Metabolic Acidosis & Alkalosis

• The GOLD MARK mnemonic covers high anion gap acidosis: glycols, oxoproline, L/D-lactate, methanol, aspirin, renal failure, ketoacidosis.
• Use the albumin-corrected anion gap and the delta ratio to spot mixed disorders. Treat the cause; bicarbonate targets depend on the indication (e.g. sodium-channel-blocker or salicylate poisoning, or selected severe metabolic acidaemia) — not routine pH correction.
• Metabolic alkalosis splits into chloride-responsive (vomiting, diuretics → saline) and chloride-resistant (hyperaldosteronism).
• Give bicarbonate selectively, never routinely; fix the cause.
• No routine bicarbonate in DKA; the 2024 consensus allows it for severe acidosis with pH <7.0, with close K and blood-gas monitoring.

Metabolic acidosis

First tests: Venous blood gas, Sodium, potassium, bicarbonate, urea and creatinine, Blood lactate, Blood glucose.

Only if indicated: Blood beta-hydroxybutyrate, Measured serum osmolality, Urine electrolytes / urine pH.

Repeat monitoring: Venous blood gas.

Metabolic alkalosis

First tests: Venous blood gas, Sodium, potassium, bicarbonate, urea and creatinine, Magnesium.

Only if indicated: Urine chloride, Renin / aldosterone evaluation.

Repeat monitoring: Sodium, potassium, bicarbonate, urea and creatinine.

• Working Through Metabolic Acidosis and Alkalosis