Blood Gas Interpreter
Interpret acid-base balance from blood gas values.
Input Parameters
Enter measured blood gas values.
Acid-Base Balance and Physiological Arterial Blood Gas (ABG) Interpretation
Physiological Principles & Clinical Context
Maintaining acid-base homeostasis is vital for vascular tone, myocardial contractility, cellular enzyme kinetics, and normal central nervous system function. During cardiopulmonary bypass, the perfusionist acts as the primary controller of acid-base balance by adjusting the sweep gas flow rate (governing pCO₂ clearance) and administering basic buffers like sodium bicarbonate. Acid-base analysis is based on the Henderson-Hasselbalch relationship, which models blood pH as a function of metabolic (bicarbonate) and respiratory (carbon dioxide) parameters, allowing rapid identification of acidosis, alkalosis, and compensatory responses.
Clinical Targets & Safe Ranges
- •Physiological Blood pH Target: 7.35 to 7.45
- •Physiological Arterial pCO₂ Target: 35 to 45 mmHg (or temperature-corrected depending on strategy).
- •Physiological Serum Bicarbonate (HCO₃⁻) Target: 22 to 26 mEq/L
- •Physiological Base Excess (BE) Range: -2.0 to +2.0 mEq/L
Mathematical Formulation
- ƒHenderson-Hasselbalch Equation: pH = 6.1 + log [ HCO₃⁻ / (0.0301 × pCO₂) ]
- ƒAlveolar Gas Equation (for reference): PaO₂ = FiO₂ × (Pb - PH₂O) - (PaCO₂ / R)
- ƒAnion Gap (Standard): Anion Gap = [Na⁺] - ( [Cl⁻] + [HCO₃⁻] )
Academic & Clinical References
- Henderson LJ. Das Gleichgewicht zwischen Basen und Säuren im tierischen Organismus. Ergebnisse der Physiologie. 1909;8(1):254-325.
- Hasselbalch KA. Die Berechnung der Wasserstoffzahl des Blutes aus der freien und gebundenen Kohlensäure desselben. Biochemische Zeitschrift. 1916;78:112-144.
- Siggaard-Andersen O. The Acid-Base Status of the Blood. Copenhagen: Munksgaard; 1974.
Medical Disclaimer
This application is intended for educational and reference purposes for qualified perfusionists and cardiac surgical professionals. The clinical information and calculations provided should not substitute for professional clinical judgment or institutional protocols. Always verify results with independent calculations and equipment. Perfi does not assume liability for clinical decisions made based on this software.