1. What is the SpO2 to PaO2 Conversion?

The SpO2 to PaO2 conversion provides an estimated arterial oxygen partial pressure (PaO2) from peripheral oxygen saturation (SpO2) measurements. This approximation is useful in clinical settings where direct arterial blood gas measurement is not available.

2. How Does the Calculator Work?

The calculator uses the approximation formula:

Where:

• \( SpO2 \) — Peripheral oxygen saturation (%)
• \( PaO2 \) — Estimated arterial oxygen partial pressure (mmHg)

Explanation: This linear approximation provides a rough estimate of PaO2 based on SpO2 measurements, though individual variations may occur.

3. Importance of PaO2 Estimation

Details: PaO2 estimation helps assess oxygenation status and can guide clinical decisions when arterial blood gas analysis is not immediately available.

4. Using the Calculator

Tips: Enter SpO2 percentage value (0-100%). The calculator will provide an estimated PaO2 value in mmHg.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this estimation?
A: This is an approximation and may not be accurate for all individuals, especially those with abnormal oxygen-hemoglobin dissociation curves.

Q2: When should arterial blood gas be measured instead?
A: For precise clinical decisions, direct arterial blood gas measurement is recommended, especially in critical care settings.

Q3: What factors affect the SpO2-PaO2 relationship?
A: Temperature, pH, 2,3-DPG levels, and hemoglobin variants can shift the oxygen-hemoglobin dissociation curve.

Q4: What are normal PaO2 values?
A: Normal arterial PaO2 is typically 80-100 mmHg at sea level, decreasing with age and altitude.

Q5: Can this be used for clinical decision making?
A: This should be used as a screening tool only. Critical decisions should be based on actual arterial blood gas measurements.