×
MedSchool: Ace Your OSCEsThe Medical Company
 
 
 
 
 
GET - On the App Store
View
ABG Interpretation
 
ABG Interpretation
 

Metabolic Acidosis

 
 
 
Bookmark

Overview

Metabolic acidosis is a process in which an external agent or internal process is causing excessive acidity in a way that is metabolic (i.e. non-respiratory).
  • Look For

  • Acidaemia with reduced bicarbonate.
  • Expected Compensation

  • Decrease in PaCOâ‚‚ = 1.5 x HCO₃ + 8
  • Causes of Metabolic Acidosis

  • Ingestion of acid - methanol, ethylene glycol, salicylic acid
  • Acid production - lactic acidosis, ketoacidosis, rhabdomyolysis
  • Reduced acid excretion - renal failure, distal RTA
  • Loss of alkali - diarrhoea, proximal RTA
  • Approach

  • Check the anion gap to further distinguish between causes.

High Anion Gap Metabolic Acidosis

Metabolic acidosis with raised anion gap.
  • Causes of High Anion Gap Metabolic Acidosis

  • Endogenous

  • Lactic acidosis
  • Ketoacidosis - diabetic, alcoholic
  • Uraemia (end-stage renal failure)
  • Exogenous

  • Methanol / ethanol / ethylene glycol
  • Salicylates
  • Cyanide
  • Carbon monoxide

Normal Anion Gap Metabolic Acidosis

Metabolic acidosis without raised anion gap.
  • Causes of Normal Anion Gap Metabolic Acidosis

  • GI loss - diarrhoea, fistula, stoma
  • Isotonic saline infusion
  • Renal tubular acidosis (proximal)
  • Acetazolamide
  • Addison's Disease
Next Page
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now
   
 
 

Snapshot: Initialising...