Fractional Excretion of Sodium (FENa)

FENa to distinguish prerenal AKI from ATN.

How to use

Call with the inputs below. Boolean inputs are optional (absent = false). Returns the value, an interpretation, and a breakdown. Deterministic — no network call.

Parameters

Name	Type		Description
urine_sodium	number	required	Urine sodium — unit: mEq/L
plasma_sodium	number	required	Plasma sodium — unit: mEq/L
urine_creatinine	number	required	Urine creatinine — unit: mg/dL
plasma_creatinine	number	required	Plasma creatinine — unit: mg/dL

Example input

{
  "urine_sodium": 20,
  "plasma_sodium": 140,
  "urine_creatinine": 50,
  "plasma_creatinine": 2
}

Example output

{
  "calculator": "Fractional Excretion of Sodium (FENa)",
  "category": "Renal",
  "value": "0.57 %",
  "interpretation": "Suggests prerenal AKI (<1%).",
  "severity": "moderate",
  "notes": [
    "Not valid after diuretics — use FEUrea instead."
  ]
}

Call it (MCP tools/call)

{
  "method": "tools/call",
  "params": {
    "name": "calc_fena",
    "arguments": {
      "urine_sodium": 20,
      "plasma_sodium": 140,
      "urine_creatinine": 50,
      "plasma_creatinine": 2
    }
  }
}

Endpoint: POST https://clinical-mcp.mcharge.in/mcp (Streamable HTTP).