What is the immediate management for a patient with diffuse axonal injury?

Immediate Management of Diffuse Axonal Injury

Perform non-contrast CT head immediately as the mandatory first-line imaging, then focus on preventing secondary brain injury through aggressive physiological optimization including maintaining systolic blood pressure >110 mmHg, controlled ventilation with avoidance of hypocapnia, and ICP monitoring in severe cases. 1, 2

Initial Diagnostic Approach

• Obtain non-contrast CT (NCCT) of the head without delay as the first-line imaging modality in acute moderate to severe traumatic brain injury (class I recommendation). 3, 1, 2

• Recognize that NCCT has significant limitations—it detects only 10% of DAI cases because >80% of axonal lesions lack macroscopic hemorrhage. 3

• Proceed to MRI when CT is normal but unexplained neurologic findings persist (class I recommendation), though this typically occurs after initial stabilization rather than in the immediate phase. 3, 1

• Use T2*-weighted gradient-echo (GRE), susceptibility-weighted imaging (SWI), and diffusion-weighted imaging (DWI) as the optimal MRI sequences for detecting microhemorrhages and axonal injury. 1, 2

Immediate Physiological Management

Blood Pressure Control

• Maintain systolic blood pressure >110 mmHg to ensure adequate cerebral perfusion pressure and prevent secondary ischemic injury. 1

• Avoid hypotension aggressively, as it is a critical determinant of outcome in traumatic brain injury. 1

Airway and Ventilation Management

• Intubate and mechanically ventilate patients with severe DAI to control ventilation and protect the airway. 1

• Monitor end-tidal CO2 continuously and prevent hypocapnia, which causes cerebral vasoconstriction and increases the risk of brain ischemia. 1

• Target normocapnia rather than prophylactic hyperventilation, as the latter can worsen outcomes. 1

Intracranial Pressure Monitoring

• Insert ICP monitoring in patients with severe traumatic brain injury (GCS ≤8) with signs of high ICP on brain CT scan to detect intracranial hypertension. 3, 1

• Treat intracranial hypertension when ICP exceeds 20 mmHg threshold. 1

• Consider external ventricular drain placement for both monitoring and therapeutic CSF drainage in refractory cases. 3

Sedation and Analgesia

• Provide adequate sedation and analgesia to control ICP and prevent agitation, though no single agent has proven superior. 3

• Monitor for arterial hypotension with barbiturates, midazolam boluses, or opioid boluses, and adjust accordingly. 3

Neurosurgical Considerations

• Consult neurosurgery immediately for evaluation of mass lesions requiring surgical intervention, though DAI itself has no specific surgical treatment. 3, 1

• Consider decompressive craniectomy only for refractory intracranial hypertension in multidisciplinary discussion, recognizing that while it reduces mortality, it may increase the proportion of patients with poor neurological outcomes. 3

Early Rehabilitation Planning

• Initiate early physical therapy to prevent joint contractures and muscle atrophy, including proper positioning, frequent repositioning, range of motion exercises, and splinting. 1

• Recognize that DAI requires long-term hospitalization and rehabilitation, with survivors needing extended recovery periods. 4

Critical Pitfalls to Avoid

• Do not rely on initial CT alone to rule out DAI—approximately 27% of patients with mild TBI and normal CT have MRI abnormalities. 3

• Do not assume the number of microhemorrhages predicts outcome—while helpful for diagnosis, lesion count does not reliably correlate with injury severity or outcomes. 3, 2

• Do not perform routine repeat imaging without clinical indication—follow-up imaging is indicated only with neurological deterioration, not on a routine schedule. 3, 1

• Avoid delayed recognition—DAI can present with delayed neurological deterioration even when initial symptoms are minimal. 5

Prognostic Communication

• Establish multidisciplinary case review early for patients with severe DAI and communicate with regional neuroscience centers. 1

• Recognize that Grade III DAI (dorsolateral brainstem lesions) carries the highest mortality, and the presence of >4 foci of hemorrhagic axonal injury on MRI is an independent predictor of poor outcome. 2, 4

• Initiate honest discussions about prognosis at admission, establishing patient values and preferences early to guide care planning. 1