Editorial

Minor head injury: A proposed strategy for emergency management

The aim of diagnostic imaging for maxillofacial trauma is to provide additional information that can positively influence medical or surgical patient management. Current advances in diagnostic imaging have come from the confluence of 3 driving forces: (1) the demand from clinicians to enhance and expand their diagnostic abilities; (2) the development of new theoretical concepts by basic scientists; and (3) the application of concepts by engineers and manufacturers to provide increasingly sophisticated imaging capabilities. The role of imaging within the health care environment is, however, also buffeted by the complex, sometimes competing, interactions of external social, political, economic, and technological pressures at the national, regional, and local levels. The purposes of this review are to provide a perspective on current imaging modalities used for maxillofacial trauma and to provide an insight into the influences, both technologic and external, on future developments and applications.

The study objectives were to ascertain historical and clinical criteria differentiating intracranial injury (ICI) in elderly patients with minor head trauma (MHT), and determine applicability of current head computed tomography (CT) scan indications in this population. A 12-month retrospective chart review was performed at a community teaching hospital with 34,000 annual Emergency Department (ED) visits. Included were patients ≥ 65 years old sustaining MHT with a Glasgow Coma Scale (GCS) score of 13–15 who had a CT scan performed during their hospital stay. Data included: injury mechanism, symptoms, signs, GCS, anticoagulation use or studies, presence of alcohol or drug, CT scan result, diagnosis, and outcome and intervention(s). There were 133 patients, with 19 (14.3%) suffering ICI. Four ICI patients required neurosurgical intervention. The mean age was 80.4 years and 66% were female. Four of 19 ICI patients (21%) had a GCS of 15, no neurologic symptoms, alcohol use or anticoagulation. Only 1 of 13 signs and symptoms correlated with ICI. In this study, no useful clinical predictors of intracranial injury in elderly patients with MHT were found. Current protocols based on clinical findings may miss 30% of elderly ICI patients. Head CT scan is recommended on all elderly patients with MHT.

There is much controversy about the use of computed tomography (CT) for patients with minor head injury. We aimed to develop a highly sensitive clinical decision rule for use of CT 2in patients with minor head injuries.

We carried out this prospective cohort study in the emergency departments of ten large Canadian hospitals and included consecutive adults who presented with a Glasgow Coma Scale (GCS) score of 13–15 after head injury. We did standardised clinical assessments before the CT scan. The main outcome measures were need for neurological intervention and clinically important brain injury on CT.

The 3121 patients had the following characteristics: mean age 38·7 years); GCS scores of 13 (3·5%), 14 (16·7%), 15 (79·8%); 8% had clinically important brain injury; and 1% required neurological intervention. We derived a CT head rule which consists of five high-risk factors (failure to reach GCS of 15 within 2 h, suspected open skull fracture, any sign of basal skull fracture, vomiting ≥2 episodes, or age ≥65 years) and two additional medium-risk factors (amnesia before impact >30 min and dangerous mechanism of injury). The high-risk factors were 100% sensitive (95% CI 92–100%) for predicting need for neurological intervention, and would require only 32% of patients to hundergo CT. The medium-risk factors were 98·4% sensitive (95% CI 96–99%) and 49·6% specific for predicting clinically important brain injury, and would require only 54% of patients to undergo CT.

We have developed the Canadian CT Head Rule, a highly sensitive decision rule for use of CT. This rule has the potential to significantly standardise and improve the emergency management of patients with minor head injury.

Head injuries are among the most common types of trauma seen in North American emergency departments, with an estimated 1 million cases seen annually. “Minor” head injury (sometimes known as “mild”) is defined by a history of loss of consciousness, amnesia, or disorientation in a patient who is conscious and talking, that is, with a Glasgow Coma Scale score of 13 to 15. Although most patients with minor head injury can be discharged without sequelae after a period of observation, in a small proportion, their neurologic condition deteriorates and requires neurosurgical intervention for intracranial hematoma. The objective of the Canadian CT Head Rule Study is to develop an accurate and reliable decision rule for the use of computed tomography (CT) in patients with minor head injury. Such a decision rule would allow physicians to be more selective in their use of CT without compromising care of patients with minor head injury. This paper describes in detail the rationale, objectives, and methodology for Phase I of the study in which the decision rule was derived. [Stiell IG, Lesiuk H, Wells GA, McKnight RD, Brison R, Clement C, Eisenhauer MA, Greenberg GH, MacPhail I, Reardon M, Worthington J, Verbeek R, Rowe B, Cass D, Dreyer J, Holroyd B, Morrison L, Schull M, Laupacis A, for the Canadian CT Head and C-Spine Study Group. The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. August 2001;38:160-169.]

The use of short-term observation in evaluating and treating injured patients is not a new concept. Reports of the use of emergency department observation units (EDOUs) for the management of trauma patients first occurred during the 1980s.3, 17, 30, 43 Most of these studies were conducted in large urban trauma facilities, but one report of an EDOU that managed trauma patients did come form a community hospital.³⁰ Recently there has been a push for the development of EDOUs in large medical centers and community hospitals, and certain injured patients may be appropriately managed in these units.

Much of the recent trauma literature has focused on reducing the cost and admissions associated with caring for trauma patients. It has been suggested that from 1984 to 1986 an estimated 52% of trauma care expenditure went to patients with minor injury.⁵⁴ Reimbursement for trauma patients admitted to the hospital and subsequently found to have minor injuries does not cover the true cost of the care provided.³⁴ Short-term observation and treatment of some of these patients may be one method through which hospitals can continue to provide quality care in a more efficient and cost-effective manner. Emergency department observation units may be particularly well suited to this patient population. This article focuses on the use of an EDOU in the treatment of patients with blunt and penetrating abdominal and chest injuries, and head injuries. Many other types of injuries may be evaluated in these units (i.e., pregnant patients, bone injuries, soft tissue injuries), but these will be mentioned only briefly.

Data from the Head Injury Task Force, National Institute of Neurologic Disorders and Strokes, estimate that there are 2,000,000 cases of traumatic brain injury (TBI) in the United States per year, with approximately 500,000 patients requiring hospitalization. About 100,000 Americans die as a result of this brain injury, with most of these deaths occurring within several hours from the time of the accident. Of the survivors, 70,000 to 90,000 will experience some sort of lifetime debilitation, and 2000 will live in a persistent vegetative state. The economic cost of TBI in the United States is estimated to exceed $25 billion annually.

There has been considerable emphasis on elucidating the pathophysiology of brain injury, and determining management strategies for patients with moderate and severe head trauma. ²⁵ Significant controversy continues regarding the best strategy for patients with mild head injury, particularly because of concerns that these patients may harbor an intracranial lesion that requires neurosurgic intervention. In addition, because of the large numbers of patients with mild TBI, the social and economic consequences of patients with disabling symptoms cannot be ignored. Because most patients with mild TBI present to the emergency department (ED), it is important that ED physicians have clear direction on how to proceed in their evaluation. This article reviews the prevalence of mild head injury, the pathophysiology, and discusses the indications for cranial CT scanning.