Metabolic Acidosis & Alkalosis

• The GOLD MARK mnemonic covers high anion gap acidosis: glycols, oxoproline, L/D-lactate, methanol, aspirin, renal failure, ketoacidosis.
• Use the delta ratio to uncover mixed disorders; only normalize pH in select scenarios (TCA, salicylate, severe DHA).
• Metabolic alkalosis splits into chloride-responsive (vomiting, diuretics → saline) and chloride-resistant (hyperaldosteronism).
• Give bicarbonate selectively, never routinely; fix the cause.
• Bicarbonate is not recommended in DKA.

Working Through Metabolic Acidosis and Alkalosis

• Primary disorder on the blood gas?
• PRIMARY METABOLIC ACIDOSIS — pH <7.4, serum HCO₃⁻ <24 mEq/L
• Appropriate respiratory compensation?
• Address the respiratory component if necessary — life-threatening acid–base disturbances unable to fully hyper- or hypoventilate may require intubation and mechanical ventilation
• pH life-threatening?
• Give bicarbonate/hemodialysis
• Check AG, delta AG — combined disorder?
• Treat by order of clinical importance
• Simple non-AG acidosis (see text/Tables 25.2 and 25.4) OR simple AG acidosis (see text/Tables 25.2 and 25.3) → check the urine anion gap (UAG)
• PRIMARY METABOLIC ALKALOSIS — pH >7.4, serum HCO₃⁻ >24 mEq/L
• Appropriate respiratory compensation?
• Address the respiratory component if necessary
• Check AG, delta AG — combined disorder?
• Treat by order of clinical importance
• Single disorder → check the urine Cl⁻