⚗️ Henderson–Hasselbalch (pH from HCO₃/PaCO₂)
UseWhen to use: check ABG consistency or estimate pH from known HCO₃/PaCO₂.
StrataDeviations from measured pH suggest lab inconsistency, temperature effects, or mixed disorders needing full w…
LimitsWhen not to use: replacing a measured ABG pH for decisions. · Pitfall: wrong solubility coefficient units. · Not full acid-base diagnosis.
SourceStandard Henderson–Hasselbalch plasma equation
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
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Methodology · worked example, guidelines & full notes
6.1+log10(HCO₃/(0.0301×PCO₂)).
When to use
When to use: check ABG consistency or estimate pH from known HCO₃/PaCO₂.
How it works
pH = 6.1 + log₁₀([HCO₃]/(0.0301×PaCO₂)).
Key points
- 6.1+log10(HCO₃/(0.0301×PCO₂)).
- CO₂–HCO₃ equilibrium.
- Next: AG / BE.
References
- Standard Henderson–Hasselbalch plasma equation
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| HCO₃⁻ | 24 mmol/L |
|---|---|
| PaCO₂ | 40 mmHg |
→Calculated pH7.40
- HCO₃/(0.0301×PaCO₂)：19.93
- Dissolved CO₂：1.20 mmol/L
- Cue：Near-normal pH teaching band
Verification & sources · governance
FAQ
Frequently asked questions
- Does Henderson–Hasselbalch (pH from HCO₃/PaCO₂) upload patient data? Where is it calculated?
- Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
- How is Henderson–Hasselbalch (pH from HCO₃/PaCO₂) calculated in practice? Can you show a worked example?
- Inputs: HCO₃⁻ 24 mmol/L, PaCO₂ 40 mmHg → Result: Calculated pH 7.40（HCO₃/(0.0301×PaCO₂): 19.93, Dissolved CO₂: 1.20 mmol/L, Cue: Near-normal pH teaching band）