What is the appropriate workup for a patient with a head injury in the Emergency Department (ED)?

From the Guidelines

The initial workup for a head injury in the emergency department should include a thorough neurological examination, Glasgow Coma Scale (GCS) assessment, and appropriate imaging based on clinical presentation, with consideration of clinical decision tools such as the Canadian CT Head Rule (CCHR) or the New Orleans Criteria (NOC) to identify patients who may not require a head computed tomography (CT) scan. For patients with mild head injury (GCS 13-15), consider CT scanning if there are concerning features such as loss of consciousness, amnesia, vomiting, seizure, severe headache, age >65, anticoagulant use, or visible trauma above the clavicles, as identified by the CCHR 1. The CCHR has been shown to be highly sensitive (100%) and moderately specific (40%) for severe intracranial injury, and its use can help reduce unnecessary CT scans in low-risk patients 1.

Some key points to consider in the workup of head injury include:

• The use of clinical decision tools such as the CCHR or NOC to identify patients who may not require a head CT scan
• The importance of considering anticoagulant use, age, and other risk factors in the decision to perform imaging
• The need for serial neurological assessments to detect deterioration
• The consideration of neurosurgical consultation for significant findings like intracranial hemorrhage or skull fracture
• The potential for discharge with head injury instructions and a reliable caretaker for observation in patients with mild injuries and normal imaging

The CCHR and NOC have been compared in several studies, with the CCHR generally showing higher specificity for severe intracranial injury, although the NOC may be more sensitive 1. The NEXUS Head CT decision instrument has also been evaluated, and has been shown to have high sensitivity (100%) and moderate specificity (25%) for severe intracranial injury 1.

In patients on anticoagulants, the risk of significant intracranial injury is increased, and a lower threshold for imaging should be considered 1. Intoxicated patients may also require a lower threshold for imaging, as the presence of certain features such as headache may raise suspicion for significant injuries, although the absence of high-risk criteria cannot alone eliminate the need for CT in these patients 1.

Overall, a systematic approach to the workup of head injury, incorporating clinical decision tools and consideration of individual patient risk factors, can help identify potentially life-threatening conditions while avoiding unnecessary testing for low-risk patients, as supported by the evidence from studies such as those cited in 1 and 1.

From the Research

Head Injury Workup in the ED

• The management of head-injured patients in the emergency department (ED) is not standardized, but studies have proposed practical protocols to avoid overuse of radiologic examinations and identify patients with possible life-threatening complications 2.
• A study from 1997 divided patients into four groups based on clinical parameters and risk factors, and proposed a protocol for each group, including the use of computed tomography (CT) scans and observation periods 2.
• Another study from 2019 assessed adherence to National Institute for Health and Care Excellence (NICE) computed tomography (CT) head guidelines at a teaching hospital in the United Kingdom, and found that adherence was inadequate but could be improved with interventions 3.

Assessment of Geriatric Patients with Head Injury

• A study from 2021 developed and implemented a novel level III trauma protocol (L3TP) to better evaluate and diagnose intracranial injury in elderly patients presenting with minor head trauma after a fall 4.
• The L3TP requires immediate assessment of high-risk patients, including those taking anticoagulant or antiplatelet agents, and determines the need for emergent imaging, obviating the need for trauma team activation unless an intracranial hemorrhage (ICH) is found 4.

Noninvasive Assessment of Intracranial Pressure

• A study from 2016 described a modified technique of measuring the diameters of the optic nerve sheath (ONSD) for assessment of intracranial pressure (ICP) in patients with intracerebral or subarachnoid hemorrhage (SAH) 5.
• Another study from 2023 validated the use of optic nerve diameter measurements on CT as a screening tool for intracranial hypertension in a large cohort of brain-injured patients, and found that CT-derived optic nerve diameter was sensitive but not specific for intracranial hypertension 6.

Key Findings

• The use of CT scans and observation periods can help identify patients with possible life-threatening complications and avoid overuse of radiologic examinations 2.
• Adherence to NICE guidelines for head injury can be improved with interventions 3.
• The L3TP can quickly identify ICH in elderly patients without activating the trauma team for every elderly patient presenting to the ED with a potential head injury after a fall 4.
• ONSD measurements can be used to assess intracranial pressure in patients with intracerebral or subarachnoid hemorrhage (SAH) 5.
• CT-derived optic nerve diameter can be used as a screening tool for intracranial hypertension, but its sensitivity and specificity vary 6.