Source: https://guthlabs.ai/docs/instruments/corrected-calcium-sodium-calculator/mechanism/

instrument mechanism / verified-clean

# Corrected Calcium / Sodium Calculator mechanism

The inspectable method record for Corrected Calcium / Sodium Calculator, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The formulas are arithmetically correct under the stated unit assumptions, and the educational-only/not-medical-advice label is appropriate. Review is required to specify units, input pairing, and the intended sodium correction convention before release.

- The calcium formula is standard only when calcium is in mg/dL and albumin is in g/dL: CorrCa = Ca + 0.8 × (4 − albumin). Those units are not specified in the instrument spec.

- The sodium formula uses the Hillier correction coefficient of 2.4 mEq/L per 100 mg/dL glucose above 100 mg/dL. A coefficient of 1.6 is also commonly used, so the intended clinical convention must be explicitly named.

- The input description 'measured Ca or Na, albumin or glucose' is ambiguous about required input pairing and does not identify units.

## Units and conventions

- Calcium (Ca) is in mg/dL.

- Albumin is in g/dL, with a reference albumin of 4 g/dL.

- Sodium (Na) is in mEq/L (numerically equivalent to mmol/L for sodium).

- Glucose is in mg/dL for the stated sodium formula; glucose in mmol/L must be multiplied by 18 before calculation.

- The sodium correction coefficient is specifically the Hillier 2.4 convention.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "calcium_mg_dL": 8.2,
    "albumin_g_dL": 3,
    "sodium_mEq_L": 140,
    "glucose_mg_dL": 200
  },
  "expected_outputs": {
    "corrected_calcium_mg_dL": 9,
    "corrected_sodium_mEq_L": 142.4
  },
  "working": "Corrected calcium: 8.2 + 0.8 × (4 − 3.0) = 8.2 + 0.8 × 1.0 = 8.2 + 0.8 = 9.0 mg/dL. Corrected sodium: 140 + 2.4 × ((200 − 100) / 100) = 140 + 2.4 × (100 / 100) = 140 + 2.4 × 1 = 142.4 mEq/L."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

An extreme glucose input near the JavaScript floating-point limit causes the subtraction of 100 to be lost and the final result to lose low-order precision. The instrument specification also provides no input-range validation for zero or extreme values.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/corrected-calcium-sodium-calculator/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/corrected-calcium-sodium-calculator/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/corrected-calcium-sodium-calculator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`