Does intravenous (IV) lidocaine pretreatment lower intracranial pressure (ICP)?

Efficacy of IV Lidocaine for Lowering Intracranial Pressure

IV lidocaine pretreatment has limited efficacy in lowering intracranial pressure (ICP) and should not be routinely used as a standalone intervention for ICP management. While it may attenuate transient ICP spikes during airway manipulation, the evidence supporting its use is inconsistent and of low quality.

Evidence on Lidocaine for ICP Management

Prophylactic Use During Intubation/Airway Manipulation

According to the American Academy of Pediatrics guidelines, lidocaine (1-2 mg/kg IV) given 30 seconds to 5 minutes before airway instrumentation is considered an optional adjunct for rapid sequence intubation in patients with head injury/increased ICP 1. However, the guidelines specifically note that when a neuroprotective agent that reduces ICP (e.g., etomidate, thiopental) is used, lidocaine is less likely to provide additional benefit.

The evidence supporting prophylactic lidocaine use is mixed:

• A systematic review found inconsistent results regarding lidocaine's ability to attenuate ICP spikes during stimulation, with only 4 of 7 studies showing benefit 2
• No studies have demonstrated improved neurological outcomes with prophylactic lidocaine use 3

Therapeutic Use for ICP Reduction

When used therapeutically (rather than prophylactically), lidocaine may have some effect on lowering ICP:

• A systematic review found Oxford 2b, GRADE B evidence supporting ICP reduction when lidocaine is used as a therapeutic agent 2
• One study demonstrated that lidocaine (1.5 mg/kg IV) reduced ICP by approximately 15.7 torr without significantly affecting mean arterial pressure 4

However, this evidence is insufficient to recommend lidocaine as a primary intervention for ICP management.

Recommended ICP Management Approaches

For patients with elevated ICP, the following evidence-based interventions should be prioritized:

1. External ventricular drainage (EVD) - First-line surgical intervention for elevated ICP, especially with hydrocephalus 5

2. Osmotherapy:

   • Mannitol (0.25-1 g/kg IV over 20-30 minutes) 1
   • Hypertonic saline solution at a dose of 250 mOsm, infused over 15-20 minutes 1

3. Positioning - Elevate head of bed to 30° to improve venous return and reduce ICP 5

4. Cerebral perfusion pressure (CPP) management - Maintain CPP between 60-70 mmHg 1, 5

5. Avoid hypotonic solutions - Use isotonic saline solutions 5

6. Temperature control - Maintain normothermia (treat temperature >37.5°C) 5

Important Caveats and Considerations

• Avoid prolonged hypocapnia - Prolonged hypocapnia can worsen neurological outcomes by exacerbating secondary ischemic lesions 1

• Avoid 4% albumin solution in severe traumatic brain injury patients, as it has been associated with higher mortality rates 1

• Monitor ICP in patients with abnormal initial CT scan showing compressed basal cisterns, brain midline shift >5 mm, intracerebral hematoma >25 mL, or traumatic subarachnoid hemorrhage 5

• Target ICP <20 mmHg, as values 20-40 mmHg are associated with 3.95 times higher mortality risk 5

• Consider decompressive craniectomy for refractory intracranial hypertension after failure of medical management 5

Conclusion

While IV lidocaine may have some role in attenuating transient ICP spikes during airway manipulation, its effect is modest and inconsistent. For sustained ICP management, standard interventions like osmotherapy, proper positioning, EVD, and maintaining adequate cerebral perfusion pressure should be prioritized. The use of lidocaine should be limited to specific situations where other neuroprotective agents are not being used, and should not be relied upon as a primary strategy for ICP management.