PF Ratio Calculator

Formula

To calculate the PF Ratio (R):

\[ R = \frac{PaO2}{FiO2 / 100} \]

Where:

\(R\) is the PF ratio
\(PaO2\) is the partial pressure of oxygen in arterial blood (mmHg)
\(FiO2\) is the fraction of inspired oxygen (%)

What is PF Ratio?

The PF ratio, or PaO2/FiO2 ratio, is a measure used to assess lung function, particularly in patients with respiratory issues such as acute respiratory distress syndrome (ARDS). It is calculated by dividing the partial pressure of oxygen in arterial blood (PaO2) by the fraction of inspired oxygen (FiO2).

Example Calculation 1

Let's assume the following values:

PaO2 = 80 mmHg
FiO2 = 40%

Using the formula:

\[ R = \frac{80}{40 / 100} = 200 \]

The PF ratio is 200.

Example Calculation 2

Let's assume the following values:

PaO2 = 100 mmHg
FiO2 = 50%

Using the formula:

\[ R = \frac{100}{50 / 100} = 200 \]

The PF ratio is 200.