Breaking the Brain Code: Elevated ICP in the ED Part 2

In Part 1 of our 2-series on Elevated ICP in the ED, Dr. Hashim Kareemi described the pathophysiology of elevated ICP and compared the options for diagnosis. Click here to review Part 1. In this Part 2 post, Dr. Kareemi takes us through a phased approach to managing and treating elevated ICP for your next emergency department shift.

Guidelines for Elevated ICP

There are a variety of management guidelines available for particular etiologies of elevated ICP, which include some considerations for patients with elevated ICP.

• Trauma: 
  • Brain Trauma Foundation – Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition (2016)
  • Seattle International Severe Traumatic Brain Injury Consensus Conference (SIBICC) – A management algorithm for patients with intracranial pressure monitoring (2019)
• Intracerebral Hemorrhage:
  • AHA/ASA – Guidelines for the Management of Spontaneous Intracerebral Hemorrhage (2015)
• Subarachnoid Hemorrhage:
  • AHA/ASA – Guidelines for the Management of Aneurysm Subarachnoid Hemorrhage (2012)
• Acute Ischemic Stroke:
  • AHA/ASA – Recommendations for the Management of Cerebral and Cerebellar Infarction with Swelling (2014)

In 2020, the Neurocritical Care Society recently published more generalized guidelines for acute treatment of cerebral edema (1), in addition to their treatment algorithm for intracranial hypertension and herniation as part of their Emergency Neurological Life Support program (2).

Unfortunately, these guidelines have limited applicability to the ED where the underlying etiology and diagnosis of elevated ICP are uncertain. Additionally, they do not provide a practical progression in care for patients in the ED and lack specific instructions.

I propose the following phased approach to treatment of patients in the ED with suspected elevated ICP. It stratifies the components of the different guidelines by the phases of care that we typically work through.

Figure 1: Phased approach to diagnosis and management of elevated intracranial pressure in the emergency department.

Maintain fundamental management (highlighted in green) instead of precipitous focus on a particular etiology (highlighted in blue), which may not yet be known. The CT scan may provide diagnostic clarity, but as we discussed it has limited diagnostic accuracy in isolation, so the onus of recognizing elevated ICP remains on the clinician using new information as the case unfolds.

The final step is “definitive management” and pertains to the ultimate disposition of the patient, whether that be an operating room, ICU, or end of life care. This must be tailored to the patient’s particular situation and informed by consulting services and the patient’s family. Much of this discussion is beyond the scope of this topic review.

The management recommendations discussed below are distilled from the previously mentioned guidelines and supplemented by expert opinion from a variety of specialties including neurocritical care, critical care, neurosurgery, and emergency medicine.

Management of Elevated ICP: Initial

Initial management involves basic resuscitation steps with consensus across guidelines and should thus be instituted for all patients with suspected elevated ICP. It is ultimately geared towards tight hemodynamic stability and preventing spikes in ICP related to pain.

Table 1: Summary of initial management steps for patient with elevated intracranial pressure.

Management of Elevated ICP: Neuroprotective Intubation

Intubation will likely be indicated for decreased level of consciousness and/or facilitation of safe transfer and imaging. As with the other initial management steps, neuroprotective intubation focuses on tight hemodynamic control while treating pain. While there is limited evidence and guidance from the management guidelines, RSI is commonly used in these scenarios and many experts agree that using these medications is safe.

Remember that despite a decreased GCS, these patients may have some degree of awareness and are likely in significant pain. A common mistake is to give smaller doses or avoid sedation altogether in patients who are unresponsive.

Table 2: Summary of neuroprotective intubation for patient with elevated intracranial pressure.

Some of the medications included above have been called into question for patients with elevated ICP. Based on the available evidence, let’s clarify three important points:

1. IV Lidocaine should NOT be used as a pre-treatment for neurologically injured patients

• The oft-quoted paper supporting this practice is a small trial of 20 patients undergoing elective neurosurgery for cerebral neoplasms (3).
• Since then, several studies and 2 subsequent systematic reviews of TBI patients undergoing RSI did not show any benefit of IV lidocaine for decreasing ICP elevation (4,5).
• Furthermore, lidocaine may not be a benign medication. While there isn’t good evidence to show harm with elevated ICP, a Cochrane review of pretreatment in mostly elective ORs showed a high odds ratio for adverse events such as bradycardia and hypotension (6).
• At best, IV lidocaine provides little to no benefit. At worst, it may contribute to hemodynamic instability. In either case, it serves to add complexity in an already high-risk situation.

2. Topical lidocaine may be a safe pre-treatment for neurologically injured patients, granted there is TIME for it to take effect and no additional risks (e.g. actively vomiting patient)

• There is limited evidence for topical lidocaine in this context. A trial assessing lidocaine instillation through an endotracheal tube prior to suctioning in patients with TBI showed mitigation in the increase in ICP with no adverse effects compared to no pre-treatment (7). While that is obviously a very different procedure than laryngoscopy, it may point to a potential benefit of topical lidocaine in blunting sympathetic response.
• Be aware that the time to maximal effect is 4-5 minutes (8).

3. Ketamine is a safe induction agent for neurologically injured patients, and does NOT appear to significantly increase ICP

• • A recent systematic review only found two small studies that showed increases in ICP, in addition to two small studies that showed decreases in ICP, with no evidence of harm in patients with acute brain injury (9).
  • Furthermore, a retrospective study of adult TBI patients undergoing RSI with either ketamine or etomidate showed no difference in mortality or patient outcomes between the two groups (10).

Management of Elevated ICP: Refractory

If the patient continues to show signs of elevated ICP, you should move on to these refractory management steps. Although the evidence behind these treatments is less clear, there is expert consensus amongst the guidelines that they can be beneficial, but their potential benefits must be balanced with their inherent risks.

Table 3: Summary of refractory management of patient with elevated intracranial pressure.

Management: Corticosteroids

Despite being used by many physicians as an empiric treatment for elevated ICP, corticosteroids are contraindicated in many of the potential underlying conditions.

I would therefore recommend against the empirical use of corticosteroids in the undifferentiated patient with elevated ICP, and only as a targeted therapy in particular etiologies such as bacterial meningitis and CNS tumors after ruling out hemorrhagic conditions with a CT scan.

Table 4: Summary of evidence for corticosteroid use in several etiologies of elevated intracranial pressure.

Take-Home Points