Acid-Base Mnemonic by Dr. Barone

Overview

• This mnemonic helps determine if an acid-base disorder is metabolic or respiratory.
• Developed by Dr. Cook.

Key Concept

• The mnemonic uses the letters MD:
  • Metabolic
  • Direct
• Metabolic, Direct: When pH and CO2 are directly related (both up or both down), it is metabolic.
• When pH and CO2 are inversely related, it is respiratory.

Examples

1. Metabolic

   • If pH is down (acidosis) and CO2 is down:
     • Both parameters are down → Metabolic Acidosis
   • If pH is up (alkalosis) and CO2 is up:
     • Both parameters are up → Metabolic Alkalosis

2. Respiratory

   • If pH is down and CO2 is up:
     • Parameters are inversely related → Respiratory Acidosis
   • If pH is up and CO2 is down:
     • Parameters are inversely related → Respiratory Alkalosis

Summary

• Same direction (pH and CO2) → Metabolic
• Opposite direction (pH and CO2) → Respiratory
• Simple and easy to remember.