Raised intracranial pressure — recognition, emergency management and IIH

Diagnosis: acute raised intracranial pressure with uncal herniation. The progressive morning headache plus the Cushing triad (hypertension with widened pulse pressure, bradycardia, irregular respiration) and a right fixed dilated pupil (third-nerve compression) with left hemiparesis (contralateral cerebral peduncle) localise to right uncal herniation — a neurosurgical emergency. Kareemi: the Cushing triad may be highly specific but is poorly sensitive. Seifert: it is an ominous sign of increased ICP and imminent brainstem herniation.^[1][8]

Immediate assessment — ABCDE. Airway: he is drowsy (GCS 12, falling) — prepare for intubation and ventilation (conventional teaching: GCS 8 or less; Kareemi: GCS 8 or below is sensitive but poorly specific for raised ICP). Breathing: Godoy/TBI oxygenation SpO2 95 percent or greater and/or PaO2 80 mmHg or greater (do not quote an undifferentiated SpO2 >94 percent table as the TBI floor). Circulation: defend the BTF age-stratified SBP floor (≥100 mmHg if 50 to 69 years; ≥110 mmHg if 15 to 49 or over 70) — this man is 54, so SBP ≥100 mmHg; treat the hypertension only by lowering ICP, not with antihypertensives. Disability: confirm pupils, GCS, glucose; fundoscopy (papilloedema may be absent acutely). Exposure: full sets, brief history for trauma/anticoagulation/bleeding risk.^[1][2][3]

Emergency bundle (lower ICP, protect CPP).^[4][2]

• Position — head of bed 30 degrees, neck midline (venous drainage).^[4]
• Normocapnia — Godoy: targeted PaCO2 35 to 40 mmHg. Intense or prolonged prophylactic hyperventilation is detrimental. A brief 15 to 30 min period targeting PaCO2 30 to 35 mmHg is reserved for acute neurological deterioration (Ramesh: short-term bag ventilation to PCO2 ≈ 30 mmHg if impending herniation). Do not quote PaCO2 4.0 to 4.5 kPa (~30 to 34 mmHg) as the resting target — that is hypocapnia, not Godoy normocapnia.^[3][4]
• Osmotherapy (first-line) — emergency herniation dose aligned with the stamped ED twin: mannitol 0.5 to 1 g/kg IV (2.5 to 5 mL/kg of 20 percent) OR hypertonic saline (Ramesh 3 percent, or Koenig 23.4 percent 30 to 60 mL). If the patient is stable, Kim allows 0.25–1 gm/kg slowly over 15 min to avoid hypotension. A fixed 250 mL 3 percent bolus is unit practice, not a trial-mandated volume. Give immediately given the clinical herniation.^[4][2][7]
• Normothermia; avoid hypoxia and hypotension. Kim: no consensus on the best glycaemic target in TBI — do not quote a millimole band as a BTF 4th number. Keep CPP 60 to 70 mmHg (CPP = MAP minus ICP); treat ICP above 22 mmHg (BTF 4th edition, 2016/2017 — not Hawryluk 2020).^[2]

Investigation — urgent non-contrast CT (NOT LP). CT identifies the mass (likely a right extradural, subdural or intracerebral haematoma given the acute course) and guides surgery. Lumbar puncture is contraindicated before imaging because of the risk of coning.^[1]

Definitive treatment and escalation. Immediate neurosurgical referral; definitive treatment is evacuation of the haematoma / mass lesion. If ICP is refractory, escalate to barbiturate coma (thiopentone) or decompressive craniectomy. Note: corticosteroids are harmful in traumatic raised ICP (CRASH: 2-week mortality 21.1 vs 17.9 percent, RR 1.18) — do not give them here; reserve steroids for vasogenic oedema (tumour/abscess).^[5]

Principles and pitfalls of osmotherapy. Mannitol risks hypovolaemia and hypotension (Kim: infuse slowly if stable). Fink: mannitol may precipitate acute renal failure if serum osmolarity exceeds 320 mOsm/L — a historical caution, not a BTF 4th-edition stop-rule. Hypertonic saline risks hypernatraemia; concentrated solutions often need central access. Reassess pupils and GCS after each dose as a bedside marker of response.^[2][6]