moderately increased serum creatinine (> 0.9 mg/dL)
Electrolyte disturbances:
(1) low serum sodium (<= 133 mEq/L)
(2) low urinary sodium excretion (<= 2 mEq/L)
(3) high serum potassium (> 4 mEq/L)
(4) low baseline serum osmolality (reflects hyponatremia; <= 279 mOsm per kg water)
(5) high baseline urine osmolality (> 553 mOsm per kg water)
(6) reduced free water excretion after a water load (<= 3.3 mL/min)
Endocrine and Vascular:
(1) low arterial blood pressure (need to exclude gastrointestinal hemorrhage)
(2) low mean arterial blood pressure (<= 85 mm Hg)
(3) high plasma renin activity (> 3.5 ng/mL•h)
(4) increased plasma norepinephrine (> 544 pg/mL)
Differential diagnosis:
• Gastrointestinal bleeding from varices might present with increased BUN and hypotension.
Limitations:
• Some measurements (plasma renin, plasma norepineprine) may show intra-laboratory variability.
