Pecarn Head Ct Calculator

The PECARN rule exists to rule out, not to rule in. Its target condition is clinically important traumatic brain injury, defined as death from the head injury, neurosurgery, intubation for more than 24 hours, or hospital admission of two nights or more with an abnormal CT. Injuries visible on CT that need none of these were deliberately excluded, because the question is not whether a small bleed exists but whether missing it would change what happens to the child. Two age-stratified algorithms are used, since infants cannot report headache and present instead with scalp haematoma and altered behaviour. Under two years the high-risk predictors are a Glasgow Coma Scale below 15, altered mental status or palpable skull fracture, with occipital, parietal or temporal scalp haematoma, loss of consciousness of five seconds or more, severe mechanism, or a parent reporting the child is not acting normally as intermediate. At two years and above the high-risk group is GCS below 15, altered mental status or basilar skull fracture signs, with vomiting, any loss of consciousness, severe headache and severe mechanism as intermediate. Children with no predictor at all fall into a very low risk group in which the observed rate of clinically important injury was under 0.05 percent, low enough that observation without imaging is the default. The intermediate group, at roughly 0.8 to 0.9 percent, is where the rule hands the decision back to the clinician, and four to six hours of observation with serial examination resolves most of these without a scan. The rule applies only to blunt trauma presenting within 24 hours at a GCS of 14 or 15, not to penetrating injury, bleeding disorders, ventricular shunts or suspected non-accidental injury. Its justification is dose avoidance: cranial CT delivers ionising radiation to a developing brain, with estimated lifetime fatal malignancy risk on the order of one in a few thousand scans.

The Pediatric Emergency Care Applied Research Network was established in 2001 with funding from the Emergency Medical Services for Children programme of the United States Health Resources and Services Administration, as the first federally funded network able to run paediatric emergency trials at a scale no single hospital could reach. Head injury was an early priority because CT use in children had risen steeply through the 1990s while the yield of those scans remained very low, and because adult decision rules such as the Canadian CT Head Rule had no validated paediatric equivalent. Between 2004 and 2006 the network enrolled more than 42,000 children with blunt head trauma across 25 emergency departments, recording predictors prospectively on standard forms before imaging decisions were made, then splitting the cohort into derivation and validation sets. Nathan Kuppermann and colleagues published the resulting age-specific rules in The Lancet in 2009. Two other rules appeared in the same period, CHALICE from the United Kingdom in 2006 and CATCH from Canada in 2010, each optimised for a slightly different outcome. A large prospective comparison across Australia and New Zealand published in 2017 applied all three to the same patient cohort and found PECARN the most sensitive for clinically important injury, which consolidated its position in guidelines and in electronic decision support.