This version was machine-translated from German and has not been medically reviewed. The authoritative version is the German version.

CATCH & CATCH2 Head Injury Rule

Canadian CT rule for mild traumatic brain injury: four high-risk and three (CATCH2: four) medium-risk factors

High-risk factors (neurointervention)

GCS not 15 within 2 hours of the injury

Suspected open or depressed skull fracture

increasing headache

Irritability on examination

Intermediate-risk factors (brain injury on CT)

large, doughy cephalohematoma

Signs of a skull base fracture

dangerous mechanism (road traffic accident, fall ≥ 0.9 m or 5 stairs, fall from a bicycle without helmet)

≥ 4 episodes of vomiting (CATCH2)

Calculation aid for healthcare professionals: the calculator reproduces what the sources cited assign to the inputs. Clinical assessment and every treatment decision remain with the treating physician. Inputs and results are not stored.

Frequently asked questions

CATCH & CATCH2 Head Injury Rule: What does this calculator compute?

CATCH (Osmond 2010) and CATCH2 (2018) for children with minor head trauma (GCS 13–15) and loss of consciousness, amnesia, disorientation, persistent vomiting or irritability: high-risk factors (neurological intervention) and medium-risk factors (brain injury on CT), CATCH2 additionally ≥ 4 episodes of vomiting.

CATCH & CATCH2 Head Injury Rule: Which sources is this calculator based on?

Osmond MH, Klassen TP, Wells GA, et al.; Pediatric Emergency Research Canada (PERC) Head Injury Study Group: CATCH: a clinical decision rule for the use of computed tomography in children with minor head injury (CMAJ 182:341–348) (2010); Osmond MH, Klassen TP, Wells GA, et al.: Validation and refinement of a clinical decision rule for the use of computed tomography in children with minor head injury in the emergency department (CMAJ 190:E816–E822) – CATCH2 (2018)