Elevated ICP Induction: BTF Tier 1 → Tier 3

CPP = MAP − ICP. Goal: CPP ≥60-70 mmHg in adults with TBI (Brain Trauma Foundation 2016 guidelines). ICP ≤22 mmHg (raised from prior <20). Two enemies: hypotension (drops CPP from below) and intracranial hypertension (drops CPP from above). Either alone, or both together, drives secondary brain injury. The Monro-Kellie doctrine: skull is a fixed-volume box → ↑ blood + ↑ CSF + ↑ tissue (edema) ALL push other components out (CSF → spinal column, then venous blood compresses, then brain tissue herniates).

Etomidate 0.3 mg/kg IV (preserves SVR + cerebral perfusion). OR Propofol 1-2 mg/kg IV titrated (drops ICP via CMRO₂ reduction; watch SBP). Lidocaine 1.5 mg/kg IV pre-induction (blunts cough/sympathetic surge during DL — a classic ICP spike trigger). Fentanyl 1-2 mcg/kg or sufentanil 0.5 mcg/kg (blunts intubation surge; minimal hemodynamic effect at these doses). Rocuronium 1.2 mg/kg or vecuronium 0.1 mg/kg (avoid succinylcholine if possible — small transient ICP spike from fasciculation; not absolute contraindication, but rocuronium-with-sugammadex is preferred). KETAMINE: historically avoided; modern data shows safe + may reduce ICP in already-sedated patient. AVOID nitrous oxide (cerebral vasodilator).

Head of bed 30°. Loose cervical collar (don't compromise venous outflow). Normocapnia (PaCO₂ 35-40 mmHg) — NOT hyperventilation routinely (causes vasoconstriction + ischemia). Sedation + analgesia + muscle relaxation. Maintain MAP within 10% of baseline (CPP target 60-70). Maintain core temperature 36-37.5°C (avoid fever — drives metabolic demand + ICP up). Glucose 140-180. Sodium 135-150. Avoid hypoxia (PaO₂ ≥80, SpO₂ ≥95%). PEEP up to 15 cmH₂O acceptable (long-debunked myth that PEEP raises ICP — only at very high levels in dehydrated patients).

Hypertonic saline 3% (250 mL bolus over 20 min) OR mannitol 0.5-1 g/kg (24% solution; max 100 g). Both lower ICP via osmotic gradient pulling water out of brain. Mannitol: faster onset (10-15 min), shorter duration (3-4 hr), causes diuresis. Hypertonic saline: longer-lasting, no diuresis, useful in hypotensive patients. Watch sodium (target 145-155). Watch osmolality (cap at 320 mOsm/kg with mannitol). Mild hyperventilation acceptable (PaCO₂ 30-35) for transient ICP spike — NOT prolonged. CSF drainage if external ventricular drain in place.

Decompressive craniectomy — removes the constraint of the rigid skull. Best evidence in young patients with diffuse swelling; controversial in elderly. Barbiturate coma — pentobarbital 5-10 mg/kg load + 1-3 mg/kg/hr infusion to EEG burst suppression. Drops CMRO₂ + ICP. Profound hypotension + cardiac depression risk; A-line, vasopressors, +/- inotropes; ICU support. Therapeutic hypothermia (33-36°C) — controversial after Eurotherm and POLAR trials showed no mortality benefit + complications; ICU-level commitment. Aggressive hyperventilation (PaCO₂ <30) — emergency only, brief, while preparing definitive intervention.

Sudden + sustained ICP rise during craniotomy or non-cranial surgery in TBI patient. Move sequentially through: (1) Confirm not a measurement artifact (zero, drainage). (2) Tier 1 fast: head up, neutral neck, deepen anesthesia, lidocaine bolus, normocapnia, normothermia, MAP target. (3) Tier 2: hypertonic 3% NaCl 250 mL bolus OR mannitol 1 g/kg. (4) Communicate with surgeon — slowing or pausing the case may be needed. (5) Look for surgical/positional cause: head of bed lowered, neck rotated, retractor pressure, hyperventilation withdrawn, sedation lightened. (6) If the patient shows signs of herniation (Cushing reflex: HTN + bradycardia + irregular respirations) — call neurosurgery immediately for emergent decompression.