The decision to intubate a neurologically injured patient requires careful judgement. The primary indication is failure to protect the airway — a GCS of 8 or below is the conventional threshold, reflecting the point at which the gag and cough reflexes are typically insufficient to prevent aspiration. However, a falling GCS trajectory, active vomiting in an obtunded patient, or clinical evidence of aspiration may all warrant intubation at a GCS above this level.

Intubation in neurologically injured patients carries specific risks. Laryngoscopy and intubation cause a surge in ICP — partly through stimulation of laryngeal reflexes and partly through the associated hypertensive response. To mitigate this, lignocaine (lidocaine) 1.5 mg/kg IV administered 2–3 minutes before laryngoscopy has been used as a means of blunting this ICP surge, though the evidence base is limited. More important is ensuring adequate depth of anaesthesia and analgesia before laryngoscopy — an under-anaesthetised patient who coughs and strains during intubation may experience a very large ICP surge.

The choice of induction agent matters. Ketamine was historically avoided in neuro-ICU because of concerns that it raised ICP, but more recent evidence suggests this concern was overstated and that in a patient who is haemodynamically compromised — for whom propofol-induced hypotension would be particularly harmful — ketamine’s haemodynamic-preserving properties may make it the safer choice. Propofol remains the standard induction agent in haemodynamically stable patients. Thiopental is used when burst suppression is specifically required (e.g. refractory status epilepticus).

Suxamethonium remains the neuromuscular blocking agent of choice for most emergency neuro-ICU intubations because of its rapid onset and short duration of action. Rocuronium at 1.2 mg/kg is an acceptable alternative, particularly when suxamethonium is contraindicated (hyperkalaemia, penetrating eye injury, burns >72 hours, known or suspected myopathy).