22.1 Increased Intracranial Pressure

CPHON Test Content Outline (TCO) V.F.1 tests increased intracranial pressure (ICP) as a neurologic emergency. The central-nervous-system (CNS) tumor chapter already localized morning vomiting to a posterior fossa mass and banned lumbar puncture (LP) through mass effect. The neurologic-effects chapter signposted a blown pupil away from a school meeting. This section is the hour the brain is tight: name the cause, protect the airway, keep venous drainage open, and do not send a child with mass effect for a diagnostic LP.

A 6-year-old who wakes vomiting and then stops answering, a 9-month-old whose fontanelle is tense and whose eyes look “sunset,” and a teenager with thrombocytopenia after a fall who becomes bradycardic and hypertensive are the same emergency at different ages. The Oncology Nursing Certification Corporation (ONCC) uses generic drug names. The Association of Pediatric Hematology/Oncology Nurses (APHON) picture is a nurse who elevates the head of bed, keeps the head midline, refuses hypotonic free water, and calls neurosurgery before waiting for Cushing triad to “confirm” herniation.

What is rising, and what pushes it

ICP is the pressure inside the skull. Blood, cerebrospinal fluid (CSF), and brain tissue share a rigid box. Add a brain tumor, hemorrhage, hydrocephalus, or cerebral edema, and something else must give—perfusion or herniation. Pediatric hematology/oncology triggers:

• Brain tumors (medulloblastoma, ependymoma, other posterior-fossa and supratentorial masses) and postoperative swelling.
• Hydrocephalus from fourth-ventricle obstruction or shunt or external ventricular drain (EVD) failure.
• Hemorrhage into tumor, after biopsy, or with coagulopathy and thrombocytopenia.
• Cerebral edema: vasogenic edema around tumors, cytotoxic edema after ischemia or severe metabolic injury, and edema in severe immune effector cell–associated neurotoxicity syndrome (ICANS) or fulminant CNS infection.

Vasogenic edema around tumors is the steroid-responsive map. Hydrocephalus is a CSF-drainage map. Hemorrhage is a coagulation-plus-neurosurgery map. Do not give dexamethasone and call every tight brain “treated.”

Recognition: morning clues, infant clues, late Cushing

Classic older-child clues: morning headache, vomiting (often without diarrhea), and papilledema. Recumbency raises venous pressure overnight; sitting up may briefly ease the headache. Diplopia, new irritability, a falling school-age Glasgow Coma Scale (GCS), and a child who “just is not himself” are neurologic until proven otherwise. Papilledema can lag in a hyperacute rise and can be hard to see without an ophthalmoscope; its absence does not clear the diagnosis.

Infants still have open sutures. They may not vomit on a school-age schedule. Watch a bulging fontanelle, sunsetting eyes (downward gaze with sclera visible above the iris), irritability, a high-pitched cry, poor feeding, and rapidly increasing head circumference. A 9-month-old with a tense fontanelle and sunset eyes has raised ICP even if someone says “the sutures will compensate.”

Cushing triad—hypertension, bradycardia, and irregular respirations—is late herniation physiology, not a screening test. Waiting for all three to fire before you act is how children code. Unequal or sluggish pupils, posturing, and apnea are the same late cluster. Treat the morning-vomiting, ataxic, or sunsetting child now.

Do not LP a child with mass effect, obstructive hydrocephalus, or a tight posterior fossa. Dropping lumbar pressure under a full compartment can cause downward herniation. CSF cytology waits until neurosurgery decompresses or clears the risk. Upright positioning does not make an unsafe LP safe. Absence of Cushing triad is not a green light.

First actions: airway, position, fluids, osmotherapy, steroids, drain

Airway is first. A falling GCS, pooling secretions, irregular respirations, or a child who no longer protects the tongue needs oxygen, positioning, suction at the ready, and a team that can intubate. Hypercarbia dilates cerebral vessels and raises ICP; hypoxia does the same. This is not a standing order for prophylactic hyperventilation on the floor. Brief hyperventilation is a herniation rescue used by airway-skilled teams, not a CPHON default for every headache.

Position: elevate the head of bed as ordered (many units use about 30 degrees—do not treat one number as an ONCC-published fact) and keep the head midline so jugular venous drainage is not kinked. Avoid tight tracheostomy ties, extreme neck flexion or rotation, and Trendelenburg. Cluster painful care so the child is not repeatedly coughing and straining. A screaming, flexed toddler with a full bladder is an ICP spike you can prevent with analgesia, a calm plan, and a working bladder.

Avoid hypotonic fluids. Free water (including many hypotonic maintenance bags) can worsen cerebral edema. Use isotonic fluids as ordered. Watch sodium: hyponatremia from the syndrome of inappropriate antidiuretic hormone secretion (SIADH) after vincristine or CNS disease is a metabolic-chapter cousin that still raises brain water.

Osmotherapy as ordered: hypertonic saline or mannitol. Hypertonic saline pulls water and needs serial sodium checks. Mannitol is an osmotic diuretic; place a Foley, watch output and blood pressure, and do not assume a dry hypotensive child is “decompressed.” These drugs belong on a monitored pathway, not as a hallway experiment.

Corticosteroids (typically dexamethasone) treat vasogenic edema around tumors. They are not a universal ICP drug for isolated hydrocephalus or an acute bleed. Give as ordered; do not skip gastric-protection teaching and do not stop them abruptly later.

Neurosurgery and an EVD treat obstructive hydrocephalus. EVD nursing—chamber height relative to the tragus, a closed sterile circuit, no casual raising or lowering when the bed moves—was taught with CNS tumors; here the emergency is to get the drain, not to argue about cytology. Shunt malfunction (headache, vomiting, lethargy, swelling along the tract, return of sunset eyes) is raised ICP until imaging says otherwise.

Walk the 6-year-old with two weeks of morning headache and vomiting who arrives sleepy with papilledema and a large posterior fossa mass. Sit the child up, head midline, oxygen, isotonic fluids, no LP, notify neurosurgery, steroids as ordered for vasogenic tumor edema, prepare for EVD. Walk the 9-month-old with a bulging fontanelle and sunsetting eyes: same map plus an infant airway watch. Walk the 14-year-old with a platelet count of 8,000/µL after a fall who develops hypertension and a falling heart rate: hemorrhage plus late Cushing—airway, platelets as ordered, imaging, neurosurgery, not a hypotonic fluid bolus and a morning clinic slot.

The CPHON product for TCO V.F.1 is a child whose head is up and midline, whose bag is not hypotonic, who did not get an LP through mass effect, who received osmotherapy and tumor-directed steroids as ordered, and whose airway was protected before Cushing triad was complete.