3 Intracranial Pressure and Neurological Deterioration

Interpreting ICP trends

Intracranial pressure (ICP) readings should be interpreted alongside the patient’s neurological examination and the direction of change over time. In adults with severe traumatic brain injury, the Brain Trauma Foundation recommends treatment when ICP is above $22\ \text{mm Hg}$. A single value should not be considered in isolation; the trend, its duration, and the patient’s clinical picture matter.

Compare neurological findings with baseline

Compare each neurological examination with the patient’s baseline and with prior examinations. A decline matters even before a particular score or threshold is reached; use the same assessment approach when comparing serial examinations.

A change in mental status can be an early warning sign. Increasing restlessness, agitation, or confusion may precede more severe signs. A patient who becomes harder to arouse, opens their eyes only to pain instead of voice, or stops following commands and instead withdraws from pain has worsened from an examination in which they opened their eyes to voice and obeyed commands.

New pupil asymmetry or a sluggish reaction is urgent. A new fixed, dilated pupil together with declining consciousness is a critical red flag for deterioration and possible herniation.

Recognize the Cushing response

A Cushing response consists of hypertension, bradycardia, and abnormal or irregular respirations. This is a late and ominous pattern associated with increased ICP and possible brainstem compromise. Treat this pattern as critical and escalate immediately.

Respond to acute deterioration

Promptly reassess and communicate acute changes rather than waiting for the next scheduled check or for a second decline. Escalate a worsening level of consciousness, new pupil asymmetry or loss of reactivity, worsening motor responses, rising ICP, or a Cushing response. A new fixed, dilated pupil with declining consciousness requires urgent escalation.

For example, an adult with severe traumatic brain injury whose ICP rises from $17$ to $20$ to $24\ \text{mm Hg}$ over $15$ minutes while becoming harder to arouse has a concerning trend and worsening examination. The value above $22\ \text{mm Hg}$ meets the guideline treatment threshold described here, but the trend and clinical findings also inform interpretation. Follow local escalation protocols for acute changes.