Metabolic acidosis
Formula
- PCO2 = (1.5 x [HCO3–] + 8) ± 2
- In acute setting PCO2 falls by 1 mmHg for every 1 mEq fall in HCO3
DDX
Gap
- Lactic acidosis
- Renal failure
- Ketoacidosis
- DM
- ETOH
- Starvation
- High fat diet
- Tox ingestion
- Inc osm gap
- Methanol
- Ethylene glycol
- Nl osm gap
- Salicylate
- Paraldehyde
- Cyanide
- Inc osm gap
Non-gap
- Hyperkalemia
- Resolving DKA
- Early uremic acidosis
- Early obstructive
- RTA Type IV
- Hypoaldo
- K-sparing diuretics
- Hypokalemia
- RTA Type I
- RTA Type II
- Acetazolamide
- Acute diarrhea
- (May be assoc with gap if hypoperfusion -> lactic acidosis)
Treatment
Treat source
Bicarbonate Indications
- Bicarb <4
- pH <7.10 + Sx shock/myocardial irritability
- Severe hyperchloremic acidemia + Sx shock/myocardial irritability
Source
2/21/06 DONALDSON (adapted from Tintinalli)
