Understanding Acidosis and Alkalosis

Overview

• Health Issue: Determining if blood is acidic (acidosis) or basic (alkalosis).
• Normal Blood pH: 7.35 - 7.45.
  • Below 7.35: Acidosis.
  • Above 7.45: Alkalosis.

pH Measurement in Blood

• pH: Measures hydrogen ion concentration.
• Blood Tests: Look beyond pH to determine if condition is respiratory or metabolic.

Key Equation

• CO2 + H2O → H2CO3 (Carbonic acid)
  • Carbonic acid dissociates into HCO3⁻ (bicarbonate ion) and H⁺ (hydrogen ions).
  • Increase in H⁺: Acidosis.
  • Decrease in H⁺: Alkalosis.

Types of Acidosis and Alkalosis

Respiratory-Based

• Respiratory Acidosis:
  • Increase in CO2 leads to more carbonic acid, splitting into more H⁺.
  • pH drops (more acidic).
• Respiratory Alkalosis:
  • Decrease in CO2 means less carbonic acid and fewer H⁺.
  • Relative increase in bicarbonate.
  • pH increases (more basic).

Metabolic-Based

• Metabolic Acidosis:
  • Increase in H⁺ or decrease in bicarbonate.
  • Results in a drop in bicarbonate and pH (uncompensated).
• Metabolic Alkalosis:
  • Increase in bicarbonate or decrease in H⁺.
  • Results in pH increase (uncompensated).

Summary

• Respiratory Acidosis-Alkalosis: Related to CO2 levels and its effect on pH.
• Metabolic Acidosis-Alkalosis: Related to bicarbonate and H⁺ balance.
• Important to check pH, bicarbonate, and CO2 levels to diagnose the condition.