Risks of intracranial haematoma in head injured adults.

A study was conducted to estimate the risk that an adult (age 15 or over) will develop a surgically significant intracranial haematoma after a head injury. Two simple features were used that can be recognised by clinicians with minimal training: a skull fracture and the conscious level. The risks were calculated from samples of 545 patients with haematomas, 2773 head injured patients in accident and emergency departments, and 2783 head injured patients in primary surgical wards. With radiological evidence of skull fracture and any impairment of consciousness (including disorientation) one patient in four in an accident and emergency department or primary surgical ward will develop a haematoma. With no skull fracture and preserved orientation the risk to a patient in an accident and emergency department is one in 6000. The use of risk levels as a basis for decision making about head injured patients may result in fewer haematomas being detected too late and savings of resources by reducing the admission and investigation of low risk categories of patients.