How to Calculate Venous Blood pH

The Venous Blood pH Calculator estimates the acidity (pH) of venous blood using the Henderson-Hasselbalch equation, which is based on bicarbonate (HCO₃⁻) and venous carbon dioxide partial pressure (PaCO₂). The formula used is:

Where:

• \( [\text{HCO}_3^-] \): Bicarbonate concentration in the blood (in mEq/L or mmol/L, normal range: 23-30 mEq/L).
• \( \text{PaCO}_2 \): Partial pressure of carbon dioxide in venous blood (in mmHg, normal range: 41-51 mmHg).

Enter the bicarbonate and PaCO₂ values to compute the venous blood pH.

Using the Venous Blood pH Calculator

This calculator is designed to assist healthcare professionals in assessing acid-base balance and diagnosing conditions such as acidosis or alkalosis by estimating venous blood pH.

Input the bicarbonate concentration (in mEq/L) and PaCO₂ (in mmHg). The calculator will display the venous blood pH value and indicate whether it suggests acidosis, alkalosis, or normal pH.

Normal pH Ranges:

• Normal venous blood pH: 7.31-7.41
• Acidosis: pH < 7.31 (too acidic)
• Alkalosis: pH > 7.41 (too alkaline)

Example: Calculate the pH for bicarbonate = 25 mEq/L and PaCO₂ = 45 mmHg.

1. Bicarbonate: \( 25 \, \text{mEq/L} \)
2. PaCO₂: \( 45 \, \text{mmHg} \)
3. Calculation: \( \text{pH} = 6.1 + \log_{10}\left(\frac{25}{0.03 \times 45}\right) = 6.1 + \log_{10}\left(\frac{25}{1.35}\right) = 6.1 + \log_{10}(18.5185) \approx 6.1 + 1.2676 = 7.3676 \)
4. Result: Venous blood pH ≈ 7.37 (Normal)

Use this tool for quick and accurate pH calculations in clinical settings, but consult a healthcare provider for diagnosis and treatment decisions.