Craniotomy for tumour

Surgical approach

Positioning (supine/lateral/park-bench/sitting occasionally), head fixed in Mayfield pins; neuronavigation registration
- Key implications: immobility, pressure area/eye protection, venous drainage (head up, neutral neck), risk of VAE if sitting
Scalp incision → scalp flap → burr holes → bone flap (craniotomy) → dural opening
- Scalp and pinning are highly stimulating; dural manipulation can trigger haemodynamic responses
Tumour localisation (navigation/US), cortical mapping ± awake language/motor testing, tumour debulking and haemostasis
- Potential for brain swelling/bleeding; may request hyperventilation, mannitol/hypertonic saline, temporary hypotension, or burst suppression
Dural closure (watertight), bone flap replaced/fixed, scalp closure; drain sometimes
- Post-op imaging often planned; extubation decision based on neuro status/airway/bleeding risk

Anaesthetic management (overview)

Type of anaesthesia: usually GA; awake craniotomy for lesions near eloquent cortex; occasional monitored anaesthesia care with scalp block
Airway: ETT preferred (controlled ventilation, long duration, brain relaxation); SGA only in selected short cases with low aspiration risk and no need for tight CO2 control
Duration: typically 3–8 hours (variable with tumour size/location, mapping, haemostasis)
Pain: moderate; major noxious stimuli are Mayfield pins and scalp incision; intracranial brain tissue is relatively insensitive but dura/meninges are painful
Core aims: stable cerebral perfusion, good surgical field (brain relaxation), rapid wake-up for neuro exam, avoid secondary brain injury (hypoxia, hypotension, hypercarbia, hypo-/hyperglycaemia, pyrexia)

Pre-operative assessment

History: symptoms of raised ICP (headache, vomiting, papilloedema), seizures, focal deficits, cognitive/behavioural change; steroid use; anticoagulants/antiplatelets
Airway: consider reduced GCS, aspiration risk, obesity/OSA; plan for smooth induction and emergence
Neuro status: document baseline (GCS, pupils, focal signs) and pre-op language/motor function (important if awake mapping planned)
Imaging review: mass effect/midline shift/hydrocephalus; tumour location (posterior fossa = higher brainstem/airway risk); venous sinus proximity (bleeding risk)
Optimisation: treat nausea/vomiting, correct electrolytes (esp. Na+), manage diabetes; consider aspiration prophylaxis if raised ICP/vomiting
Drugs: steroids (dexamethasone) for vasogenic oedema; anticonvulsants if seizures; plan peri-op antibiotics; VTE prophylaxis strategy (mechanical early; chemical per local policy when safe)

Monitoring and access

Standard monitoring + invasive arterial line (beat-to-beat BP, blood gases, glucose); large-bore IV access (2 lines) ± central line if major blood loss anticipated
Temperature monitoring and active warming (avoid hypothermia; avoid hyperthermia which increases CMRO2)
Urinary catheter for long cases/diuresis with mannitol; consider neuromuscular monitoring if MEPs planned (often avoid or minimise NMB after intubation)
Depth of anaesthesia monitoring can help titration for rapid wake-up (especially TIVA); consider EEG-based monitoring if burst suppression requested

Induction and airway

Goals: avoid hypoxia/hypercarbia and large BP swings; maintain CPP (CPP = MAP − ICP)
Induction: propofol or thiopentone; opioid (remifentanil/fentanyl); consider lidocaine/esmolol to blunt response; muscle relaxant for intubation (rocuronium) then tailor to neuromonitoring needs
Ventilation: target normocapnia (PaCO2 ~4.5–5.0 kPa); mild hypocapnia (4.0–4.5 kPa) short-term if brain relaxation needed; avoid prolonged marked hypocapnia (ischaemia risk)
Airway: secure ETT well (head fixed, limited access); bite block if MEPs/awake phases; ensure eyes protected before draping

Maintenance of anaesthesia

Technique: TIVA (propofol + remifentanil) commonly preferred for stable ICP, rapid emergence, and compatibility with neurophysiology; volatile (≤1 MAC) acceptable but may increase CBF/ICP and interfere with MEPs at higher doses
Haemodynamics: maintain MAP to preserve CPP; treat hypotension promptly (vasopressors e.g. metaraminol/phenylephrine/noradrenaline); avoid hypertension (bleeding, oedema)
Fluids: aim euvolaemia; balanced crystalloid; avoid hypotonic fluids; glucose-containing fluids usually avoided unless indicated; consider goal-directed approach
Osmotherapy/brain relaxation: mannitol 0.25–1 g/kg or hypertonic saline per local protocol; ensure serum Na+/osmolality monitoring; coordinate timing with surgeon (after dura open often)
Analgesia: multimodal (paracetamol ± NSAID if acceptable bleeding risk), opioid-sparing with remifentanil infusion; consider low-dose longer-acting opioid near end to avoid remifentanil hyperalgesia
Scalp analgesia: scalp block (supraorbital, supratrochlear, zygomaticotemporal, auriculotemporal, greater/lesser occipital) and/or local infiltration for pins and incision; reduces haemodynamic surges and opioid need
Antiemesis: high risk; use multimodal (dexamethasone if not already, ondansetron, droperidol/cyclizine as appropriate)
Glycaemic control: avoid hyperglycaemia (worse neuro outcomes) and hypoglycaemia; check glucose intra-op (esp. steroids/diabetes)

Positioning considerations

Head-up and neutral neck to promote venous drainage; avoid jugular compression (tapes, extreme rotation/flexion)
Pressure areas: eyes (corneal abrasion/CRAO), face, shoulders, ulnar nerve; pad carefully; document checks after draping
Sitting position (less common): benefits surgical access/venous drainage but risks VAE, hypotension, pneumocephalus; requires specific monitoring and team readiness

Neurophysiological monitoring (if used)

SSEPs/MEPs: minimise volatile and avoid long-acting NMB (MEPs especially); maintain stable BP, temperature, and anaesthetic depth
Cortical mapping/awake testing: requires cooperative patient, excellent analgesia (scalp block), and ability to rapidly lighten anaesthesia without airway compromise

Emergence and post-operative care

Aim for smooth, rapid wake-up for neurological assessment; avoid coughing/straining (↑ICP, bleeding) using lidocaine, careful opioid titration, and BP control
Extubation criteria: awake, obeying commands, protective reflexes, stable haemodynamics/ventilation, acceptable brain swelling/bleeding risk; consider delayed extubation if posterior fossa, long surgery, major oedema, low GCS, significant blood loss
Post-op destination: PACU with neuro obs vs HDU/ICU depending on case complexity, comorbidity, intra-op events, and need for ventilation
Post-op priorities: neuro observations, BP targets, analgesia without oversedation, antiemesis, fluid/electrolytes (Na+), glucose, temperature; early detection of haematoma, seizures, hydrocephalus, CSF leak

Key complications (anaesthetic relevance)

Intracranial haemorrhage/haematoma: hypertension, coagulopathy; presents with reduced consciousness, focal deficit, unequal pupils; urgent imaging/re-exploration
Brain swelling/raised ICP: hypercarbia, hypoxia, venous obstruction, excessive fluids; manage with head-up, optimise ventilation, osmotherapy, deepen anaesthesia, consider CSF drainage if available
Seizures: more common with cortical irritation; treat with benzodiazepine/propofol, correct metabolic causes, consider antiepileptic loading per local policy
Venous air embolism (especially sitting): sudden fall ETCO2, hypoxia, hypotension, mill-wheel murmur; manage with flood field, aspirate via CVC if present, 100% O2, support circulation, left lateral/head-down if feasible
Pneumocephalus/tension pneumocephalus: headache, agitation, neuro deterioration; avoid nitrous oxide; treat with high-flow O2 and neurosurgical review
Electrolyte disorders: SIADH/CSW; diabetes insipidus (more with pituitary surgery but can occur); monitor urine output and Na+

You are asked to anaesthetise a patient for elective supratentorial tumour resection. What are your anaesthetic goals?

Structure around cerebral physiology and surgical requirements.

Maintain cerebral perfusion and oxygenation: avoid hypoxia, hypotension; maintain appropriate MAP for CPP
Optimise surgical conditions: brain relaxation (head-up, normocapnia/mild temporary hypocapnia, osmotherapy), minimise venous congestion
Provide immobility and stable operating field; anticipate intense stimuli (pins/incision/dura)
Enable rapid, smooth emergence for early neurological assessment; avoid coughing/straining and hypertension
Prevent secondary brain injury: normothermia, glucose control, avoid hypo-osmolar fluids, treat seizures and nausea/vomiting

How does your choice of anaesthetic technique affect intracranial pressure and neurophysiological monitoring?

Common FRCA theme: CBF/CMRO2 coupling and monitoring compatibility.

Propofol-based TIVA reduces CMRO2 and CBF → tends to lower ICP and gives predictable wake-up
Volatile agents cause dose-dependent cerebral vasodilation → ↑CBF/CBV and may increase ICP (especially if ventilation not controlled)
High volatile concentrations and N2O can worsen brain relaxation; avoid nitrous oxide (air expansion, pneumocephalus risk)
MEPs are particularly sensitive to volatiles and neuromuscular blockade; prefer TIVA and minimal/short-acting NMB after intubation
Maintain stable physiology (MAP, CO2, temperature) to preserve SSEP/MEP signal quality

What is a scalp block? Which nerves are blocked and what are the benefits/risks?

Frequently examined in neuroanaesthesia vivas, especially for awake craniotomy and haemodynamic control.

Blocks sensory nerves of scalp: supraorbital, supratrochlear, zygomaticotemporal, auriculotemporal, greater occipital, lesser occipital (± greater auricular depending on incision)
Benefits: blunts response to Mayfield pins/incision, reduces opioid requirement, improves haemodynamic stability, facilitates awake craniotomy comfort
Technique: landmark or US-guided injections with local anaesthetic; also local infiltration at pin sites
Risks: local anaesthetic systemic toxicity (large volumes), intravascular injection (scalp vascular), haematoma, nerve injury; calculate maximum dose and aspirate frequently

The surgeon says the brain is 'tight'. Give a stepwise approach to improving brain relaxation.

Answer should be systematic: position/venous drainage, ventilation, depth, fluids/osmotherapy, surgical causes.

Check basics: head-up, neutral alignment, ensure no neck/ETT tie/jugular compression; ensure adequate anaesthetic depth and analgesia
Ventilation: ensure normocapnia; consider short-term mild hypocapnia; exclude circuit/ETT obstruction and high airway pressures
Haemodynamics/venous congestion: avoid excessive PEEP; treat hypertension; ensure adequate venous return
Fluids: stop hypotonic fluids; avoid over-resuscitation; consider diuresis if overloaded
Osmotherapy: mannitol or hypertonic saline; coordinate timing; monitor Na+/osmolality and urine output
Consider surgical factors: haematoma, hydrocephalus/CSF drainage, venous outflow obstruction by retractors; discuss with surgeon

How would you manage blood pressure during tumour resection and why?

Examiners want CPP-focused reasoning and avoidance of bleeding.

Set patient-specific targets: maintain MAP to preserve CPP, especially with raised ICP or impaired autoregulation
Avoid hypertension: reduces risk of intracranial bleeding and brain oedema; treat with deepening anaesthesia, opioid, beta-blocker/vasodilator as appropriate
Treat hypotension promptly: vasopressors (phenylephrine/metaraminol/noradrenaline) and address causes (anaesthetic depth, bleeding, venodilation)
During critical phases (e.g., aneurysm not relevant here, but tumour near major vessels): close communication; avoid sudden swings

Describe your approach to emergence and extubation after craniotomy for tumour.

Common FRCA scenario: balancing early neuro exam vs airway/bleeding risk.

Plan for rapid wake-up: stop hypnotic/short-acting opioid in time; ensure normocapnia, normothermia, adequate reversal if NMB used
Smooth extubation: prevent coughing/straining (lidocaine, careful opioid titration, suction under deep plane if appropriate); control BP
Extubate if: awake, obeying commands, stable ventilation/haemodynamics, no major brain swelling/bleeding concerns, airway safe
Delay extubation if: low GCS, posterior fossa/brainstem involvement, prolonged surgery, significant oedema/bleeding, difficult airway concerns, hypothermia, major metabolic derangement
Post-op: neuro obs, analgesia/antiemesis, BP targets, urgent CT if deterioration

What are the causes of delayed wake-up after craniotomy and how would you investigate/manage it?

High-yield differential: drugs, metabolic, neurological catastrophe.

Drug causes: residual anaesthetics/opioids, residual NMB, benzodiazepines, hypothermia; check TOF, consider naloxone/flumazenil cautiously if appropriate
Metabolic/physiological: hypoxia, hypercarbia, hypo/hyperglycaemia, electrolyte disturbance (Na+), acid-base issues
Neurological/surgical: intracranial haemorrhage, cerebral oedema, infarct, hydrocephalus, seizures/non-convulsive status, tension pneumocephalus
Approach: ABCs, check gases/glucose/electrolytes/temp, review drugs given, neuro exam (pupils), urgent CT head and neurosurgical discussion if concern

Venous air embolism: when is it a risk in tumour craniotomy, what are the signs, and how do you manage it?

Often asked when sitting position or non-collapsible venous sinuses are involved.

Risk situations: sitting position, head elevated above heart, open venous sinuses/diploic veins, hypovolaemia
Signs: sudden fall in ETCO2, hypoxia, hypotension, tachyarrhythmias; possible 'mill-wheel' murmur; increased pulmonary pressures if monitored
Immediate actions: inform surgeon, flood field with saline and apply bone wax/pressure; 100% O2; stop N2O if used; support circulation with fluids/vasopressors
If CVC in place: attempt aspiration from RA; consider repositioning (left lateral/head-down) if feasible without compromising surgery
Escalate: CPR if cardiovascular collapse; consider TEE/precordial Doppler in high-risk cases

Outline an anaesthetic plan for an awake craniotomy for tumour near Broca’s area.

Key is patient selection, analgesia, airway strategy, and managing seizures.

Pre-op: detailed explanation, assess anxiety/claustrophobia, ability to cooperate; baseline language assessment; plan antiemesis and seizure strategy
Analgesia: meticulous scalp block + pin site infiltration; consider dexmedetomidine/propofol/remifentanil titrated sedation with spontaneous ventilation
Airway: plan for rescue (nasal airway, LMA, or asleep conversion); ensure access despite drapes; capnography and oxygen delivery
Mapping phase: lighten sedation for language testing; avoid oversedation/hypercarbia; maintain patient comfort and communication
Complications: seizures during stimulation (treat with cold saline to cortex, benzodiazepine/propofol), nausea/vomiting, agitation, airway obstruction; have clear conversion-to-GA plan

Discuss fluid therapy in craniotomy for tumour.

Examiners want avoidance of cerebral oedema and maintenance of perfusion.

Aim euvolaemia; avoid hypotension and avoid fluid overload (worsens brain swelling)
Use isotonic balanced crystalloids; avoid hypotonic solutions; glucose solutions only if indicated and with monitoring
Colloid use depends on local practice; consider blood products if significant blood loss; monitor Hb and coagulation
Osmotherapy causes diuresis and electrolyte shifts: monitor urine output, Na+, osmolality; replace losses appropriately

What are the key post-operative complications after tumour craniotomy and how would you detect them early?

Focus on time-critical complications and bedside signs.

Intracranial haematoma/bleeding: decreasing consciousness, new focal deficit, headache, vomiting, pupillary changes → urgent CT
Cerebral oedema/raised ICP: agitation, reduced GCS, hypertension/bradycardia, vomiting; ensure airway/ventilation and urgent neurosurgical review
Seizures (including non-convulsive): altered mental state, subtle twitching; consider EEG if concern
Electrolyte disturbances (SIADH/CSW): confusion, seizures; monitor Na+ and fluid balance
PONV and pain: treat aggressively to avoid hypertension/straining; use multimodal therapy

Describe the anaesthetic management of a patient with raised intracranial pressure undergoing craniotomy for tumour.

A common FRCA long viva/SAQ theme: integrate physiology with practical steps.

Pre-op: assess signs of raised ICP; avoid sedative premedication if reduced consciousness; aspiration prophylaxis if vomiting; continue steroids/antiepileptics; plan arterial line and 2 IVs
Induction: smooth, controlled; avoid hypoxia/hypercarbia; propofol/thiopentone + opioid; consider lidocaine/esmolol; maintain MAP (vasopressors ready)
Ventilation: controlled ventilation with normocapnia; mild temporary hypocapnia if acute brain swelling; avoid high PEEP and venous obstruction
Maintenance: TIVA preferred; temperature and glucose control; isotonic fluids; avoid N2O; scalp block to reduce sympathetic surges
Brain relaxation: head-up, osmotherapy (mannitol/HTS), consider furosemide if needed; coordinate with surgeon; monitor electrolytes and urine output
Emergence: smooth wake-up; avoid coughing/hypertension; extubate only if safe; otherwise ventilate and transfer to ICU; urgent CT if delayed wake-up or deterioration

Discuss the advantages and disadvantages of total intravenous anaesthesia versus volatile-based anaesthesia for intracranial tumour surgery.

Often appears as an SAQ or viva comparison question.

TIVA advantages: reduced CBF/ICP, excellent conditions, rapid predictable emergence, less interference with MEPs, less PONV (relative)
TIVA disadvantages: infusion errors/awareness risk if delivery failure, propofol infusion syndrome risk (rare in this context), requires pumps and careful titration
Volatile advantages: easy titration, bronchodilation, familiarity; can be used at low MAC with opioid
Volatile disadvantages: dose-dependent cerebral vasodilation (↑CBF/ICP), more PONV, greater suppression of MEPs at higher concentrations
Pragmatic answer: technique individualised to tumour location, monitoring requirements, and need for rapid neuro assessment; many centres favour TIVA for mapping/MEPs

How would you manage severe hypertension during Mayfield pin insertion and scalp incision?

Typical FRCA crisis-management viva: treat cause, prevent recurrence, avoid cerebral complications.

Immediate: confirm adequate depth/analgesia; increase remifentanil/propofol; ensure oxygenation and ventilation
Local measures: request additional local infiltration at pin sites/incision; perform/augment scalp block if not already done
Drug options: short-acting agents (esmolol, labetalol, nitroglycerin) tailored to HR and haemodynamics; avoid precipitous hypotension
Reassess: check for light anaesthesia/awareness risk; review infusion lines and pumps; document events and adjust plan for subsequent stimuli