Metabolic Acidosis
| Non-Anion-Gap Acidosis | Anion-Gap Acidosis | ||
|---|---|---|---|
| Cause | Clue | Cause | Clue |
Diarrhea enterostomy RF RTA Proximal Distal—hypokalemic Distal—hyperkalemic Distal—hyporeninemic hypoaldosteronism Dilutional Ureterosigmoidostomy Hyperalimentation Acetazolamide, NH4Cl, lysine HCl, arginine HCl, sevelamer-HCl | Hx; ↑ K+ drainage Early chronic kidney disease
↓K+, presence of other proximal tubular defects (Fanconi syndrome) ↓K+; hypercalciuria; UpH >5.5 ↑K+; nl PRA/aldo; UpH >5.5 ↑K+; ↓ PRA/aldo; UpH <5.5 Massive volume expansion with saline Obstructed ileal loop Amino acid infusion Hx of administration of these agents | DKA RF Lactic acidosis (L-lactate) Alcoholic ketoacidosis Starvation Salicylates Methanol
Ethylene glycol
D-lactic acidosis Propylene glycol Pyroglutamic aciduria, 5-oxoprolinuria | Hyperglycemia, ketones Late chronic kidney disease Clinical setting + ↑ serum lactate
Hx; weak + ketones; + osm gap Hx; mild acidosis; + ketones Hx; tinnitus; high serum level; + ketones; + lactate Large AG; concomitant respiratory alkalosis; retinitis; + toxic screen; + osm gap
RF; CNS symptoms; + toxic screen; crystalluria; + osm gap Small-bowel disease; prominent neuro symptoms IV infusions, e.g., lorazepam; + osm gap; RF Large AG; chronic acetaminophen |
Abbreviations: AG, anion gap; DKA, diabetic ketoacidosis; osm gap, osmolar gap; PRA, plasma renin activity; RF, renal failure; RTA, renal tubular acidosis; UpH, urinary pH.