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Alveolar Gas Equation (PAO2) & A-a Gradient Calculator

Easily calculate and compute alveolar gas equation (pao2) & a-a gradient calculator with accurate equations, live formulas, and expert guidance.

Calculated Result
99.7 mmHg

Alveolar Oxygen Partial Pressure (PAO2)

Alveolar Oxygen Partial Pressure (PAO2)

99.7 mmHg

Arterial Alveolar Gradient Mm Hg

11.7

Measured Pa O2 Mm Hg

88

Expected Normal Aa Gradient

12

Expected Room Air P A O2 Mm Hg

100

99.7 — mmHg

Calculation Breakdown

  1. Applied FormulaCalculates theoretical alveolar oxygen partial pressure (PAO2) and the arterial-alveolar (A-a) oxygen gradient to distinguish hypoventilation from intrinsic pulmonary diffusion/shunt impairment.P_A O_2 = F_i O_2 (P_{\text{atm}} - P_{\text{H}_2\text{O}}) - \frac{P_a\text{CO}_2}{R}, \quad A\text{-}a = P_A O_2 - P_a O_2

Alveolar Gas PAO2 & A-a Metric Output

Interactive visualization based on your current inputs

Calculated Value
0.0255075100Alveolar Oxygen Partial Pressure (PAO2)

What Is the Alveolar Gas Equation (PAO2) & A-a Gradient Calculator?

This tool computes alveolar gas equation (pao2) & a-a gradient calculator with high precision arithmetic.

How Does the Alveolar Gas Equation (PAO2) & A-a Gradient Calculator Work?

Calculates theoretical alveolar oxygen partial pressure (PAO2) and the arterial-alveolar (A-a) oxygen gradient to distinguish hypoventilation from intrinsic pulmonary diffusion/shunt impairment.

Alveolar Gas Equation (PAO2) & A-a Gradient Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

PAO2=FiO2(Patm−PH2O)−PaCO2R,A-a=PAO2−PaO2P_A O_2 = F_i O_2 (P_{\text{atm}} - P_{\text{H}_2\text{O}}) - \frac{P_a\text{CO}_2}{R}, \quad A\text{-}a = P_A O_2 - P_a O_2

Calculates theoretical alveolar oxygen partial pressure (PAO2) and the arterial-alveolar (A-a) oxygen gradient to distinguish hypoventilation from intrinsic pulmonary diffusion/shunt impairment.

How to Use the Alveolar Gas Equation (PAO2) & A-a Gradient Calculator

  1. Enter your parameters into the designated input fields to calculate the result immediately.

Step-by-Step Example Calculation

Alveolar Gas Equation (PAO2) & A-a Gradient Calculator Example

Input Values:

fractionOfInspiredOxygenFiO2:0.21
arterialPaCO2MmHg:40
arterialPaO2MmHg:88
barometricPressureMmHg:760
Worked Steps: Sample evaluation based on standard reference conditions.

Understanding Your Result

The calculated primary figure indicates the optimal or required mmHg.

Factors That Affect the Result

  • Measurement tolerances, operational variance, and real-world conditions.

When Should You Use This Calculator?

  • Everyday budgeting, technical homework, professional estimation, and household projects.

Assumptions & Limitations

  • Assumes standard atmospheric or environmental parameters unless specified.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Double-precision IEEE 754 arithmetic with validated empirical constants.

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