Acidosis resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Rim Halaby
Overview
Acidosis occurs when the pH is less or equal to 7.35 due to excess of hydrogen ions.
Causes
Life Threatening Causes
Common Causes
- Diabetic ketoacidosis
- Diarrhea
- Ethylene glycol
- Lactic acidosis
- Methanol
- Renal tubular acidosis
- Salicylates
- Uremia
Management
| pH < 7.35 | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Acidosis (High [H+]) | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Determine the primary disorder Metabolic or respiratory? | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Check [HCO3-] and PaCO2 | |||||||||||||||||||||||||||||||||||||||||||||||||||
| Low [HCO3-] and Low to normal PaCO2 | High PaCO2 and High to normal [HCO3-] | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Metabolic acidosis | Respiratory acidosis | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Check for respiratory compensation Calculate expected PCO2 | Check for renal compensation Calculate expected [HCO3-] | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Decrease in PaCO2=1.25 x (24- measured HCO3-)? | Acute acidosis? Increase [HCO3-]=0.1 x (measure PaCO2-40)? | Chronic acidosis? Increase [HCO3-]=0.1 x (measure PaCO2-40)? | |||||||||||||||||||||||||||||||||||||||||||||||||
| PaCO2 too low? Mixed metabolic acidosis with respiratory alkalosis | PaCO2 too high? Mixed metabolic acidosis with respiratory acidosis | [HCO3-] too low? Mixed respiratory acidosis with metabolic acidosis | [HCO3-] too high? Mixed respiratory acidosis with metabolic alkalosis | [HCO3-] too low? Mixed respiratory acidosis with metabolic acidosis | E04=[HCO3-] too high? Mixed respiratory acidosis with metabolic alkalosis | ||||||||||||||||||||||||||||||||||||||||||||||
| Measured PaCO2 is equal to expected value? Compensated metabolic acidosis | Measured [HCO3-] is equal to expected value? Compensated respiratory acidosis | Measured [HCO3-] is equal to expected value? Compensated respiratory acidosis | |||||||||||||||||||||||||||||||||||||||||||||||||
| Click here for the management of metabolic acidosis | Click here for the management of respiratory acidosis | ||||||||||||||||||||||||||||||||||||||||||||||||||