SAICA Biochemistry Profiles

Biochemistry Profiles


Specimen	Name	Result	Units	Range

Plasma	Sodium	126	mmol/L	(135-145)
	Potassium	5.2	mmol/L	(3.5-5.5)
	Chloride	100	mmol/L	(100-109)
	Bicarbonate	15	mmol/L	(22-32)
	Glucose	5.6	mmol/L	(3.8-5.5)
	Urea	18.0	mmol/L	(2.7-7.2)
	Creatinine	260	μmol/L	(60-110)
	Osmolality	279	mmol/kg	(275-295)

76yo male with general malaise / lethargy.

SIADH or Addison's Not hypo-osmolar, however ... Hypo-osmolar Hyponatraemia: Sodium loss (> water) → hypovolaemia Water excess excess hypotonic fluids CCF nephrotic syndrome cirrhosis SIADH Causes of hyponatraemia & hyperkalaemia (Na⁺:K⁺ ratio < 25:1): Addison's - hypo-osmolar, mild uraemia K⁺-sparing diuretics DKA - hyper-osmolar, hyperglycaemia Renal failure - esp. salt-losing nephritis, hypo-osmolar & uraemia ACE Inhibitors (rarely) - Entresto® Criteria for SIADH** Hypo-osmolar Hyponatraemia Urinary [Na⁺] > 20 mmol/L Urine hypertonic c.f. plasma Normal renal, adrenal, cardiac and hepatic function Absence of drugs causing "SIADH" i.e. drug-induced SIADH ≠ true SIADH Corrected by water restriction alone.