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Difficulty: HardNeurosurgery

A 26-year-old man is brought to the emergency department after being struck by a motor vehicle. At the scene, he had a Glasgow Coma Scale score of 13, but he became progressively somnolent during transport and was intubated by emergency medical services for airway protection. On arrival, his temperature is 36.8°C (98.2°F), blood pressure is 185/105 mm Hg, and pulse is 42/min. He is mechanically ventilated. Neurologic examination reveals an unresponsive patient. The right pupil is 8 mm and non-reactive to light, while the left pupil is 3 mm and reactive. Motor examination shows decerebrate posturing on the left side in response to painful stimuli. A large, boggy swelling is noted over the right temporal region. Extended Focused Assessment with Sonography for Trauma (eFAST) is negative. Which of the following is the most appropriate next step in management?

  1. Intravenous mannitol administrationAnswer
  2. B
    Non-contrast computed tomography of the head
  3. C
    Intravenous labetalol therapy
  4. D
    Intravenous dexamethasone administration
  5. E
    Lumbar puncture

Answer

The most appropriate next step in management is intravenous mannitol administration.
The correct answer is intravenous mannitol administration. This patient presents with the Cushing reflex (hypertension and bradycardia) and signs of right-sided uncal herniation (ipsilateral fixed, dilated pupil and contralateral decerebrate posturing), likely secondary to a traumatic epidural hematoma. In a patient who is actively herniating, the immediate priority is to lower intracranial pressure to prevent irreversible brainstem damage. Medical stabilization with hyperosmolar therapy (e.g., mannitol or hypertonic saline) must be initiated immediately before transferring the patient to the CT scanner or operating room.

Step-by-Step Solution

1
Analyze the patient's vital signs and physical exam findings in the context of trauma.
The patient exhibits hypertension and bradycardia (Cushing reflex), a fixed and dilated right pupil (right CN III compression), and left-sided decerebrate posturing (right midbrain compression).
To recognize the clinical syndrome of active right-sided uncal herniation caused by a rapidly expanding intracranial mass (likely an epidural hematoma underlying the temporal swelling).
2
Determine the physiological priority in an actively herniating patient.
Immediate reduction of intracranial pressure (ICP) is required to prevent irreversible brainstem ischemia and death.
Definitive management (craniotomy) and diagnostic confirmation (CT scan) take time; the brainstem must be protected immediately during the transition of care.
3
Select the appropriate intervention to achieve the physiological priority.
Administer an intravenous hyperosmolar agent such as mannitol.
Hyperosmolar therapy creates an osmotic gradient that rapidly draws water out of the brain parenchyma, lowering ICP and bridging the patient safely to a definitive CT scan and surgical decompression.

Key Concept

Recognition and immediate medical management of acute brain herniation in traumatic brain injury.
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Topics

Neurosurgery

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