What is the initial management for a trauma patient with a change in mental status and a negative computed tomography (CT) head scan?

Initial Management of Trauma Patient with Altered Mental Status and Negative CT Head

In a trauma patient with altered mental status and a negative head CT, you must first aggressively correct systemic causes (hypoxia, hypotension, hypoglycemia, medications), then implement serial neurological monitoring every 15 minutes for 2 hours followed by hourly assessments, while simultaneously investigating non-intracranial causes including cervical vascular injury, fat embolism, and metabolic derangements. 1, 2

Immediate Priorities: Prevent Secondary Brain Injury

The first critical step is addressing reversible systemic factors that worsen neurological outcomes:

• Maintain systolic blood pressure >110 mmHg and oxygen saturation >90%, as the combination of hypotension and hypoxemia carries a 75% mortality rate 1
• Check bedside glucose immediately, as hypoglycemia is a rapidly reversible cause of altered mental status 3
• Review and hold sedating medications, as 57.8% of patients with altered mental status are taking one or more sedating medications that confound the neurological examination 3
• Obtain arterial blood gas to assess for hypoxemia and metabolic derangements 3

Serial Neurological Monitoring Protocol

Document individual GCS components (Eye, Motor, Verbal) separately rather than just sum scores, as component profiles predict outcomes and a single GCS assessment is inadequate 4, 1

Monitoring Frequency

• Every 15 minutes for the first 2 hours 4, 1
• Hourly for the following 4-12 hours depending on risk level 1
• Document pupillary size and reactivity at each evaluation, as these are critical prognostic indicators 4, 1

Threshold for Repeat Imaging

• Any decrease of ≥2 points in GCS mandates immediate repeat CT scanning 4, 1
• Development of new focal neurological deficits or pupillary changes requires urgent repeat imaging 4, 1

Investigate Non-Intracranial Causes

A negative head CT in a trauma patient with altered mental status demands evaluation for alternative etiologies:

Cervical Vascular Injury

• CT angiography of the neck should be performed to evaluate for blunt carotid or vertebrobasilar artery injury, as these can present with delayed neurological deficits despite normal initial head CT 2
• Patients who are initially lucid and subsequently develop neurological deficits require immediate vascular imaging 2

Cervical Spine Evaluation

• CT scan of the upper cervical spine (occiput to C3) with 2mm cuts is superior to plain films and identifies 96% of upper cervical spine injuries in patients with altered mental status 5
• Plain films miss 45% of upper cervical spine injuries, including some with motor deficits 5

Fat Embolism

• Consider cerebral fat embolism in patients with long bone or pelvic fractures who develop altered mental status 24-72 hours post-injury 2
• MRI is diagnostic when fat embolism is suspected, as CT will be negative 2

Special Populations Requiring Extended Observation

Anticoagulated Patients

• Admit for 24-hour observation with repeat CT at 24 hours, even with negative initial CT, as delayed hemorrhage occurs in 1.4-4.5% of anticoagulated patients 6
• Elderly patients (≥65 years) on aspirin require longer observation, as 4% develop delayed intracranial hemorrhage 6

Patients with Subdural Hematoma

• Any documented subdural hematoma requires admission regardless of GCS, as delayed deterioration can occur even with normal neurological examination 4
• Serial GCS monitoring and repeat imaging at 24-72 hours with clinical reassessment 4

Critical Pitfalls to Avoid

• Do not administer long-acting sedatives or paralytics before completing the neurological assessment, as this masks clinical deterioration 4
• Do not assume the negative CT explains the clinical picture - if neurological status does not correlate with CT findings, pursue alternative diagnoses including vascular injury and fat embolism 2
• Do not rely on a single GCS assessment, as 13% of patients who become comatose had an initial GCS of 15 4
• Do not delay correction of hypotension, hypoxia, or hypoglycemia while pursuing additional imaging 1

Disposition Decision-Making

Safe for Discharge (All Must Be Met)

• Isolated mild TBI (GCS 15) with negative CT 7
• No anticoagulation or antiplatelet therapy 7
• No bleeding disorder or previous neurosurgical procedure 7
• Neurologically stable with normal examination 8
• Reliable follow-up and competent caregiver 7

Requires Admission

• Any patient with persistent altered mental status despite correction of systemic factors 4
• GCS 14 or fluctuating mental status 4, 1
• Anticoagulation or significant antiplatelet therapy 6
• Documented intracranial hemorrhage of any type 4, 8
• Failure to show neurological improvement within 72 hours is a negative prognostic factor requiring reassessment 4