CCRN Neuro and Musculoskeletal Review: ICP and CPP, Stroke, Spinal Cord Injury, Compartment Syndrome

What Category D covers, and how this guide splits it

Category D of the Adult CCRN Test Plan (exams on and after November 12, 2025) is Musculoskeletal, Neurological, and Behavioral/Psychosocial, at 18%. That is about 22 or 23 of the 125 scored questions (Passy estimate; AACN publishes only the percentage), and the category grew from 14% under the 2020 test plan.

• Musculoskeletal (4 problems): compartment syndrome, fractures, muscular deconditioning, musculoskeletal trauma.
• Neurological (15 problems): among them acute spinal cord injury, brain death, encephalopathy, stroke, hydrocephalus, neurogenic shock, neurological storming, seizure disorders, neurosurgery and traumatic brain injury.
• Behavioral and psychosocial (10 problems): delirium, agitation, PICS, substance use and others, covered in the CCRN delirium and behavioral health guide.

The neuro nursing actions include continuous EEG monitoring, neuroendovascular interventions, ICP monitors and ventricular drains, neurosurgical procedures, seizure precautions, spinal precautions and swallow evaluation. On the musculoskeletal side, they are compartment syndrome and early mobility.

ICP and CPP arithmetic against the Brain Trauma Foundation thresholds

Cerebral perfusion pressure is the difference between mean arterial pressure and mean ICP, as the MSD Manual's traumatic brain injury chapter defines it: CPP = MAP − ICP. Use the MAP, not the systolic pressure, and subtract.

The Brain Trauma Foundation's Guidelines for the Management of Severe TBI, 4th edition, give the thresholds CCRN questions usually test:

• ICP: treating ICP above 22 mm Hg is recommended, because higher values are associated with increased mortality (Level IIB).
• CPP: the recommended target for survival and favorable outcomes is 60–70 mm Hg (Level IIB). Whether 60 or 70 is the true minimum is unclear and may depend on the patient's autoregulation.
• Avoid overshooting: avoiding aggressive attempts to keep CPP above 70 with fluids and pressors may be considered, because of the risk of respiratory failure (Level III).
• Ventilation: prolonged prophylactic hyperventilation to a PaCO2 of 25 mm Hg or less is not recommended (Level IIB).

Other references round these numbers differently. The MSD Manual, for example, gives a goal of ICP below 25 (sometimes 20) and CPP close to 60. Learn the BTF figures as the guideline numbers, and read each stem's thresholds as given.

Three worked cases (fictional patients with severe TBI):

The second row is the common trap. The CPP is only a point below target, but the ICP is above the treatment threshold, so "CPP is nearly adequate" is not the whole answer. With the arithmetic in hand, work the CPP calculation item in the free CCRN set →, which pairs a sustained ICP with a monitored MAP.

Stroke blood pressure timeline under the 2026 AHA/ASA guideline

The 2026 AHA/ASA Guideline for the Early Management of Patients With Acute Ischemic Stroke (published January 2026) sets blood pressure targets by treatment stage in section 4.3. The nursing work is keeping the pressure inside each window and recognizing when a reading blocks the next step.

Read the windows in order. A thrombolysis candidate whose pressure is above 185/110 mm Hg needs it brought below that line before the drug starts, and below 180/105 for at least 24 hours afterward. A tighter target after thrombolysis is not better in mild to moderate stroke.

Spinal cord injury, neurogenic shock, and spinal precautions

Neurogenic shock is loss of sympathetic vascular tone after spinal cord injury, commonly cervical or high thoracic injury, with hypotension and often relative bradycardia and warm skin. Exclude hemorrhage and other shock causes in trauma rather than attributing low pressure to the cord injury alone. Two related terms must be kept separate:

• Spinal shock is transient loss or depression of reflex and motor function below the injury. Reflex recovery evolves over days to weeks or longer; it is not the same as the circulatory problem of neurogenic shock.
• Autonomic dysreflexia is an episodic hypertensive emergency, usually in a person with an injury at T6 or above after the initial spinal-shock phase. Bladder distension, bowel problems, or other stimuli below the lesion can trigger it. It is not another name for early hypotensive neurogenic shock.

Avoid hypotension and hypoxia after acute spinal cord injury. The 2024 AO Spine/Praxis hemodynamic guideline weakly suggests augmenting MAP to a lower limit of 75–80 mm Hg, without actively augmenting beyond 90–95 mm Hg, for 3–7 days. Evidence is very low quality, so the team individualizes the target. The upper augmentation limit is not an instruction to lower a naturally higher MAP. Older references often quote 85–90 mm Hg for seven days; identify the guideline edition when comparing targets.

Spinal precautions are a listed nursing action. MSD notes that vertebral movement can happen even with a shift in the patient's position, such as during transport or the initial evaluation, and that unstable injuries stay immobilized until healed in alignment. Every turn, transfer and trip to imaging is a moment to keep the spine aligned under your unit's protocol.

Neurological storming and brain death: recognition first

Storming. The test plan says "neurological storming." The literature term is paroxysmal sympathetic hyperactivity (PSH). A 2020 review in Frontiers in Neurology (Zheng and colleagues) describes it as paroxysmal, transient increases in sympathetic activity, with six core features agreed by consensus: tachycardia, tachypnea, hypertension, hyperthermia, sweating and posturing. It is a diagnosis of exclusion: infection, rhabdomyolysis, dehydration, seizures, pulmonary embolism and deep vein thrombosis have to be ruled out first. For the nurse, that means documenting each episode, its features and possible triggers, and reporting new fever or tachycardia rather than assuming it is "just storming."

Brain death. The MSD Manual's chapter (reviewed July 2026), which cites the 2023 AAN/AAP/CNS/SCCM consensus guideline, describes brain death (death by neurologic criteria) as the total cessation of integrated brain function, especially brain stem function. Determination needs:

1. Prerequisites: a known catastrophic, permanent brain injury, with confounders excluded. Sedating or paralyzing drugs, hypothermia and reversible metabolic abnormalities must be ruled out or corrected first.
2. Examination: coma without brain-mediated motor responses, and absent brain stem reflexes (pupillary, corneal, cough or gag, oculocephalic and caloric).
3. Apnea test: no spontaneous breathing despite a carbon dioxide rise that meets the guideline's thresholds.

Spinal reflex movements can persist and do not by themselves invalidate the determination. Qualified clinicians complete the required examination and apnea testing under the applicable guideline and institutional policy; the nurse supports physiology and the family. Under federal hospital rules (42 CFR 482.45), the hospital notifies the organ procurement organization in a timely manner of imminent or actual deaths, and the family is approached about donation only by an OPO representative or a trained designated requestor. The ethics and family-care guide discusses these notification and communication duties.

Compartment syndrome: why palpable pulses mislead

The MSD Manual's compartment syndrome chapter (reviewed March 2025) gives the physiology behind the classic trap. Cell perfusion slows once compartment pressure passes normal capillary pressure, about 8 mm Hg. That is far below arterial pressure, so perfusion can stop long before pulses disappear. Pallor and pulselessness are late, ominous findings; their absence does not exclude the syndrome, and clinicians must not wait for them before evaluating suspected ischemia.

• Earliest symptom: pain out of proportion to the injury, made worse by passively stretching the muscles in the compartment. The compartment may feel tense.
• Confirmation: a compartment pressure above about 30 mm Hg, or within about 30 mm Hg of diastolic pressure.
• Initial treatment: remove any constricting cast, splint or dressing, correct hypotension, give analgesia and oxygen as needed, and watch potassium for hyperkalemia and rhabdomyolysis.
• Definitive treatment: urgent fasciotomy unless the pressure falls quickly and symptoms ease.

A fictional case. A sedated, ventilated patient after a motorcycle crash has a splinted forearm fracture. The forearm is tense, and she grimaces and her heart rate jumps each time the fingers are passively extended. Her radial pulse is strong. MSD notes that sedation and altered mental status make the clinical picture hard to read, so the response to passive stretch and the tense compartment carry the weight here. The nurse reports suspected compartment syndrome now, anticipates a compartment pressure measurement, and loosens the splint as ordered or per protocol. The free set's version is an awake patient with a splinted leg fracture. Test the compartment syndrome item with palpable pulses in the mixed CCRN set → to see whether the pulse finding pulls you toward a wrong option. For the rest of Category D, see the CCRN (Adult) test plan guide.