{"uid":"cap_pzFWiXfjQ-Ak8GqWC0MEA","slug":"pecarn-pediatric-head-ct-decision-rule-kuppermann-2009-ccc9ff27","name":"PECARN Pediatric Head CT Decision Rule (Kuppermann 2009)","description":"PECARN pediatric head CT (Kuppermann 2009). Two age trees (under 2 vs 2-17). High if any age-applicable high-risk factor (GCS <=14 or altered mental status in both; palpable skull fracture if under 2; signs of basilar skull fracture if 2 or older), else intermediate if any age-applicable intermediate factor, else low. CT recommended only when high. Not a diagnosis. Not Canadian CT Head, CATCH, CHALICE, NEXUS, or PECARN IAI/febrile/c-spine. magent does not examine the patient.","url":"https://api.magentlab.com/api/calc/pecarn_head","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":["age","gcs_le_14","altered_mental_status","palpable_skull_fracture","signs_basilar_skull_fracture","nonfrontal_scalp_hematoma","loc_ge_5_seconds","not_acting_normally","history_of_loc","history_of_vomiting","severe_headache","severe_mechanism"],"properties":{"age":{"type":"integer","description":"Age in years (0-17). Age 0 and 1 use the lt_2 tree; age 2 through 17 use the ge_2 tree. Age 18 is rejected."},"gcs_le_14":{"type":"boolean","description":"GCS <=14 as assigned by the caller. true or false. High-risk in both trees. GCS 15 is not <=14. magent does not take a GCS integer."},"history_of_loc":{"type":"boolean","description":"History of loss of consciousness as assigned by the caller. true or false. Intermediate only on the ge_2 tree; parsed but not scored when age < 2."},"severe_headache":{"type":"boolean","description":"Severe headache as assigned by the caller. true or false. Intermediate only on the ge_2 tree; parsed but not scored when age < 2."},"loc_ge_5_seconds":{"type":"boolean","description":"Loss of consciousness >=5 seconds as assigned by the caller. true or false. Intermediate only on the lt_2 tree; parsed but not scored when age >= 2."},"severe_mechanism":{"type":"boolean","description":"Severe mechanism as assigned by the caller. true or false. Intermediate in both trees. Paper list: MVC ejection/rollover/death of another passenger; unhelmeted pedestrian or bicyclist struck by a motorized vehicle; fall >3 ft if <2 years or >5 ft if >=2 years; head struck by a high-impact object. magent does not classify mechanism or take fall height."},"history_of_vomiting":{"type":"boolean","description":"History of vomiting as assigned by the caller. true or false. Intermediate only on the ge_2 tree; parsed but not scored when age < 2."},"not_acting_normally":{"type":"boolean","description":"Not acting normally per parent report as assigned by the caller. true or false. Intermediate only on the lt_2 tree; parsed but not scored when age >= 2."},"altered_mental_status":{"type":"boolean","description":"Altered mental status as assigned by the caller (paper: agitation, somnolence, repetitive questioning, or slow response). true or false. High-risk in both trees."},"palpable_skull_fracture":{"type":"boolean","description":"Palpable skull fracture as assigned by the caller. true or false. High-risk only on the lt_2 tree; parsed but not scored when age >= 2."},"nonfrontal_scalp_hematoma":{"type":"boolean","description":"Occipital, parietal, or temporal scalp hematoma (not frontal) as assigned by the caller. true or false. Intermediate only on the lt_2 tree; parsed but not scored when age >= 2."},"signs_basilar_skull_fracture":{"type":"boolean","description":"Signs of basilar skull fracture as assigned by the caller. true or false. High-risk only on the ge_2 tree; parsed but not scored when age < 2."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"path":"/api/calc/pecarn_head","count":2,"items":[{"formula":"pecarn_head","age_band":"ge_2","citation":{"id":"kuppermann-2009","doi":"10.1016/S0140-6736(09)61558-0","title":"Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study","source":"Lancet. 2009;374(9696):1160-1170","authors":"Kuppermann N, Holmes JF, Dayan PS, et al."},"criteria":[{"met":false,"factor":"gcs_le_14"},{"met":false,"factor":"altered_mental_status"},{"met":false,"factor":"signs_basilar_skull_fracture"},{"met":false,"factor":"history_of_loc"},{"met":false,"factor":"history_of_vomiting"},{"met":false,"factor":"severe_headache"},{"met":false,"factor":"severe_mechanism"}],"age_years":10,"risk_tier":"low","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.","ct_recommended":false,"observation_vs_ct":false,"ct_not_recommended":true,"formula_expression":"high if any age-applicable high-risk factor, else intermediate if any age-applicable intermediate factor, else low; lt_2 tree if age < 2, ge_2 tree if age 2-17"},{"formula":"pecarn_head","age_band":"ge_2","citation":{"id":"kuppermann-2009","doi":"10.1016/S0140-6736(09)61558-0","title":"Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study","source":"Lancet. 2009;374(9696):1160-1170","authors":"Kuppermann N, Holmes JF, Dayan PS, et al."},"criteria":[{"met":false,"factor":"gcs_le_14"},{"met":false,"factor":"altered_mental_status"},{"met":false,"factor":"signs_basilar_skull_fracture"},{"met":false,"factor":"history_of_loc"},{"met":false,"factor":"history_of_vomiting"},{"met":false,"factor":"severe_headache"},{"met":false,"factor":"severe_mechanism"}],"age_years":10,"risk_tier":"low","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.","ct_recommended":false,"observation_vs_ct":false,"ct_not_recommended":true,"formula_expression":"high if any age-applicable high-risk factor, else intermediate if any age-applicable intermediate factor, else low; lt_2 tree if age < 2, ge_2 tree if age 2-17"}]}},"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_6PUUpa3OxedEXiDWVS_mw","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":"Applies the PECARN pediatric head CT decision rule to classify children (age 0-17) as high, intermediate, or low risk for clinically important traumatic brain injury, recommending CT only for high-risk cases.","exampleAgentPrompt":"Run the PECARN head CT rule for a 6-year-old who fell more than 5 feet: GCS is 15 so gcs_le_14 is false, no altered mental status, no basilar skull fracture signs, no history of vomiting, no severe headache, no loss of consciousness, but severe mechanism is true and history of LOC is false.","exampleUseCases":[{"title":"Toddler fall from height triage","prompt":"Apply the PECARN pediatric head CT rule to an 18-month-old who fell off a changing table: GCS is fine so gcs_le_14 is false, altered mental status is false, palpable skull fracture is true, nonfrontal scalp hematoma is false, loss of consciousness under 5 seconds so loc_ge_5_seconds is false, not acting normally is false, severe mechanism is true. What's the risk level and should we get a CT?"},{"title":"School-age cyclist hit by car","prompt":"A 9-year-old unhelmeted cyclist was struck by a car — that's a severe mechanism. GCS is 15 so gcs_le_14 is false, altered mental status is false, no basilar skull fracture signs, history of vomiting is true, severe headache is false, history of LOC is false. Run PECARN to tell me if a head CT is recommended."},{"title":"Teenager with altered mental status after MVC","prompt":"Can you run the PECARN head CT decision rule for a 14-year-old involved in a motor vehicle collision with ejection? GCS is 13 so gcs_le_14 is true, altered mental status is true, signs of basilar skull fracture are false, history of vomiting is false, severe headache is true, history of LOC is true, severe mechanism is true. What's the risk classification?"}],"resultDescription":"Returns a risk stratum (high, intermediate, or low), a CT recommendation (CT recommended only if high risk), the age-appropriate decision tree applied (lt_2 for ages 0-1, ge_2 for ages 2-17), and the specific risk factors that drove the classification. Not a clinical diagnosis; intended as decision support only.","failureModes":["Age 18 or above is rejected with a validation error — only ages 0-17 are accepted","Missing required boolean query parameters return a schema validation error","Ambiguous or non-boolean values for clinical flags cause parameter rejection","Conflicting clinical inputs (e.g. GCS <=14 flagged false but altered mental status true) are accepted as-is since magent does not validate clinical coherence","Network or payment failure (402 if x402 payment not attached) returns an HTTP 402 error"],"whenToPreferThis":"Use this endpoint when you need to apply the validated PECARN Kuppermann 2009 pediatric head CT rule specifically — for patients aged 0-17 with blunt head trauma where you need age-stratified (under 2 vs 2-17) CT decision support. Prefer this over generic clinical calculators when the decision rule must be traceable to a specific published algorithm. Do not use for adults, for Canadian CT Head / CATCH / CHALICE / NEXUS rules, or for PECARN intra-abdominal injury, febrile illness, or cervical spine variants.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:01:19.689Z","isFirstParty":false}