Health

Dead Space Fraction (VD/VT, Bohr & Enghoff)

Calculate VD/VT using both the Bohr equation (PACO₂-based) and the Enghoff modification (PaCO₂-based). Normal ~0.20–0.40; >0.60 signals severe dead space in ARDS/PE. Derived from Bohr 1891, Enghoff 1938, Tusman 2012, LITFL, StatPearls. Not medical advice.

json· JSON resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/dead-space-fraction' \
  -H 'Content-Type: application/json' \
  -d '{"peco2":28,"paco2":40,"paco2Alveolar":0,"decimalPlaces":2}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/dead-space-fraction

Parameters

Name	Type	Required	Description
peco2	number	Yes	Mixed expired CO₂ (mmHg), collected over several breaths.
paco2	number	Yes	Arterial PaCO₂ (mmHg) from ABG — used by the Enghoff equation.
paco2Alveolar	number	No	Alveolar PACO₂ (mmHg) for the Bohr equation. Typically end-tidal CO₂ from capnography. If omitted, PaCO₂ is used as an approximation.
decimalPlaces	number	No	—

Response format

JSON result

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-dead-space-fraction": {
      "name": "dead-space-fraction",
      "description": "Calculate VD/VT using both the Bohr equation (PACO₂-based) and the Enghoff modification (PaCO₂-based). Normal ~0.20–0.40; >0.60 signals severe dead space in ARDS/PE. Derived from Bohr 1891, Enghoff 1938, Tusman 2012, LITFL, StatPearls. Not medical advice.",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=dead-space-fraction",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "dead-space-fraction",
    "arguments": {
  "peco2": 28,
  "paco2": 40,
  "paco2Alveolar": 0,
  "decimalPlaces": 2
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

Questions or issues? Contact [email protected]

Browse tools Open tool

Name

Type

Required

Description

peco2

number

Yes

Mixed expired CO₂ (mmHg), collected over several breaths.

paco2

number

Yes

Arterial PaCO₂ (mmHg) from ABG — used by the Enghoff equation.

paco2Alveolar

number

Alveolar PACO₂ (mmHg) for the Bohr equation. Typically end-tidal CO₂ from capnography. If omitted, PaCO₂ is used as an approximation.

decimalPlaces

number

—

{ "mcpServers": { "elysiatools-dead-space-fraction": { "name": "dead-space-fraction", "description": "Calculate VD/VT using both the Bohr equation (PACO₂-based) and the Enghoff modification (PaCO₂-based). Normal ~0.20–0.40; >0.60 signals severe dead space in ARDS/PE. Derived from Bohr 1891, Enghoff 1938, Tusman 2012, LITFL, StatPearls. Not medical advice.", "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=dead-space-fraction", "command": "", "args": [], "env": {}, "isActive": true, "type": "sse" } } }

{ "jsonrpc": "2.0", "id": 2, "method": "tools/call", "params": { "name": "dead-space-fraction", "arguments": { "peco2": 28, "paco2": 40, "paco2Alveolar": 0, "decimalPlaces": 2 } } }