Health
Urea Reduction Ratio (URR) — Dialysis Adequacy
Calculate the Urea Reduction Ratio (URR) for a single hemodialysis session: URR (%) = (Pre-BUN − Post-BUN) / Pre-BUN × 100. KDOQI recommends a minimum URR ≥65% and a target dose ≥70%. URR is a simple adequacy marker but is being phased out in favor of Kt/V, which also accounts for urea generation and volume contraction. Derived from the KDOQI Clinical Practice Guideline for Hemodialysis Adequacy. Valid for single hemodialysis sessions with BUN drawn pre- and immediately post-treatment; not for peritoneal dialysis. Not medical advice.
Quick start
Call this tool from your code in three languages.
curl -X POST 'https://api.elysiatools.com/en/api/tools/urea-reduction-ratio' \
-H 'Content-Type: application/json' \
-d '{"preBun":90,"postBun":27,"decimalPlaces":4}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
POST https://api.elysiatools.com/en/api/tools/urea-reduction-ratioParameters
| Name | Type | Required | Description |
|---|---|---|---|
| preBun | number | Yes | Pre-dialysis blood urea nitrogen in mg/dL. Must be positive. |
| postBun | number | Yes | Post-dialysis blood urea nitrogen in mg/dL. Must be ≥0 and less than pre-BUN. |
| decimalPlaces | number | No | — |
Response format
JSON result
{
"key": {...},
"metadata": {
"key": "value"
},
"error": "Error message (optional)",
"message": "Notification message (optional)"
}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:
{
"mcpServers": {
"elysiatools-urea-reduction-ratio": {
"name": "urea-reduction-ratio",
"description": "Calculate the Urea Reduction Ratio (URR) for a single hemodialysis session: URR (%) = (Pre-BUN − Post-BUN) / Pre-BUN × 100. KDOQI recommends a minimum URR ≥65% and a target dose ≥70%. URR is a simple adequacy marker but is being phased out in favor of Kt/V, which also accounts for urea generation and volume contraction. Derived from the KDOQI Clinical Practice Guideline for Hemodialysis Adequacy. Valid for single hemodialysis sessions with BUN drawn pre- and immediately post-treatment; not for peritoneal dialysis. Not medical advice.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=urea-reduction-ratio",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "urea-reduction-ratio",
"arguments": {
"preBun": 90,
"postBun": 27,
"decimalPlaces": 4
}
}
}