# PECARN Pediatric C-Spine Risk Stratifier (Leonard 2024)

> PECARN Pediatric C-Spine Risk Stratifier (Leonard 2024) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Stratifies pediatric cervical spine injury risk into high, intermediate, or low categories based on Leonard 2024 CART decision tree, guiding CT, x-ray, or clinical clearance decisions.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/pecarn_cspine
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pecarn-pediatric-c-spine-risk-stratifier-leonard-2024-1bda0f0d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Y1JnZIuoUVT12ab-Orn12

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability pecarn-pediatric-c-spine-risk-stratifier-leonard-2024-1bda0f0d
```

Example prompt: I have a pediatric trauma patient with neck pain and midline tenderness but no GCS depression, no airway issues, no focal deficits, no AMS, no substantial head or torso injury — run the PECARN C-spine Leonard 2024 rule and tell me what imaging is recommended.

## When to prefer this

Use this endpoint when you need a structured, rule-based pediatric C-spine imaging decision aligned with the Leonard 2024 CART algorithm without an age split. Prefer over NEXUS or Canadian C-Spine Rule when dealing exclusively with pediatric patients. Choose over PECARN head or PECARN IAI tools when the clinical question is cervical spine injury, not intracranial or intra-abdominal injury.

## Known failure modes

- Missing required boolean parameters returns a validation error
- All parameters must be explicitly provided as true/false — null or missing fields are not inferred
- Intermediate risk is only returned when no high-risk factor is present; misclassification of inputs by caller can yield incorrect tier
- Endpoint does not validate clinical plausibility of contradictory inputs

## How this service works

PECARN pediatric C-spine (Leonard 2024). No age split. High (consider CT) if GCS 3-8 or AVPU U; abnormal airway, breathing, or circulation; or focal neurologic deficit. Else intermediate (consider x-rays) if neck pain; AMS GCS 9-14; substantial head or torso injury; or midline neck tenderness. Else low (consider clinical clearance). High-risk beats intermediate. Not NEXUS, Canadian C-spine, PECARN head, or PECARN IAI. Not a medical device. magent does not examine the patient.

## Output

Returns a risk tier (high, intermediate, or low) with the corresponding imaging recommendation: CT for high-risk, x-rays for intermediate-risk, or clinical clearance for low-risk. Includes the decision logic indicating which input flags drove the classification, consistent with the Leonard 2024 CART algorithm.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "gcs_3_to_8_or_avpu_u",
      "abnormal_airway_breathing_or_circulation",
      "focal_neurologic_deficit",
      "neck_pain",
      "altered_mental_status_gcs_9_to_14",
      "substantial_head_injury",
      "substantial_torso_injury",
      "midline_neck_tenderness"
     ],
     "properties": {
      "neck_pain": {
       "type": "boolean",
       "description": "Self-reported neck pain as assigned by the caller (Leonard 2024 CART non-negligible / intermediate). true or false. Consider x-rays when any intermediate factor is true and no high-risk factor is true. magent does not take a pain score."
      },
      "gcs_3_to_8_or_avpu_u": {
       "type": "boolean",
       "description": "GCS 3-8 or AVPU = U as assigned by the caller (Leonard 2024 high-risk; paper: factors associated with >10% CSI). true or false. High-risk; consider CT when any high-risk factor is true. This is not the intermediate GCS 9-14 / AVPU V or P / other AMS flag. magent does not take a GCS integer or AVPU letter."
      },
      "midline_neck_tenderness": {
       "type": "boolean",
       "description": "Midline neck tenderness as assigned by the caller (Leonard 2024 CART non-negligible / intermediate). true or false. magent does not palpate the neck."
      },
      "substantial_head_injury": {
       "type": "boolean",
       "description": "Substantial head injury as assigned by the caller (Leonard 2024 CART non-negligible / intermediate). Paper: injuries warranting inpatient observation or surgical intervention (example: skull fracture). true or false. Caller assigns the boolean; magent does not interpret imaging."
      },
      "focal_neurologic_deficit": {
       "type": "boolean",
       "description": "Focal neurologic deficit (paresthesia, numbness, or weakness) as assigned by the caller (Leonard 2024 high-risk). true or false. High-risk; consider CT when any high-risk factor is true. magent does not e
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pecarn-pediatric-c-spine-risk-stratifier-leonard-2024-1bda0f0d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)