{"uid":"cap_xShTGqRISMpGse795wQjb","slug":"nexus-c-spine-rule-calculator-a5c101ae","name":"NEXUS C-Spine Rule Calculator","description":"NEXUS C-spine rule (Hoffman 2000). The patient is NEXUS low-risk, and imaging is not indicated by this rule, only when all five hold: no posterior midline cervical-spine tenderness, no focal neurologic deficit, normal alertness, no intoxication, and no painful distracting injury. Any failed criterion means x-ray is indicated. Not a diagnosis, not the Canadian C-spine rule, and not NEXUS chest. Blunt-trauma adults as published. magent does not examine the patient.","url":"https://api.magentlab.com/api/calc/nexus","method":"GET","headers":{},"bodySchema":{"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":["midline_cervical_tenderness","focal_neuro_deficit","normal_alertness","intoxication","distracting_injury"],"properties":{"intoxication":{"type":"boolean","description":"Intoxication. true means intoxicated and the low-risk criterion fails. true or false as assigned by the caller."},"normal_alertness":{"type":"boolean","description":"Normal alertness. true means alertness is normal and the low-risk criterion holds; false is altered alertness and the criterion fails."},"distracting_injury":{"type":"boolean","description":"Painful, distracting injury. true means a distracting injury is present and the low-risk criterion fails. true or false as assigned by the caller."},"focal_neuro_deficit":{"type":"boolean","description":"Focal neurologic deficit. true means a deficit is present and the low-risk criterion fails. true or false as assigned by the caller."},"midline_cervical_tenderness":{"type":"boolean","description":"Posterior midline cervical-spine tenderness. true means tenderness is present and the low-risk criterion fails. true or false as assigned by the caller."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"path":"/api/calc/nexus","count":2,"items":[{"formula":"nexus","citation":{"id":"hoffman-2000","doi":"10.1056/NEJM200007133430203","title":"Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma","source":"N Engl J Med. 2000;343(2):94-99","authors":"Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI; National Emergency X-Radiography Utilization Study Group"},"criteria":[{"met":true,"factor":"no_midline_cervical_tenderness"},{"met":true,"factor":"no_focal_neuro_deficit"},{"met":true,"factor":"normal_alertness"},{"met":true,"factor":"no_intoxication"},{"met":true,"factor":"no_distracting_injury"}],"disclaimer":"Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.","nexus_low_risk":true,"xray_indicated":false,"formula_expression":"NEXUS low-risk iff no posterior midline cervical-spine tenderness and no focal neurologic deficit and normal alertness and no intoxication and no painful distracting injury"},{"formula":"nexus","citation":{"id":"hoffman-2000","doi":"10.1056/NEJM200007133430203","title":"Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma","source":"N Engl J Med. 2000;343(2):94-99","authors":"Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI; National Emergency X-Radiography Utilization Study Group"},"criteria":[{"met":true,"factor":"no_midline_cervical_tenderness"},{"met":true,"factor":"no_focal_neuro_deficit"},{"met":true,"factor":"normal_alertness"},{"met":true,"factor":"no_intoxication"},{"met":true,"factor":"no_distracting_injury"}],"disclaimer":"Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.","nexus_low_risk":true,"xray_indicated":false,"formula_expression":"NEXUS low-risk iff no posterior midline cervical-spine tenderness and no focal neurologic deficit and normal alertness and no intoxication and no painful distracting injury"}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_rcTMNj7qB9MvX-zbdbjAk","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Evaluates the five NEXUS low-risk criteria to determine whether cervical-spine imaging is indicated after blunt trauma in adults","exampleAgentPrompt":"My blunt trauma patient has no posterior midline cervical tenderness, no focal neuro deficit, is alert and not intoxicated, but does have a distracting painful leg fracture — do they need a c-spine x-ray per the NEXUS rule?","exampleUseCases":[{"title":"ED triage cervical clearance decision","prompt":"Patient came in after a car accident — no midline cervical tenderness, no neurologic deficits, fully alert, not intoxicated, but has a painful rib fracture. Does the NEXUS rule say we need to image the c-spine?"},{"title":"Rule out imaging for low-risk trauma","prompt":"I have a blunt trauma patient who is alert, sober, has no posterior midline neck tenderness, no focal neuro deficits, and no distracting injuries — run the NEXUS criteria and tell me if x-ray is indicated."},{"title":"Intoxicated trauma patient imaging decision","prompt":"Patient was in a bar fight, has blunt neck trauma, appears intoxicated — no midline tenderness, no neuro deficits, alert otherwise, no distracting injuries. What does the NEXUS rule say about cervical imaging?"}],"resultDescription":"A structured determination of whether the patient meets NEXUS low-risk criteria — specifically whether all five criteria hold (making imaging not indicated) or whether any criterion fails (making imaging indicated), along with the pass/fail status of each individual criterion.","failureModes":["Missing any of the five required boolean query parameters returns a validation error","Incorrect boolean types (e.g. strings instead of true/false) will cause schema rejection","Result is rule-based only — does not account for Canadian C-Spine Rule or NEXUS chest criteria","Not valid for pediatric patients or non-blunt trauma mechanisms"],"whenToPreferThis":"Use this endpoint when you need to apply the validated Hoffman 2000 NEXUS criteria specifically for cervical spine imaging decisions in adult blunt trauma patients. Prefer this over the Canadian C-Spine Rule when the patient population matches the original NEXUS publication (e.g. any alertness level, any age adult). Do not use for chest imaging decisions, penetrating trauma, or pediatric patients.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:17:15.503Z","isFirstParty":false}