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💧 Electrolyte-Free Water Clearance (EFWC)

UseWhen to use: hyponatremia / free-water balance assessment with timed urine volume.

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StrataPositive EFWC → free-water loss; negative → retention.

LimitsWhen not to use: incomplete urine collection. · Pitfall: ignoring ongoing intake. · Not an ODS-risk calculator alone.

SourceStandard electrolyte-free water clearance teaching formula

Runs locally in your browser (no PHI uploaded). For licensed clinicians — not a substitute for clinical judgement.
Stored on this device for revisit reminders

This-shift next steps

After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.

Scene next step
📋electrolyteOpen scene pack →
Related scores
Matching pathway
🧭hyperkOpen pathway →
Score + version; reference only — not a substitute for care · no HIS write

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Methodology · worked example, guidelines & full notes
Clinical takeaway

EFWC formula.

When to use

When to use: hyponatremia / free-water balance assessment with timed urine volume.

How it works

EFWC = V̇u × (1 − (UNa + UK)/PNa).

Key points

  • EFWC formula.
  • Sign matters.
  • Next: tonicity plan.

References

  • Standard electrolyte-free water clearance teaching formula

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.

Urine volume rate100 mL/h
Urine Na40 mEq/L
Urine K30 mEq/L
Plasma Na130 mEq/L

→EFWC46.2mL/h

  • (UNa+UK)/PNa：0.54
  • Cue：Nearer modest EFWC band
Verification & sources · governance
FAQ

Frequently asked questions

Does Electrolyte-Free Water Clearance (EFWC) 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 Electrolyte-Free Water Clearance (EFWC) calculated in practice? Can you show a worked example?
Inputs: Urine volume rate 100 mL/h, Urine Na 40 mEq/L, Urine K 30 mEq/L, Plasma Na 130 mEq/L → Result: EFWC 46.2 mL/h（(UNa+UK)/PNa: 0.54, Cue: Nearer modest EFWC band）
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