Lecture on Reading Arterial Blood Gases (ABGs)

Overview

• Practice problems available at survivenursing.com/ABG
• Website generates 10 different ABG practice problems
• Click "Show Answers" to check results
• Reviewing how to interpret ABG values using a tic-tac-toe grid

Key Concepts

Tic-Tac-Toe Grid for ABGs

• Columns:
  • Acid
  • Normal
  • Base

Parameters

• pH:
  • Normal range:
  • Acidic if < 7.35
  • Basic (alkalotic) if > 7.45
• CO2:
  • Respiratory parameter
  • Normal range: 35-45 mmHg
  • Basic if < 35
  • Acidic if > 45
• HCO3 (Bicarbonate):
  • Metabolic parameter
  • Normal range: 22-26 mEq/L
  • Basic if > 26
  • Acidic if < 22

Problem Walkthroughs

Problem 1

• pH = 7.79: Basic (alkalotic)
• CO2 = 24: Basic
• HCO3 = 21: Acidic
• Diagnosis: Partially compensated respiratory alkalosis

Problem 2

• pH = 7.17: Acidic
• CO2 = 35: Normal
• HCO3 = 12: Acidic
• Diagnosis: Uncompensated metabolic acidosis

Problem 3

• pH = 7.45: Normal, leaning towards basic
• CO2 = 48: Acidic
• HCO3 = 28: Basic
• Diagnosis: Fully compensated metabolic alkalosis

Problem 4

• All values normal
• Diagnosis: Normal ABG

Problem 5

• pH = 7.63: Basic
• CO2 = 24: Basic
• HCO3 = Acidic
• Diagnosis: Partially compensated respiratory alkalosis

Problem 6

• pH = 7.33: Acidic
• CO2 = 22: Basic
• HCO3 = 21: Acidic
• Diagnosis: Partially compensated metabolic acidosis

Problem 7

• pH = 7.15: Acidic
• CO2 = 46: Acidic
• HCO3 = 34: Basic
• Diagnosis: Partially compensated respiratory acidosis

Problem 8

• pH = 7.54: Basic
• CO2 = 24: Basic
• HCO3 = 25: Normal
• Diagnosis: Uncompensated respiratory alkalosis

Problem 9

• All values normal
• Diagnosis: Normal ABG

Problem 10

• pH = 7.55: Basic
• CO2 = 20: Basic
• HCO3 = 19: Acidic
• Diagnosis: Partially compensated respiratory alkalosis

Conclusion

• Website is a useful resource for practicing ABG interpretation
• Refresh the page for new sets of problems and answers