Medical Education Tool
ABG Tutor / Tic-Tac-Toe
Arterial blood gas interpretation and compensation recognition
Interactive Practice
Practice Controls
Disabled
Case ABG Values
pH
—
PaCO2
—
mmHg
HCO3-
—
mEq/L
PaO2
—
mmHg
Press Generate Case to begin a new ABG scenario.
Normal Reference Ranges
| pH | 7.35 to 7.45 |
| PaCO2 | 35 to 45 mmHg |
| HCO3- | 22 to 26 mEq/L |
| PaO2 | 80 to 100 mmHg |
| Compensation Formulas | |
| Metabolic Acidosis | Winter's: PaCO2 = 1.5 × HCO3- + 8 ±2 |
| Metabolic Alkalosis | PaCO2 = 0.7 × (HCO3- − 24) + 40 ±5 |
| Resp Acidosis | HCO3- ↑ 3.5 per 10 mmHg CO2 (chronic) |
| Resp Alkalosis | HCO3- ↓ 5 per 10 mmHg CO2 (chronic) |
Classification Grid
Click each cell to classify the value as Acidic, Normal, or Alkaline.
| Acidic | Normal | Alkaline | |
|---|---|---|---|
| pH | < 7.35 |
7.35 to 7.45 |
> 7.45 |
| PaCO2 | > 45 |
35 to 45 |
< 35 |
| HCO3- | < 22 |
22 to 26 |
> 26 |
Note: For PaCO2, elevated is acidic and decreased is alkaline (inverse of pH direction).
Your Interpretation
