1. What is the Henderson-Hasselbalch Equation?

The Henderson-Hasselbalch equation is a chemical equation used to calculate the pH of a buffer solution. In medicine, it's applied to arterial blood gas analysis to understand acid-base balance by relating pH to bicarbonate concentration and carbon dioxide partial pressure.

2. How Does the Calculator Work?

The calculator uses the Henderson-Hasselbalch equation:

Where:

• \( pH \) — Acid-base balance measurement (dimensionless)
• \( [HCO_3^-] \) — Bicarbonate concentration (mmol/L)
• \( pCO_2 \) — Partial pressure of carbon dioxide (mmHg)
• 0.03 — Conversion factor for CO₂ solubility
• 6.1 — pKa of carbonic acid at 37°C

Explanation: The equation describes the relationship between pH, bicarbonate, and carbon dioxide in the blood, helping clinicians assess acid-base disorders.

3. Importance of pH Calculation in Medicine

Details: Accurate pH calculation is essential for diagnosing and managing acid-base disorders such as metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis. It helps guide appropriate treatment in critical care settings.

4. Using the Calculator

Tips: Enter bicarbonate concentration in mmol/L and partial pressure of CO₂ in mmHg. Both values must be positive numbers. The calculator will compute the arterial pH value.

5. Frequently Asked Questions (FAQ)

Q1: What is the normal range for arterial pH?
A: Normal arterial pH ranges from 7.35 to 7.45. Values below 7.35 indicate acidosis, while values above 7.45 indicate alkalosis.

Q2: When is this equation most useful?
A: This equation is particularly useful in emergency medicine, intensive care, and anesthesiology for rapid assessment of acid-base status from arterial blood gas results.

Q3: Are there limitations to this equation?
A: While useful, the equation assumes ideal conditions and may not account for all clinical variables. It should be used in conjunction with clinical assessment and other laboratory findings.

Q4: What factors can affect the accuracy of the calculation?
A: Temperature, hemoglobin concentration, and other electrolytes can influence the relationship. The equation provides an estimate rather than an exact measurement.

Q5: How does this relate to respiratory and metabolic disorders?
A: The equation helps differentiate between respiratory disorders (primarily affecting pCO₂) and metabolic disorders (primarily affecting HCO₃⁻) in acid-base imbalances.