Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Impending cerebral herniation
Rapidly falling consciousness, new fixed or unequal pupils, extensor posturing, bradycardia with hypertension, seizure or acute focal deficit may indicate critical intracranial pressure or haemorrhage.
Action: Call emergency neurological and critical-care help within the treatment ceiling, use ABCDE care, elevate the head about 30 degrees with neutral neck, correct hypoxia and glucose and obtain urgent CT. Give dexamethasone promptly for suspected tumour-related oedema and use hyperosmolar therapy only under the acute specialist protocol while definitive surgery or radiotherapy is decided.
Synopsis
Recognise headache patterns that indicate intracranial mass effect or another neurological emergency, image before unsafe lumbar puncture, relieve tumour oedema with proportionate corticosteroid and coordinate neurosurgical, radiotherapy and comfort decisions.
Ask about onset speed, progression, morning or positional pattern, cough or strain, vomiting, seizure, cognition, focal symptoms and analgesic or steroid exposure.
First-line examination records consciousness, pupils, cranial nerves, power, sensation, coordination, gait, fundoscopy when feasible and vital signs.
Urgent non-contrast CT is first-line for acute haemorrhage, major mass effect and hydrocephalus; contrast MRI is the gold-standard definition of brain tumour and metastatic burden after stabilisation.
Key red flags
Thunderclap onset, meningism, fever, collapse or new neurological deficit requires immediate haemorrhage, infection and vascular assessment.
First-line serial neurological examinationFirst stepFirst line
Document arousal, pupils, cranial nerves, fields, speech, limbs, coordination, gait and fundoscopy to identify change and localisation.
Management branches
Emergency pressureStabilise and image before deterioration
Headache accompanies falling consciousness, new pupil change, focal deficit, repeated vomiting, seizure or late pressure signs.
Call neurological and critical-care help, use ABCDE care, elevate the head about 30 degrees, maintain neutral neck and correct hypoxia, hypotension and glucose disturbance.
Obtain urgent non-contrast CT and give dexamethasone promptly for suspected tumour oedema; use hyperosmolar treatment only through the acute specialist protocol.
Key medicines
Dexamethasone for tumour-related cerebral oedemaUse 4 to 8 mg orally or intravenously daily for moderate symptomatic tumour oedema and up to 16 mg daily for severe pressure symptoms under the local neuro-oncology protocol, usually given once or in earlier divided doses with a documented taper.
Paracetamol for headacheFor an adult at least 50 kg without liver-risk factors, give 500 mg to 1 g orally every 4 to 6 hours as required, maximum 4 g in 24 hours; reduce the maximum for low weight, malnutrition, alcohol excess or hepatic disease.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.