TBI nursing: assessment, interventions, and NCLEX review

Traumatic brain injury (TBI) is a disruption in normal brain function caused by an external mechanical force — a blow, jolt, or penetrating injury to the head. It is one of the leading causes of death and disability in the United States, and it is a high-yield topic across every NCLEX domain from physiological adaptation to reduction of risk potential. Nurses at the bedside are the first line of defense against the most dangerous aspect of TBI: not the initial impact, but the cascade of events that unfolds in the hours and days afterward. Understanding TBI classification, pathophysiology, and the priority nursing interventions will prepare you to detect deterioration early, act correctly under pressure, and pass the hardest neuro questions the NCLEX can generate.

Fast-scan: TBI key facts

TBI classification

By severity: the GCS framework

The Glasgow Coma Scale (GCS) is the universal language of TBI severity. Scores range from 3 (no response) to 15 (fully alert and oriented). Classification by initial GCS guides triage decisions, monitoring intensity, and intervention thresholds.

Mild TBI (GCS 13–15): Often called concussion, mild TBI accounts for the majority of cases. Patients may have a brief loss of consciousness (less than 30 minutes), post-traumatic amnesia under 24 hours, or simply a period of altered consciousness. The GCS recovers to 13–15 within the first hour. Most patients are discharged from the emergency department with return-precaution instructions, though a subset develop prolonged post-concussion syndrome.

Moderate TBI (GCS 9–12): These patients require admission and close monitoring. Loss of consciousness may last up to 24 hours; post-traumatic amnesia extends from 1 to 7 days. CT imaging is mandatory. A meaningful proportion of moderate TBI patients will deteriorate — the GCS can fall rapidly if a hematoma expands or cerebral edema develops. Serial neuro checks are essential.

Severe TBI (GCS ≤8): A GCS of 8 or below is the clinical threshold for airway protection and intubation. Patients cannot maintain a patent airway, are at high risk for aspiration, and require intensive care monitoring. Loss of consciousness exceeds 24 hours. This population carries significant mortality and disability risk, and the focus of nursing care shifts decisively toward prevention of secondary injury.

Primary versus secondary injury

This distinction is fundamental to understanding TBI nursing care.

Primary injury occurs at the moment of impact. The mechanical forces — acceleration, deceleration, rotation, direct contact — cause immediate neuronal death, axonal disruption, and vascular tearing. Nothing the nurse does reverses primary injury; it is done when the patient arrives.

Secondary injury is everything that happens afterward. It unfolds over hours to days through a cascade of metabolic, vascular, and inflammatory processes. Secondary injury is where nursing saves lives. Hypoxia, hypotension, elevated ICP, fever, hyperglycemia, and seizures all worsen secondary injury — and every one of them is a nursing-modifiable variable.

Focal versus diffuse injury types

Epidural hematoma (EDH): Arterial bleeding (classically the middle meningeal artery) between the skull and dura. CT shows a biconvex (lens-shaped) hyperdense collection. The hallmark presentation is a “lucid interval” — brief unconsciousness, apparent recovery, then rapid deterioration as the hematoma expands. This is a neurosurgical emergency.

Subdural hematoma (SDH): Venous bleeding between the dura and arachnoid. Crescent-shaped on CT. More common in elderly patients and those on anticoagulants. Acute SDH (within 72 hours) carries high mortality; chronic SDH may present weeks later with subtle cognitive changes.

Cerebral contusion: Bruising of brain parenchyma, often with coup (at impact site) and contrecoup (opposite side) lesions. Can expand over 24–48 hours — repeat CT is frequently ordered.

Diffuse axonal injury (DAI): Widespread shearing of axons throughout the white matter, typically from rapid acceleration-deceleration forces. CT is often unremarkable; MRI is more sensitive. DAI is the mechanism behind prolonged coma with a relatively normal CT scan and is associated with poor long-term outcomes.

Pathophysiology

The coup-contrecoup mechanism

When the skull decelerates suddenly — as in a fall or motor vehicle collision — the brain continues moving inside the cranial vault. The impact site sustains the coup injury; the brain then strikes the opposite inner skull surface, creating the contrecoup injury. Rotational forces layer additional shear stress across axonal tracts throughout the brain. The result is not a localized wound but a complex pattern of focal and diffuse damage.

Blood-brain barrier disruption and cerebral edema

Mechanical trauma disrupts the tight junctions of the blood-brain barrier within minutes. Vasogenic edema follows: plasma proteins and fluid leak into brain extracellular space, driving brain volume up. Simultaneously, injured neurons lose the ability to maintain their sodium-potassium gradient, causing intracellular swelling (cytotoxic edema). Both processes expand brain volume inside the rigid skull — with consequences described by the Monro-Kellie doctrine.

The Monro-Kellie doctrine

The skull is a closed, non-expandable box containing three compartments: brain tissue (~80%), cerebrospinal fluid (~10%), and blood (~10%). Total volume is fixed. When brain volume increases from edema — or when a hematoma occupies space — CSF and venous blood are displaced to compensate. This compensation is finite. Once compensatory capacity is exhausted, ICP rises sharply and steeply. Normal ICP is 0–15 mmHg. When ICP exceeds 20–22 mmHg, cerebral perfusion is threatened. This is the tipping point between survivable injury and herniation.

The secondary injury cascade

The key chain of events in secondary TBI runs as follows:

Hypoxia → neurons shift to anaerobic metabolism → lactic acid accumulates → cellular acidosis → membrane failure → cytotoxic edema → ↑ICP → ↓CPP → ischemia → more hypoxia.

Hypotension compounds this at every step. A single episode of SBP below 90 mmHg nearly doubles TBI mortality. Even brief hypotension reduces cerebral perfusion pressure below the brain’s autoregulatory floor, converting an injury with good potential for recovery into one with permanent ischemic damage.

Cerebral perfusion pressure (CPP) = MAP − ICP. The Brain Trauma Foundation guidelines target CPP of 60–70 mmHg for most severe TBI patients (minimum 50 mmHg). When ICP rises or MAP falls, CPP drops — and the brain ischemia accelerates. Every nursing intervention in TBI management can be understood as an effort to keep ICP low and MAP adequate.

Excitotoxicity adds another dimension: damaged neurons release excessive glutamate, which overstimulates NMDA receptors, flooding neurons with calcium and triggering apoptosis. This process continues for hours after the initial injury, explaining why patients can appear stable and then deteriorate.

Nursing assessment

The Glasgow Coma Scale

The GCS is the core neuro assessment tool in TBI. It evaluates three domains:

• Eye opening (E): Spontaneous = 4 | To voice = 3 | To pain = 2 | None = 1
• Verbal response (V): Oriented = 5 | Confused = 4 | Words = 3 | Sounds = 2 | None = 1
• Motor response (M): Obeys commands = 6 | Localizes pain = 5 | Withdraws = 4 | Flexion (decorticate) = 3 | Extension (decerebrate) = 2 | None = 1

Total = E + V + M. Range: 3–15. A drop of 2 or more points from baseline is a red flag requiring immediate physician notification. GCS ≤8 = severe TBI = intubation threshold.

For a complete breakdown of GCS scoring with clinical examples, see the Glasgow Coma Scale reference.

Pupillary assessment

Pupils are assessed for size, equality, and reactivity (PERRLA = Pupils Equal, Round, Reactive to Light, Accommodation). In TBI, pupil changes are among the most urgent clinical findings:

• Unequal pupils (anisocoria) or a fixed dilated pupil: Classic sign of uncal herniation — the herniated uncus compresses cranial nerve III, which controls pupillary constriction. A blown pupil is a neurosurgical emergency.
• Bilateral fixed and dilated pupils: Suggests bilateral herniation or severe brainstem injury. Ominous prognostic sign.
• Pinpoint pupils: May indicate pontine injury or opioid administration — distinguish carefully.

Cushing’s triad

Cushing’s triad is the classic late sign of dangerously elevated ICP approaching herniation:

1. Hypertension (widened pulse pressure — systolic rising while diastolic holds)
2. Bradycardia
3. Irregular respirations (Cheyne-Stokes, Biot’s, or ataxic patterns)

This is the brain’s last-ditch attempt to maintain cerebral perfusion by raising MAP. When you see Cushing’s triad, herniation is imminent. Do not wait for confirmatory orders — activate the rapid response immediately.

Serial neuro check frequency

In severe TBI, neuro checks are typically every 1–2 hours in stable patients and every 15–30 minutes in the acute phase or during any period of instability. Each check documents: GCS score by component, pupil size and reactivity bilaterally, limb strength, and vital signs.

Vital sign targets and red flags

Medical management overview

CT imaging

Non-contrast CT of the head is the first-line imaging study for all moderate and severe TBI and for mild TBI with red-flag features. CT rapidly identifies surgical emergencies — epidural hematoma, large subdural hematoma, significant contusion — and guides the decision for operative versus medical management. Many patients receive repeat CT at 6–12 hours to detect lesion expansion.

ICP monitoring

ICP monitoring is indicated for severe TBI (GCS ≤8) with an abnormal CT scan, and for severe TBI with a normal CT scan if two or more of the following are present: age >40, unilateral or bilateral motor posturing, or SBP <90 mmHg.

Two devices are commonly used:

• External ventricular drain (EVD): A catheter placed into the lateral ventricle. It provides the most accurate ICP readings and allows therapeutic CSF drainage to reduce pressure. Nursing responsibility includes maintaining a closed, sterile system; leveling and zeroing the transducer at the foramen of Monro (external auditory meatus); and monitoring CSF characteristics.
• Intraparenchymal monitor (bolt/Camino): A fiber-optic probe inserted into brain parenchyma. Accurate, lower infection risk than EVD, but does not allow CSF drainage.

For a detailed breakdown of ICP monitoring devices and EVD nursing care, see the ICP nursing reference.

Hyperosmolar therapy

Osmotic agents reduce cerebral edema by drawing fluid out of brain tissue into the vascular compartment.

Mannitol (0.25–1 g/kg IV bolus): Works within 15–30 minutes, peaks at 60–90 minutes. An osmotic diuretic — it will lower blood pressure through diuresis, so it must be used cautiously in hemodynamically unstable patients. Monitor serum osmolality (hold if >320 mOsm/kg to prevent renal failure) and urine output.

Hypertonic saline (3% NaCl): Effective hyperosmolar agent that does not cause diuresis, making it preferable in hypovolemic patients. Requires central venous access for higher concentrations. Monitor serum sodium and osmolality. Some centers use 23.4% NaCl as a bolus for acute herniation management.

Controlled hyperventilation

Hyperventilation lowers PaCO₂, causing cerebral vasoconstriction and reducing cerebral blood volume. This rapidly reduces ICP. However, it also reduces cerebral blood flow — which can worsen ischemia if used chronically. Standard guidance:

• Routine PaCO₂ target: 35–40 mmHg (normal range — avoid prophylactic hyperventilation)
• Acute herniation bridge therapy only: Target PaCO₂ 30–35 mmHg temporarily, while definitive intervention (osmotherapy, surgical decompression) is arranged

Nurses titrate ventilator settings in close collaboration with the intensivist and respiratory therapist.

Surgical intervention

Decompressive craniectomy — removing a portion of the skull to allow the swelling brain to expand outward rather than downward — is reserved for refractory elevated ICP not controlled by medical management. The bone flap is stored (often in the patient’s abdominal wall or a freezer) and replaced weeks to months later (cranioplasty) after swelling resolves.

Nursing interventions

Positioning

• Head of bed (HOB) 30–45°: Facilitates cerebral venous drainage, lowering ICP. This is a first-tier, zero-cost intervention that every TBI patient should receive unless there is a spinal injury contraindication.
• Head and neck midline: Lateral neck rotation compresses jugular veins, impairing venous outflow and raising ICP. Pillows and positioning aids should maintain neutral cervical alignment.
• Log-roll technique: If cervical spine clearance is pending, maintain spinal precautions during all turns.

Stimulation minimization and clustered care

Painful or stimulating procedures — suctioning, bathing, repositioning, phlebotomy — transiently spike ICP. Cluster care activities together with adequate rest intervals between clusters. Dim lights, minimize noise, limit unnecessary visitors. Coordinate with the team before suction or procedures in patients with borderline ICP values.

Normothermia

Fever increases cerebral metabolic rate of oxygen (CMRO₂), accelerating the secondary injury cascade. For every 1°C rise in body temperature, CMRO₂ increases approximately 7%. Target normothermia (36–37.5°C). Use acetaminophen, cooling blankets, or intravascular cooling catheters to control fever. Avoid shivering (a paradoxical response to cooling) — it raises metabolic demand and ICP.

Blood glucose control

Both hypoglycemia and hyperglycemia worsen TBI outcomes. Hypoglycemia directly starves neurons; hyperglycemia fuels the inflammatory and acidotic cascades. Target blood glucose 140–180 mg/dL per current neurocritical care consensus, with insulin infusions in the ICU when needed.

Seizure precautions and prophylaxis

Post-traumatic seizures (PTS) occur in up to 12% of severe TBI patients within the first 7 days. Seizures cause surges in ICP, hypermetabolism, and hypoxia — all catastrophic in an already-injured brain. Current guidelines recommend prophylactic antiseizure medication for high-risk patients:

• Levetiracetam is now preferred over phenytoin due to a more favorable side-effect profile and no requirement for therapeutic drug level monitoring.
• Prophylaxis duration: ≤7 days (early PTS prevention only — no evidence supports prolonged prophylaxis in reducing late seizures unless the patient has documented seizure activity).
• Maintain seizure precautions: padded side rails, suction at bedside, oxygen available, call light within reach.

DVT prophylaxis

TBI patients are at high VTE risk from immobility, brain-injury-associated hypercoagulability, and prolonged ICU stays. However, pharmacologic anticoagulation is complicated by intracranial hemorrhage.

• Mechanical prophylaxis (sequential compression devices, SCDs) begins immediately and is used in all patients.
• Pharmacologic prophylaxis (low-molecular-weight heparin or unfractionated heparin) is initiated only after neurosurgical clearance and follow-up CT confirms the hemorrhage is stable or resolving — timing is individualized.

Pain and sedation management

Adequate analgesia and sedation reduce ICP by blunting responses to stimulation. However, over-sedation masks the neurological exam. The guiding principle: use short-acting agents that allow regular neurological assessment windows.

• Fentanyl is preferred for analgesia — rapid onset and offset, minimal hemodynamic instability.
• Propofol is commonly used for sedation in mechanically ventilated patients; can be stopped briefly for exam windows.
• Avoid: Long-acting benzodiazepines that obscure the neuro exam for hours at a time.

Nutrition

Early enteral feeding within 24–48 hours is recommended for severe TBI. Brain injury is a hypermetabolic state — resting energy expenditure can increase by 40–200%. Early nutrition supports cellular repair, reduces infection risk, and preserves gut mucosal integrity. Nasogastric or post-pyloric feeding tubes are placed after airway is secured.

ICP nursing intervention summary

Herniation syndromes

When ICP rises to the point where brain tissue is forced from one compartment to another through fixed openings in the skull, herniation occurs. Herniation is immediately life-threatening. Recognizing the clinical presentation and initiating emergency nursing response without delay is essential.

Uncal (transtentorial) herniation

The uncus of the temporal lobe herniates downward through the tentorial notch, compressing the ipsilateral CN III and then the brainstem. Clinical presentation: ipsilateral fixed and dilated pupil (CN III compression), contralateral hemiplegia or hemiparesis, followed by deteriorating LOC. This is the classic herniation picture associated with epidural hematoma and expanding SDH.

Central (transtentorial) herniation

Diffuse cerebral edema or bilateral mass lesions drive the diencephalon and brainstem downward through the tentorium symmetrically. Presentation: bilateral small reactive pupils early (diencephalic stage), progressing to midposition fixed pupils as the midbrain is compressed, then to decerebrate posturing and brainstem failure.

Tonsillar herniation

The cerebellar tonsils are forced downward through the foramen magnum, directly compressing the medulla. Rapidly fatal without emergency intervention. Presents with sudden respiratory arrest, cardiovascular collapse, and loss of brainstem reflexes.

Emergency nursing response to herniation

1. Call rapid response / code immediately
2. Ensure head HOB 30° and head midline
3. Prepare for emergency hyperosmolar therapy (mannitol or hypertonic saline) per standing orders
4. Notify neurosurgery for emergent operative evaluation
5. Prepare for emergent hyperventilation (PCO₂ target 30–35 mmHg as temporary bridge)
6. Document time of onset and changes, pupil findings, GCS by component

NCLEX-style questions

Question 1. A patient with severe TBI has a blood pressure of 170/50 mmHg, heart rate of 44 bpm, and irregular respirations. Which finding is most consistent with this clinical picture?

A. Septic shock B. Neurogenic diabetes insipidus C. Cushing’s triad D. Autonomic dysreflexia

Answer: C — Cushing’s triad. Hypertension (with widened pulse pressure), bradycardia, and irregular respirations are the three components of Cushing’s triad — a late, ominous sign of dangerously elevated ICP and impending herniation. The nurse must notify the physician immediately and prepare for emergency interventions.

Question 2. A patient with a severe TBI has a MAP of 80 mmHg and an ICP of 18 mmHg. What is the patient’s cerebral perfusion pressure (CPP)?

A. 98 mmHg B. 62 mmHg C. 18 mmHg D. 80 mmHg

Answer: B — 62 mmHg. CPP = MAP − ICP = 80 − 18 = 62 mmHg. This falls within the target range of 60–70 mmHg. If MAP dropped or ICP rose, CPP would fall below the safe threshold.

Question 3. A nurse is positioning a patient with severe TBI and no spinal cord injury. Which position is the priority?

A. Flat (0°) to maximize cerebral perfusion B. Trendelenburg to increase MAP C. Head of bed 30–45° with head in midline D. Right lateral decubitus to prevent aspiration

Answer: C — HOB 30–45°, head midline. This position promotes cerebral venous drainage, lowering ICP without compromising MAP. Flat positioning worsens ICP. Trendelenburg raises ICP severely. Lateral rotation of the neck occludes jugular venous outflow and raises ICP.

Question 4. A patient with severe TBI is receiving mannitol 0.5 g/kg IV. Which nursing action is the highest priority?

A. Monitor serum osmolality and hold if >320 mOsm/kg B. Administer through a peripheral IV in the antecubital fossa C. Restrict IV fluids to prevent dilution of the drug D. Position the patient flat to maximize drug distribution

Answer: A — Monitor serum osmolality and hold if >320 mOsm/kg. Mannitol can cause acute tubular necrosis if serum osmolality exceeds 320 mOsm/kg. The nurse must monitor osmolality and urine output closely. Mannitol is also an osmotic diuretic — the nurse should anticipate high urine output and replace volume as ordered to prevent hypotension, which would worsen CPP.

Question 5. A nurse assessing a severe TBI patient notes that the right pupil has become fixed and dilated compared to the left. What is the most likely explanation?

A. The patient received a dose of atropine B. Uncal herniation is compressing CN III ipsilaterally C. The patient is experiencing normal sympathetic surge from pain D. The Cushing response is causing bilateral sympathetic activation

Answer: B — Uncal herniation compressing CN III ipsilaterally. Unilateral fixed and dilated pupil in TBI indicates that the uncus of the temporal lobe is herniating through the tentorial notch and compressing cranial nerve III. This is a neurosurgical emergency requiring immediate escalation. A blown pupil is never a benign finding in TBI.

Question 6. Which intervention is the highest priority for preventing secondary brain injury in a patient with severe TBI?

A. Administering prophylactic antiepileptics B. Starting full anticoagulation to prevent DVT C. Maintaining SBP ≥90 mmHg and SpO₂ ≥94% D. Keeping the patient NPO for the first 72 hours

Answer: C — Maintaining SBP ≥90 mmHg and SpO₂ ≥94%. The two most powerful drivers of secondary brain injury are hypotension and hypoxia. A single SBP episode below 90 mmHg nearly doubles TBI mortality. Hypoxia triggers the anaerobic cascade that leads to cytotoxic edema, ICP elevation, and herniation. Seizure prophylaxis is important but secondary; full anticoagulation is contraindicated in hemorrhagic TBI; early nutrition is recommended, not NPO.

Related articles

• Glasgow Coma Scale: complete scoring guide for nursing students
• Increased intracranial pressure (ICP): nursing assessment and interventions
• Meningitis nursing: assessment, interventions, and NCLEX review
• Stroke nursing: assessment, interventions, and NCLEX review
• Vital signs by age: normal ranges for nursing practice