Subarachnoid Hemorrhage

Quick Answer

Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space between the arachnoid and pia mater, most commonly caused by rupture of an intracranial aneurysm (85%). It affects 9-10 per 100,000 population annually with mortality of 30-50% and significant morbidity in survivors. Critical care management focuses on:

1. Early aneurysm securing within 24-72 hours (coiling or clipping) to prevent rebleeding (4% within 24 hours, 50% within 6 months if untreated)
2. Nimodipine 60 mg every 4 hours for 21 days (reduces poor outcomes by 40%, number needed to treat = 7)
3. Blood pressure control before aneurysm securing (SBP below 160 mmHg) to minimize rebleeding risk, then permissive hypertension after securing
4. Vasospasm monitoring and management (peaks day 7-10): transcranial Doppler, CT perfusion, induced hypertension, intra-arterial therapy
5. Hydrocephalus management (20-30% acute, 10-20% delayed): external ventricular drain, ventriculoperitoneal shunt
6. Complications: Rebleeding, vasospasm/DCI, hydrocephalus, seizures (8-18%), hyponatremia (SIADH, cerebral salt wasting), cardiac dysfunction

Grading: Hunt-Hess (I-V clinical severity), WFNS (I-V based on GCS and focal deficit), Fisher/modified Fisher (CT blood burden predicting vasospasm).

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CICM Exam Focus

What Examiners Expect

Primary Examination (Written)

• Pathophysiology of early brain injury and delayed cerebral ischemia
• Cerebral autoregulation failure, cerebral perfusion pressure management
• Vasospasm mechanisms: endothelin-1, nitric oxide depletion, cortical spreading depolarization

Second Part Fellowship (Written SAQ)

• Acute management of SAH (ABCDE approach, aneurysm securing strategies)
• Grading systems: Hunt-Hess, WFNS, Fisher scale and clinical significance
• Nimodipine mechanism and evidence base (trials, dosing, duration)
• Vasospasm diagnosis and treatment (TCD, CT perfusion, induced hypertension, intra-arterial therapy)
• Complications: rebleeding, hydrocephalus, DCI, seizures, hyponatremia

Second Part Fellowship (Viva/Hot Case)

• Systematic approach to deteriorating SAH patient (delayed neurological deterioration day 7)
• Coiling vs clipping decision-making (ISAT trial, anatomical considerations)
• Vasospasm management escalation (medical → endovascular)
• Hydrocephalus diagnosis and EVD management
• Prognostication and withdrawal of life-sustaining treatment discussions

Common Viva Stem

"A 52-year-old woman presents with sudden onset 'worst headache of life', vomiting, and photophobia. GCS 14 (E4V4M6), neck stiffness present, BP 185/105 mmHg. CT brain shows diffuse subarachnoid blood, Fisher grade 3. CTA demonstrates a 7mm anterior communicating artery aneurysm. How would you manage this patient?"

Expected approach:

1. ABCDE resuscitation (airway assessment, GCS 14 adequate, high-flow O₂)
2. Blood pressure control (IV labetalol/nicardipine, target SBP below 160 mmHg to minimize rebleeding)
3. Nimodipine 60 mg PO/NG every 4 hours for 21 days
4. Seizure prophylaxis (levetiracetam 1000 mg loading, then 500 mg BD for 3-7 days)
5. Urgent neurosurgical/interventional neuroradiology consultation for aneurysm securing (coiling vs clipping)
6. ICU admission for monitoring, prevent complications
7. Grading: Hunt-Hess II (severe headache, nuchal rigidity, no focal deficit), WFNS II (GCS 14, no deficit), Fisher 3 (thick blood, high vasospasm risk)

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Key Points

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Epidemiology

Incidence and Mortality

Subarachnoid hemorrhage accounts for 5-10% of all strokes but affects a younger population (mean age 50-55 years) compared to other stroke subtypes. The annual incidence is 9-10 per 100,000 population in Western countries, with significant geographic variation (higher in Japan and Finland: 20-25 per 100,000).[1][2]

Mortality and morbidity are devastating:

• 30-day mortality: 30-45%
• 1-year mortality: 40-50%
• 12-15% die before reaching hospital
• Only 30-50% achieve good functional outcome (modified Rankin Scale 0-2)[3]

The majority of deaths occur within the first 48 hours, primarily due to early brain injury (initial hemorrhage, rebleeding, elevated ICP) and subsequent complications (rebleeding, vasospasm, delayed cerebral ischemia).[4]

Risk Factors

Non-modifiable:

• Female sex (1.6:1 female:male ratio, likely hormonal factors)
• Age (incidence increases with age, peak 50-60 years)
• Family history (first-degree relative with SAH: 3-5 fold increased risk)
• Genetic syndromes: Autosomal dominant polycystic kidney disease (ADPKD), Ehlers-Danlos syndrome type IV, neurofibromatosis type 1, Marfan syndrome
• Ethnicity: Finnish, Japanese populations (2-3 fold higher incidence)

Modifiable:

• Hypertension: Most important modifiable risk factor (relative risk 2.5-3.0)[5]
• Smoking: Strongest modifiable risk factor (relative risk 2-4, dose-dependent)[6]
• Heavy alcohol consumption (greater than 150 g/week, relative risk 2.0-3.0)
• Cocaine and methamphetamine use (acute hypertension, vasculitis)
• Oral contraceptives (modest increase, relative risk 1.3-1.8)

Protective factors:

• Statin use (reduces aneurysm formation and rupture risk, observational data)
• Light-to-moderate alcohol consumption (inverse relationship in some studies)

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Aetiology and Pathophysiology

Causes of Subarachnoid Hemorrhage

Aneurysmal SAH (85%)

Rupture of saccular (berry) aneurysms, typically located at arterial bifurcations in the circle of Willis:

Aneurysm formation occurs due to:

1. Hemodynamic stress at arterial bifurcations → endothelial injury
2. Medial wall degeneration → loss of internal elastic lamina and smooth muscle
3. Inflammatory remodeling → matrix metalloproteinases, macrophage infiltration
4. Aneurysm growth → progressive wall thinning → rupture

Risk factors for rupture:[7][8]

• Size greater than 7 mm (rupture risk 0.5-1% per year for 7-12 mm, 2-4% for greater than 12 mm)
• Location: Posterior circulation, ACoA, PCoA (higher risk than MCA)
• Morphology: Irregular shape, daughter sacs, aspect ratio greater than 1.6
• Patient factors: Female sex, smoking, hypertension, family history

Non-aneurysmal perimesencephalic SAH (10%)

Distinct clinical entity characterized by:

• Blood distribution: Centered anterior to midbrain/pons, no extension to lateral Sylvian fissures or anterior interhemispheric fissure
• Negative angiography: No aneurysm on DSA or high-quality CTA/MRA
• Benign prognosis: Rebleeding rate below 1%, vasospasm rare, near-normal recovery[9][10]
• Cause: Presumed venous or capillary rupture (etiology unclear)

Other causes (5%)

• Arteriovenous malformation (AVM): 5-10% of SAH, younger patients (mean age 30-40 years)
• Trauma: Most common cause overall when including head injury
• Cerebral artery dissection: Vertebral artery dissection more common than carotid
• Mycotic aneurysm: Endocarditis, IV drug use (1-2% of SAH)
• Pituitary apoplexy: Sudden hemorrhage into pituitary adenoma
• Coagulopathy/anticoagulation: Rare cause of spontaneous SAH
• Cocaine/amphetamine use: Acute hypertension, vasculitis
• Reversible cerebral vasoconstriction syndrome (RCVS): Thunderclap headache, cortical SAH

Pathophysiology of Brain Injury

SAH causes brain injury through two distinct phases:

Early Brain Injury (0-72 hours)

Primary injury from initial hemorrhage:[11][12]

1. Acute ICP elevation: Blood in subarachnoid space → ICP spikes to 80-100 mmHg within seconds
2. Global cerebral ischemia: CPP = MAP - ICP → if ICP transiently equals or exceeds MAP, global ischemia occurs
3. Direct blood toxicity: Hemoglobin breakdown products → oxidative stress, inflammation
4. Blood-brain barrier disruption: Tight junction breakdown → vasogenic edema
5. Cortical spreading depolarization: Waves of neuronal/glial depolarization → energy failure → cell death

Clinical consequence: Early brain injury determines initial neurological grade (Hunt-Hess, WFNS) and accounts for 50% of mortality.

Delayed Brain Injury (4-14 days)

Delayed cerebral ischemia (DCI) develops in 30% of patients, typically days 4-14 (peak 7-10):[13][14]

Mechanisms (multifactorial, NOT solely vasospasm):

1. Vasospasm (arterial narrowing on angiography):

   • Occurs in 70% of patients with thick cisternal blood (Fisher 3/4)
   • Endothelin-1 release → sustained smooth muscle contraction
   • Nitric oxide depletion → loss of endothelial-dependent vasodilation
   • Structural changes: Smooth muscle proliferation, collagen deposition
   • CRITICAL CONCEPT: 70% with vasospasm do NOT develop DCI; 30% with DCI have NO vasospasm[15]

2. Microvascular dysfunction:

   • Capillary spasm, microthrombi formation
   • Endothelial injury → impaired cerebral autoregulation
   • Impaired oxygen/glucose delivery to brain tissue

3. Cortical spreading depolarizations (CSDs):

   • Recurrent waves of neuronal depolarization
   • Propagate through injured cortex for days after SAH
   • Detected in 90% of poor-grade SAH patients
   • Each CSD → increased metabolic demand + impaired blood flow → infarction[16]

4. Inflammation and thrombosis:

   • Platelet activation, microthrombi formation
   • Inflammatory cytokines (IL-6, TNF-α)
   • Endothelial activation → leukocyte adhesion

Clinical manifestation of DCI:

• New focal neurological deficit (hemiparesis, aphasia)
• Decreased level of consciousness (GCS decline ≥2 points)
• New infarction on CT/MRI (in absence of other causes)
• Develops days 4-14, peaks day 7-10
• Accounts for 7-10% of mortality and 10-15% of severe disability

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Clinical Presentation

Symptoms and Signs

Classic presentation (sudden onset "thunderclap headache"):

• "Worst headache of my life": 80-90% of patients
• Instantaneous onset (seconds): "like being hit on the head," "explosion in the head"
• Maximal at onset (vs gradual progression of migraine/tension headache)
• Vomiting: 70-80% (increased ICP)
• Loss of consciousness: 50-60% at ictus (transient global ischemia from ICP spike)
• Neck stiffness/meningismus: 70-80% (develops over hours as blood irritates meninges)
• Photophobia: 60% (meningeal irritation)
• Seizure at onset: 8-18% (more common with MCA aneurysms)[17]

Clinical signs by severity (Hunt-Hess grading):

World Federation of Neurosurgical Societies (WFNS) grading:

WFNS grading is more objective (uses GCS) than Hunt-Hess and preferred for clinical trials and prognostication.[18]

Sentinel Headache

Sentinel (warning) headache occurs in 30-50% of SAH patients days to weeks before major rupture:[19]

• Sudden severe headache (less severe than major SAH)
• Presumed "warning leak" or small rupture that spontaneously seals
• Often dismissed as migraine or tension headache
• CRITICAL: Identifying sentinel headache and diagnosing SAH prevents catastrophic rebleeding

Red flags for SAH (Ottawa SAH rule, 100% sensitivity):[20]

• Age ≥40 years
• Neck pain or stiffness
• Witnessed loss of consciousness
• Onset during exertion
• Thunderclap onset (instantly peaking pain)
• Limited neck flexion on examination

Focal Neurological Findings

Third nerve palsy (25% of PCoA aneurysms):

• Ptosis, mydriasis (dilated pupil), "down and out" eye position
• Compression of CN III as it passes adjacent to PCoA
• CRITICAL: Complete third nerve palsy (pupil involved) = surgical emergency → aneurysm compressing nerve

Hemiparesis/aphasia (MCA aneurysms):

• Hematoma extending into brain parenchyma
• Vasospasm/ischemia in MCA territory

Abulia, akinetic mutism (ACoA aneurysms):

• Bilateral frontal lobe injury
• Lack of spontaneous speech/movement despite preserved consciousness

Posterior fossa signs (basilar/PICA aneurysms):

• Cranial nerve deficits (diplopia, facial weakness, dysphagia)
• Ataxia, vertigo
• Altered consciousness (brainstem compression)

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Grading Systems

Fisher Scale (Radiographic)

Original Fisher scale (1980) predicts vasospasm risk based on CT appearance:[21]

Modified Fisher scale (Frontera 2006) better predicts DCI:[22]

Thick blood = completely fills ≥1 cistern or fissure. Thin blood = partially fills cisterns.

Clinical use: Modified Fisher 3/4 identifies high vasospasm risk → intensive TCD monitoring, aggressive nimodipine compliance.

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Investigations

Imaging

Non-contrast CT brain — First-line investigation

Sensitivity for SAH:[23]

• Within 6 hours: 98-100%
• Within 12 hours: 95%
• Within 24 hours: 85-90%
• After 1 week: 50% (blood resorbed)

CT findings:

• Hyperdense (bright) blood in subarachnoid space
• Distribution: Basal cisterns, Sylvian fissures, interhemispheric fissure, sulci
• Aneurysm location prediction:
  • Blood in interhemispheric fissure → ACoA aneurysm
  • Unilateral Sylvian fissure → MCA aneurysm
  • Interpeduncular cistern → basilar tip aneurysm
• Complications:
  • "Intraventricular hemorrhage (IVH): 20-30%"
  • "Intracerebral hemorrhage (ICH): 20-40%"
  • "Hydrocephalus: 20-30% acute, 10-20% delayed"
  • Midline shift, herniation (poor-grade SAH)

Lumbar puncture — If CT negative but high clinical suspicion

Indications:

• Thunderclap headache + negative CT greater than 6 hours after onset
• High clinical suspicion (Ottawa SAH rule positive)

Timing: Wait ≥6 hours after headache onset (allows hemoglobin metabolism to xanthochromia)

CSF analysis:[24]

• Red blood cells: Persistent RBC count across tubes 1→3→4 (vs traumatic tap with declining count)
• Xanthochromia (yellow discoloration from hemoglobin breakdown):
  • "Spectrophotometry (gold standard): Sensitivity 100%, specificity 90%"
  • "Visual inspection: Sensitivity 80%, specificity 95%"
  • Appears ≥6 hours after SAH, persists 2-4 weeks
• Opening pressure: Often elevated (greater than 25 cm H₂O)

CT angiography (CTA) — Aneurysm detection and characterization

Indications: All patients with confirmed SAH (unless contraindication)

Advantages:

• Sensitivity 95-98% for aneurysms ≥3 mm
• Identifies aneurysm location, size, morphology
• Rapid (5-10 minutes) vs DSA (1-2 hours)
• 3D reconstruction assists neurosurgical/endovascular planning

Limitations:

• False negatives: Very small aneurysms (below 3 mm), thrombosed aneurysms, bone artifact
• 15-20% of SAH have negative CTA → require DSA

Digital subtraction angiography (DSA) — Gold standard

Indications:

• Negative CTA but SAH confirmed (to detect small/thrombosed aneurysms)
• Complex aneurysms requiring detailed assessment
• Pre-procedural planning for coiling or clipping

Findings:

• 85% have single aneurysm
• 15-30% have multiple aneurysms (treat ruptured aneurysm first, identified by location matching blood distribution)
• 15-20% have negative DSA on first study:
  • Perimesencephalic pattern → benign, no repeat DSA needed
  • Non-perimesencephalic pattern → repeat DSA in 1-2 weeks (10-15% reveal aneurysm on repeat)

MRI/MRA brain

Indications:

• Negative CT and LP (rule out SAH mimics)
• Delayed presentation (greater than 1 week), MRI FLAIR hyperintensity in sulci
• Aneurysm characterization if CTA inconclusive

Findings:

• FLAIR hyperintensity in subarachnoid space (persists longer than CT)
• Aneurysm detection sensitivity 85-90% (inferior to CTA/DSA)

Laboratory Studies

Initial blood tests:

• Full blood count: Baseline hemoglobin, platelets
• Coagulation profile: PT/INR, aPTT (if anticoagulated, reverse urgently)
• Electrolytes: Sodium (hyponatremia develops in 30-50%, see complications)
• Troponin: Elevated in 20-30% (neurogenic cardiac injury, not MI)
• ECG: Arrhythmias, ST changes, QTc prolongation (neurogenic stunned myocardium)

Serial monitoring:

• Sodium (daily): Hyponatremia from SIADH or cerebral salt wasting
• Troponin (if elevated initially): Risk factor for cardiac complications
• Blood glucose: Hyperglycemia (greater than 10 mmol/L) associated with worse outcomes

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Management

Initial Resuscitation (ABCDE)

Airway and Breathing

Indications for intubation:

• GCS ≤8 (Hunt-Hess V, WFNS V)
• Inability to protect airway (absent gag reflex, excessive vomiting)
• Hypoxia (SpO₂ below 90%) or hypercarbia (PaCO₂ greater than 50 mmHg)
• Agitation/seizures refractory to sedation
• Anticipated deterioration (transport to angiography/OR, Hunt-Hess IV)

Intubation strategy:

• Rapid sequence induction with hemodynamic control
• Avoid hypertensive response (coughing, straining → ICP spike → rebleeding risk)
• Use short-acting agents: Fentanyl 1-2 mcg/kg, propofol 1-2 mg/kg or etomidate 0.2-0.3 mg/kg, rocuronium 1 mg/kg
• Maintain SBP below 160 mmHg during intubation (use esmolol bolus 0.5 mg/kg if needed)

Ventilator settings:

• Tidal volume 6-8 mL/kg ideal body weight
• PEEP 5 cm H₂O (higher PEEP may increase ICP)
• Target PaCO₂ 35-40 mmHg (avoid hyperventilation except for acute herniation)
• Target PaO₂ greater than 80 mmHg, SpO₂ greater than 94%

Circulation: Blood Pressure Management

CRITICAL CONCEPT: Blood pressure management differs before vs after aneurysm securing.

Before aneurysm secured (prevent rebleeding):[25][26]

• Target SBP below 160 mmHg (no high-quality RCT data, based on observational studies)
• Avoid excessive lowering (SBP below 120 mmHg) → may worsen cerebral perfusion
• First-line agents:
  • Labetalol 10-20 mg IV bolus, then infusion 0.5-2 mg/min (alpha and beta blocker)
  • Nicardipine infusion 5 mg/h, titrate by 2.5 mg/h every 5-15 min (max 15 mg/h)
  • Esmolol infusion 50-300 mcg/kg/min (very short-acting, easily titratable)
• Avoid: Nitroprusside (increases ICP via cerebral vasodilation), hydralazine (unpredictable response)

After aneurysm secured (maintain cerebral perfusion, prevent DCI):

• Permissive hypertension: Maintain SBP 140-160 mmHg or patient's baseline
• Induced hypertension if vasospasm/DCI develops (see vasospasm section)
• Avoid hypotension: SBP below 100 mmHg associated with cerebral ischemia

Fluid Management

• Euvolemia: Target CVP 8-12 mmHg, neutral to slightly positive fluid balance
• Isotonic crystalloid: 0.9% saline preferred (avoid hypotonic fluids → cerebral edema)
• AVOID routine "triple H" therapy (hypertension, hypervolemia, hemodilution):
  • Hypervolemia does NOT prevent vasospasm, increases risk of pulmonary edema
  • "Modern approach: Euvolemia + induced hypertension if DCI develops[27]"

Disability: Neurological Assessment

Serial GCS and focal neurology (hourly for first 24-48 hours):

• GCS decline ≥2 points → urgent CT brain (rebleeding, hydrocephalus, seizure, DCI)
• New focal deficit → urgent CT brain and neurology/neurosurgery review

Seizure management:

• Witnessed seizure: Benzodiazepines (lorazepam 0.1 mg/kg IV), load with antiepileptic (levetiracetam 1000 mg IV or fosphenytoin 20 mg PE/kg)
• Prophylaxis (controversial):
  • "Short-term (3-7 days): Levetiracetam 500 mg BD (less interaction than phenytoin)"
  • NOT recommended long-term (no benefit, potential harm from phenytoin)[28]

Exposure: Temperature and Glucose

• Normothermia: Target 36.5-37.5°C (fever greater than 38°C associated with worse outcomes)
• Normoglycemia: Target 6-10 mmol/L (tight control below 6 mmol/L may increase hypoglycemia risk)

Aneurysm Securing

Timing: Within 24-72 hours to prevent rebleeding (ideally within 24 hours if feasible).[29]

Rebleeding risk if untreated:[30]

• 4% within first 24 hours
• 15-20% within 14 days
• 50% within 6 months
• 70-80% mortality per rebleeding episode

Coiling vs Clipping Decision

ISAT trial (2002) — Landmark RCT comparing endovascular coiling vs surgical clipping:[31]

Study design:

• 2,143 patients with ruptured aneurysms suitable for either treatment
• Randomized to coiling vs clipping

Results (1-year outcomes):

• Death or dependency (mRS 3-6):
  • "Coiling: 23.5%"
  • "Clipping: 30.9%"
  • "Absolute risk reduction: 6.9% (NNT 14)"
  • "Relative risk reduction: 22.6%"
• Mortality:
  • "Coiling: 8.1%"
  • "Clipping: 10.1%"

Long-term follow-up (10 years):[32]

• Survival benefit persisted
• Rebleeding risk: Higher with coiling (2.6% vs 0.9% at 10 years) but overall low
• Seizure risk: Lower with coiling (8.1% vs 12.3%)

Clinical implication: Coiling preferred for aneurysms suitable for both treatments (anterior circulation, favorable anatomy).

Indications for COILING (endovascular):

• Anterior circulation aneurysms with favorable anatomy (narrow neck, small dome)
• Posterior circulation aneurysms (surgical access difficult)
• Poor-grade SAH (Hunt-Hess IV-V) → less invasive
• Elderly or medically unfit for craniotomy
• Patient preference

Indications for CLIPPING (surgical):

• Wide-necked aneurysms unfavorable for coiling
• MCA aneurysms with branch vessels arising from dome
• Large ICH requiring evacuation (clip aneurysm during same operation)
• Young patients (lower lifetime rebleeding risk)
• Recurrent aneurysm after previous coiling

Nimodipine Therapy

CRITICAL INTERVENTION: Nimodipine is the ONLY proven neuroprotective agent in SAH.

Evidence: British aneurysm nimodipine trial (1989):[33]

• 554 patients randomized to nimodipine 60 mg PO q4h vs placebo for 21 days
• Primary outcome (poor outcome at 3 months):
  • "Nimodipine: 27%"
  • "Placebo: 33%"
  • "Absolute risk reduction: 5.7% (NNT 7)"
  • "Relative risk reduction: 40%"
• Cerebral infarction reduced from 33% to 22%
• NO reduction in angiographic vasospasm (mechanism is neuroprotection, NOT vasospasm prevention)

Dosing:[34]

• Nimodipine 60 mg PO/NG every 4 hours (total 360 mg/day)
• Duration: 21 days (start immediately on diagnosis, continue for full 21 days)
• IV formulation: NOT recommended (excessive hypotension, no outcome benefit)

Mechanism:

• L-type calcium channel blocker (cerebral-selective)
• NOT primary vasodilator (does not prevent vasospasm)
• Neuroprotection: Reduces calcium influx → prevents neuronal death from cortical spreading depolarizations, microvascular dysfunction
• Modest blood pressure reduction (5-10 mmHg) → monitor for hypotension

Contraindications:

• Hypotension (SBP below 100 mmHg) → hold dose, restart when SBP greater than 100 mmHg
• Relative: Severe aortic stenosis, cardiogenic shock

Monitoring:

• Blood pressure before each dose
• If SBP below 100 mmHg → hold dose, give 250-500 mL crystalloid bolus, recheck BP in 1 hour
• Resume when SBP greater than 100 mmHg

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Vasospasm and Delayed Cerebral Ischemia

Definitions and Epidemiology

Vasospasm: Arterial narrowing on angiography (DSA, CTA, MRA) or elevated velocities on transcranial Doppler (TCD).

Delayed cerebral ischemia (DCI): Clinical deterioration (new focal deficit or ≥2 point GCS decline) OR new infarction on imaging, occurring 4-14 days after SAH, not attributable to other causes (rebleeding, hydrocephalus, seizure, metabolic).

Incidence:[35]

• Angiographic vasospasm: 70% of SAH patients
• Symptomatic vasospasm/DCI: 30% of SAH patients
• 70% with angiographic vasospasm do NOT develop DCI
• 30% with DCI have NO significant vasospasm (microvascular dysfunction, CSDs)

Risk factors for DCI:

• Fisher grade 3/4 (thick cisternal blood)
• Poor neurological grade (Hunt-Hess III-V)
• Age below 50 years (paradoxically higher risk)
• Smoking
• Hypertension
• Anemia (hemoglobin below 9 g/dL)

Monitoring for Vasospasm

Clinical monitoring:

• Neurological examination every 1-2 hours (ICU), every 4 hours (ward)
• New focal deficit (hemiparesis, aphasia) → urgent investigation
• GCS decline ≥2 points → urgent investigation

Transcranial Doppler (TCD) — Non-invasive bedside monitoring[36]

Technique:

• Insonation through temporal bone window
• Measure flow velocities in middle cerebral artery (MCA), anterior cerebral artery (ACA), internal carotid artery (ICA)

Interpretation:

• Mean MCA velocity:
  • below 120 cm/s: Low vasospasm risk
  • 120-200 cm/s: Moderate vasospasm
  • greater than 200 cm/s: Severe vasospasm
• Lindegaard ratio (MCA velocity / ICA velocity):
  • below 3: Normal or hyperemia
  • 3-6: Moderate vasospasm
  • greater than 6: Severe vasospasm
• Advantage of Lindegaard ratio: Distinguishes vasospasm from hyperemia (both cause high velocities)

Daily TCD monitoring recommended for Fisher 3/4 SAH patients.

CT perfusion (CTP) — Functional imaging

Indications:

• Suspected DCI (clinical deterioration + elevated TCD velocities)
• Distinguish vasospasm from other causes (rebleeding, hydrocephalus, seizure)

Parameters:

• Prolonged MTT (mean transit time): Suggests reduced flow
• Reduced CBF (cerebral blood flow): Ischemia
• Reduced CBV (cerebral blood volume): Infarction imminent
• MTT-CBV mismatch: Ischemic penumbra (salvageable tissue)

CT/MRI brain:

• Rule out rebleeding, hydrocephalus, hemorrhagic transformation
• Identify infarction (hypodensity on CT, DWI restriction on MRI)

Catheter angiography (DSA):

• Gold standard for vasospasm diagnosis
• Required if considering intra-arterial therapy
• Defines vasospasm location, severity, extent

Management of Vasospasm/DCI

Tiered approach:

Tier 1: Prevention (all SAH patients)

1. Nimodipine 60 mg q4h for 21 days (proven benefit, see above)
2. Euvolemia: CVP 8-12 mmHg, neutral fluid balance
3. Normothermia: Avoid fever greater than 38°C (paracetamol, cooling devices)
4. Avoid hypotension: Maintain SBP greater than 120 mmHg (after aneurysm secured)
5. Avoid anemia: Maintain hemoglobin greater than 80-90 g/L (transfuse if symptomatic)
6. Avoid hypoxia/hypercapnia: Target PaO₂ greater than 80 mmHg, PaCO₂ 35-40 mmHg

Tier 2: Induced Hypertension (first-line for DCI)

Indications:

• Clinical DCI (new deficit, GCS decline)
• Elevated TCD velocities (MCA greater than 200 cm/s, Lindegaard greater than 6)
• CT perfusion showing ischemia

Approach:[37]

• Increase SBP by 10-20 mmHg increments (target SBP 160-200 mmHg or MAP greater than 90-100 mmHg)
• Use vasopressors (NOT fluid boluses):
  • Norepinephrine infusion 0.05-0.5 mcg/kg/min (first-line)
  • Phenylephrine infusion 0.5-3 mcg/kg/min (pure alpha agonist)
  • Dopamine infusion 5-20 mcg/kg/min (if bradycardic)
• Monitor response: Clinical improvement (GCS, focal deficit), TCD velocities
• Continue until vasospasm window passes (typically day 14, then wean gradually)

Evidence: No high-quality RCT, but observational data shows 70% clinical improvement with induced hypertension.[38]

Monitoring during induced hypertension:

• Arterial line (continuous BP monitoring)
• Cardiac monitoring (arrhythmias, myocardial ischemia)
• Fluid balance (risk of pulmonary edema)
• Electrolytes (if using large fluid volumes)

Complications:

• Pulmonary edema (occurs in 15-20% with aggressive volume expansion)
• Myocardial ischemia (especially if pre-existing CAD)
• Cardiac arrhythmias

Tier 3: Endovascular Therapy (if medical management fails)

Indications:

• Severe DCI refractory to induced hypertension (no improvement after 1-2 hours)
• Progressive neurological deterioration despite maximal medical therapy

Options:

Intra-arterial vasodilators:[39]

• Verapamil: 5-10 mg via microcatheter into spastic artery (most common)
• Nimodipine: 2-4 mg intra-arterial
• Nicardipine: 10-20 mg intra-arterial
• Milrinone: 5-10 mg intra-arterial (phosphodiesterase-3 inhibitor)

Response:

• Immediate angiographic improvement in 70-90%
• Clinical improvement in 50-70%
• Duration: 12-24 hours (may require repeat sessions)

Balloon angioplasty:

• Indications: Proximal large vessel vasospasm (ICA, M1, A1, basilar)
• NOT suitable for distal vessels (risk of rupture)
• Technique: Inflate balloon to dilate artery
• Response: Permanent mechanical dilation (vs temporary with vasodilators)
• Improvement: 60-80% clinical improvement

Complications (both intra-arterial therapies):

• Arterial rupture (1-5%)
• Thromboembolism (2-3%)
• Groin hematoma (femoral access)

Failed therapies (NOT recommended):

• Clazosentan (endothelin receptor antagonist): CONSCIOUS-1 trial showed reduced vasospasm but NO improvement in clinical outcomes, increased pulmonary complications.[40]
• Statins: Meta-analyses show NO benefit (initial single-center studies not replicated).[41]
• Magnesium: MASH-2 trial showed NO benefit.[42]
• Routine triple-H therapy: No evidence, risk of pulmonary edema.

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Complications

Rebleeding

Epidemiology:

• 4% within first 24 hours
• 15-20% within 14 days if untreated
• 50% within 6 months if untreated
• 70-80% mortality per rebleeding episode[30]

Risk factors:

• Unsecured aneurysm (highest risk)
• Hypertension (SBP greater than 160 mmHg)
• Large aneurysm (greater than 10 mm)
• Sentinel headache (suggests unstable aneurysm)
• Poor neurological grade (Hunt-Hess IV-V)

Clinical presentation:

• Sudden neurological deterioration (GCS decline)
• Severe headache (if conscious)
• New focal deficit
• Loss of consciousness

Diagnosis:

• Urgent CT brain: New blood, increased blood volume, IVH extension

Management:

• URGENT aneurysm securing (coiling or clipping within hours if feasible)
• Blood pressure control (SBP below 140 mmHg until secured)
• Neurosurgery/interventional neuroradiology consultation immediately
• Prognosis: Very poor (70-80% mortality)

Hydrocephalus

Acute hydrocephalus (20-30%)

Pathophysiology: Obstructive hydrocephalus from blood blocking CSF pathways (aqueduct of Sylvius, fourth ventricle outlet foramina).

Clinical presentation:

• Decreased GCS (lethargy, stupor, coma)
• Headache, nausea, vomiting
• Upgaze palsy (Parinaud syndrome)
• Cushing's triad if severe (hypertension, bradycardia, irregular respirations)

Diagnosis:

• CT brain: Enlarged ventricles (temporal horns, third ventricle), periventricular hypodensity

Management:

• External ventricular drain (EVD):
  • "Indications: Acute hydrocephalus + GCS decline OR symptomatic"
  • Inserted into lateral ventricle (usually right frontal approach)
  • Drain CSF to target ICP below 20 mmHg
  • "Complications: Infection (ventriculitis 5-10%), hemorrhage, over-drainage"
• Serial lumbar punctures (if communicating hydrocephalus, aneurysm secured)

Delayed hydrocephalus (10-20%)

Pathophysiology: Communicating hydrocephalus from impaired CSF reabsorption (arachnoid granulations scarred by blood products).

Clinical presentation:

• Develops days to weeks after SAH
• Progressive gait instability, urinary incontinence, cognitive decline (classic NPH triad)
• May be subtle: "failure to improve" rather than acute deterioration

Diagnosis:

• CT/MRI: Ventriculomegaly (Evans ratio greater than 0.3)
• High-volume lumbar puncture (30-50 mL) → temporary clinical improvement suggests shunt will help

Management:

• Ventriculoperitoneal (VP) shunt:
  • Definitive treatment
  • Programmable valve preferred (adjust pressure non-invasively)
  • "Complications: Infection (5-10%), over-drainage (subdural hematoma), under-drainage"

Seizures

Incidence:

• At ictus: 8-18%
• Early (below 7 days): 10-15%
• Late (greater than 7 days): 5-10%
• Epilepsy (recurrent unprovoked seizures): 10-15% long-term

Risk factors:

• MCA aneurysms (cortical involvement)
• Intracerebral hemorrhage
• Infarction (especially cortical)
• Poor neurological grade

Management:

• Witnessed seizure: Benzodiazepines (lorazepam 0.1 mg/kg IV), load antiepileptic (levetiracetam 1000 mg IV or fosphenytoin 20 mg PE/kg)
• Prophylaxis (controversial):[28]
  • "Short-term (3-7 days): Levetiracetam 500 mg BD (fewer interactions than phenytoin)"
  • NOT recommended long-term (no proven benefit, phenytoin may worsen cognitive outcomes)
• Non-convulsive status epilepticus (NCSE): Consider in unexplained coma → continuous EEG monitoring

Hyponatremia

Incidence: 30-50% of SAH patients, typically days 3-10.

Mechanisms:

Cerebral salt wasting (CSW):

• Brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP) release
• Renal sodium loss → hypovolemia + hyponatremia
• Features: Low serum sodium, high urine sodium (greater than 100 mmol/L), high urine osmolality, hypovolemia (negative fluid balance, low CVP)

SIADH (syndrome of inappropriate ADH):

• Excessive ADH secretion
• Water retention → hyponatremia + euvolemia/hypervolemia
• Features: Low serum sodium, high urine sodium, high urine osmolality, euvolemia/hypervolemia (positive fluid balance, normal/high CVP)

Distinguishing CSW vs SIADH:

Clinical significance: Hyponatremia (Na below 135 mmol/L) associated with increased DCI risk, worse outcomes.

Management:

CSW (more common in SAH):

• Isotonic saline (0.9% NaCl) to restore volume
• Fludrocortisone 0.1-0.4 mg PO daily (mineralocorticoid, promotes sodium retention)
• Salt tablets 1-2 g TDS

SIADH:

• Fluid restriction (500-1000 mL/day)
• Hypertonic saline (3%) if severe (Na below 120 mmol/L or symptomatic)
• Correct slowly: Max 8-10 mmol/L rise in 24 hours (risk of osmotic demyelination syndrome)

Cardiac Complications

Neurogenic stunned myocardium (Takotsubo cardiomyopathy):

• Occurs in 10-30% of SAH patients
• Catecholamine surge → myocardial stunning (not ischemia)
• ECG changes: ST elevation/depression, T wave inversion, QTc prolongation
• Troponin elevation: 20-30% of SAH patients
• Echocardiography: Apical ballooning, reduced ejection fraction (30-40%)
• Management: Supportive, usually resolves in 1-2 weeks
• Significance: May complicate induced hypertension for vasospasm

Arrhythmias:

• Atrial fibrillation, ventricular ectopy, torsades de pointes (if QTc greater than 500 ms)
• Monitor ECG continuously in ICU

Pulmonary edema:

• Neurogenic (from catecholamine surge)
• Cardiogenic (if stunned myocardium)
• Iatrogenic (excessive fluid administration)

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Prognosis

Mortality and Functional Outcomes

Overall outcomes:[3]

• 30-day mortality: 30-45%
• 1-year mortality: 40-50%
• Good functional outcome (mRS 0-2): 30-50% at 6-12 months
• Moderate disability (mRS 3-4): 20-30%
• Severe disability or death (mRS 5-6): 30-40%

Predictors of poor outcome:

Clinical factors:

• Poor neurological grade (Hunt-Hess IV-V, WFNS IV-V)
• Age greater than 70 years
• Large aneurysm (greater than 10 mm)
• Posterior circulation aneurysm
• Rebleeding
• Delayed cerebral ischemia with infarction
• ICH or large IVH

Imaging factors:

• Fisher grade 3/4 (thick blood)
• Large IVH volume
• Hydrocephalus requiring shunt
• Cerebral infarction on CT/MRI

Complications:

• Medical complications (pneumonia, sepsis, cardiac events)
• Multiple organ dysfunction

Long-Term Outcomes

Cognitive impairment: 30-50% of survivors report memory, executive function, attention deficits.[43]

Depression and anxiety: 40-50% within first year.

Fatigue: 60-70% report persistent fatigue.

Return to work: 40-60% return to previous employment within 1 year.

Recurrent SAH: 1-2% per year with incidental unruptured aneurysms; below 0.5% per year if aneurysm fully treated.

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CICM SAQ Practice Questions

SAQ 1: Acute Management of SAH

Question: A 48-year-old woman presents to the Emergency Department with sudden onset severe headache, vomiting, and photophobia. GCS 14 (E4V4M6), BP 190/110 mmHg, HR 95 bpm. CT brain shows diffuse subarachnoid blood in basal cisterns and Sylvian fissures (Fisher grade 3). CTA identifies a 6mm anterior communicating artery aneurysm.

a) Outline your immediate management (first 6 hours). (40%) b) Describe your blood pressure management strategy before and after aneurysm securing. (30%) c) What pharmacological neuroprotection would you provide, including mechanism and evidence? (30%)

Model Answer:

a) Immediate management (40%)

ABCDE approach:

• Airway: GCS 14 adequate, monitor closely, position of comfort
• Breathing: High-flow oxygen (maintain SpO₂ greater than 94%), monitor respiratory rate
• Circulation:
  • Blood pressure control to prevent rebleeding (see part b)
  • Large-bore IV access × 2
  • Isotonic crystalloid (0.9% saline) to maintain euvolemia
• Disability:
  • Serial GCS monitoring (hourly initially)
  • Full neurological examination, document focal deficits
  • "Seizure prophylaxis: Levetiracetam 1000 mg IV loading, then 500 mg BD for 3-7 days"
• Exposure: Analgesia (paracetamol 1g IV, avoid opioids if possible to allow neuro assessment)

Specific SAH management:

• Nimodipine 60 mg PO/NG immediately, then every 4 hours for 21 days
• Neurosurgical/interventional neuroradiology consultation for urgent aneurysm securing
• ICU admission for close monitoring
• Prevent complications: DVT prophylaxis (mechanical only until aneurysm secured), stress ulcer prophylaxis

Investigations:

• Bloods: FBC, UEC, coagulation, troponin, ECG
• Repeat CT brain if neurological deterioration
• Plan for aneurysm securing within 24 hours

b) Blood pressure management strategy (30%)

Before aneurysm secured (minimize rebleeding risk):

• Target SBP below 160 mmHg
• First-line agents: IV labetalol 10-20 mg bolus, then infusion 0.5-2 mg/min OR nicardipine infusion 5 mg/h titrated
• Avoid excessive lowering (SBP below 120 mmHg) → may compromise cerebral perfusion
• Monitoring: Continuous arterial line BP monitoring

After aneurysm secured (optimize cerebral perfusion, prevent DCI):

• Permissive hypertension: Target SBP 140-160 mmHg (patient's baseline)
• Avoid hypotension (SBP below 100 mmHg)
• If vasospasm/DCI develops (days 4-14):
  • "Induced hypertension: Increase SBP to 160-200 mmHg using vasopressors (norepinephrine, phenylephrine)"
  • Titrate to clinical response (GCS, focal deficit improvement)

c) Pharmacological neuroprotection (30%)

Nimodipine 60 mg PO/NG every 4 hours for 21 days:

Mechanism:

• L-type calcium channel blocker (cerebral-selective)
• Neuroprotection through reduced calcium influx into neurons
• Prevents cell death from cortical spreading depolarizations, microvascular dysfunction
• NOT primarily a vasodilator (does not prevent angiographic vasospasm)

Evidence:

• British aneurysm nimodipine trial (1989): 554 patients randomized to nimodipine vs placebo
• Poor outcome reduced from 33% to 27% (absolute risk reduction 5.7%, NNT 7)
• Relative risk reduction 40%
• Cerebral infarction reduced from 33% to 22%
• No reduction in angiographic vasospasm, confirming neuroprotective mechanism

Administration:

• Oral or nasogastric tube (NOT intravenous: excessive hypotension, no benefit)
• Monitor blood pressure before each dose (hold if SBP below 100 mmHg)
• Duration: Full 21 days from SAH onset

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SAQ 2: Delayed Cerebral Ischemia and Vasospasm

Question: A 55-year-old man is day 7 post-SAH (Hunt-Hess II, Fisher 3, anterior communicating artery aneurysm coiled on day 1). He develops new right arm weakness and expressive aphasia. GCS declines from 15 to 13. BP 145/85 mmHg.

a) What is your differential diagnosis for neurological deterioration in this patient? (20%) b) Describe your approach to diagnosing delayed cerebral ischemia (DCI). (30%) c) Outline your stepwise management of DCI/vasospasm. (50%)

Model Answer:

a) Differential diagnosis (20%)

Vascular:

• Delayed cerebral ischemia (DCI) from vasospasm (most likely given day 7, Fisher 3)
• Rebleeding (less likely as aneurysm coiled, but check for coil compaction)
• Intracerebral hemorrhage (hemorrhagic transformation)

Structural:

• Hydrocephalus (acute or delayed)
• Cerebral edema with mass effect

Seizure-related:

• Seizure (focal or non-convulsive status epilepticus)
• Post-ictal Todd's paresis

Metabolic:

• Hyponatremia (SIADH or cerebral salt wasting common day 3-10)
• Hypoglycemia, other electrolyte disturbances

Infectious:

• Meningitis (especially if EVD in situ)

Other:

• Sedation (if receiving sedatives)
• Systemic infection (sepsis with encephalopathy)

b) Diagnostic approach to DCI (30%)

Immediate bedside:

• Neurological examination: Confirm new deficit (right arm weakness, expressive aphasia suggests left MCA territory)
• Blood glucose: Exclude hypoglycemia
• Electrolytes: Check sodium (hyponatremia common)

Imaging:

• Urgent CT brain non-contrast:
  • Rule out rebleeding, ICH, hemorrhagic transformation
  • Assess for hydrocephalus (ventricular size)
  • Look for hypodensity (infarction, though may not be visible acutely)
• CT perfusion:
  • Identify ischemic territory (prolonged MTT, reduced CBF)
  • MTT-CBV mismatch suggests salvageable penumbra
  • Guides decision for aggressive treatment

Transcranial Doppler (TCD):

• Measure MCA, ACA, ICA velocities
• MCA velocity greater than 200 cm/s suggests severe vasospasm
• Lindegaard ratio (MCA/ICA) greater than 6 confirms vasospasm (vs hyperemia)

Catheter angiography (DSA):

• Gold standard for vasospasm diagnosis
• Defines location, severity, extent
• Required if considering intra-arterial therapy

EEG (if considering seizure):

• To exclude non-convulsive status epilepticus

c) Stepwise management of DCI/vasospasm (50%)

Tier 1: Immediate interventions (all patients)

1. Optimize medical management:

   • Euvolemia: Ensure CVP 8-12 mmHg, give 250-500 mL crystalloid bolus
   • Nimodipine compliance: Ensure receiving 60 mg q4h (check NG tube position if applicable)
   • Normothermia: Treat fever greater than 38°C (paracetamol, cooling)
   • Avoid hypoxia: Supplemental O₂ to maintain SpO₂ greater than 94%
   • Avoid anemia: Transfuse if Hb below 80 g/L and symptomatic

2. Reverse exacerbating factors:

   • Correct hyponatremia if present
   • Avoid hypotension (stop antihypertensives if needed)

Tier 2: Induced hypertension (first-line for DCI)

Rationale: Increase cerebral perfusion pressure to ischemic territory

Approach:

• Vasopressor therapy (NOT fluid boluses):
  • Norepinephrine infusion 0.05-0.5 mcg/kg/min (first-line)
  • OR Phenylephrine 0.5-3 mcg/kg/min (pure alpha agonist)
• Target: Increase SBP by 10-20 mmHg increments
  • Aim for SBP 160-200 mmHg or MAP greater than 90-100 mmHg
• Titrate to clinical response:
  • Monitor GCS, focal deficit
  • Reassess every 15-30 minutes
  • If improvement → continue at that BP target
  • If no improvement after 1-2 hours → escalate to Tier 3

Monitoring:

• Arterial line (continuous BP)
• Cardiac monitor (arrhythmias, ischemia)
• Urine output (fluid balance)

Duration: Continue until vasospasm window passes (typically day 14), then wean gradually

Tier 3: Endovascular therapy (if Tier 2 fails)

Indications:

• Severe DCI refractory to induced hypertension (no improvement after 1-2 hours)
• Progressive neurological deterioration despite maximal medical therapy
• Angiographic severe vasospasm

Options:

Intra-arterial vasodilators:

• Verapamil 5-10 mg via microcatheter into spastic artery (most common)
• Immediate angiographic improvement 70-90%
• Clinical improvement 50-70%
• Duration 12-24 hours (may require repeat sessions)

Balloon angioplasty:

• For proximal large vessel vasospasm (ICA, M1, A1, basilar)
• NOT suitable for distal vessels (rupture risk)
• Permanent mechanical dilation (vs temporary with vasodilators)
• Clinical improvement 60-80%

Complications: Arterial rupture (1-5%), thromboembolism (2-3%)

Supportive:

• Continue induced hypertension
• Repeat TCD/CT perfusion to monitor response
• Neurosurgical involvement for ongoing care

---

CICM Viva Scenarios

Viva 1: Poor-Grade SAH Management

Scenario: A 62-year-old woman is brought to ED by ambulance. Bystanders report sudden collapse with loss of consciousness. On arrival: GCS 6 (E1V1M4), BP 210/120 mmHg, HR 105 bpm, pupils equal and reactive. CT brain shows extensive subarachnoid blood with IVH and acute hydrocephalus.

Expected Discussion Points:

Immediate management:

• ABCDE resuscitation: Airway protection (intubate, GCS 6), breathing (ventilate, avoid hypoxia), circulation (BP control)
• Intubation: RSI with hemodynamic control (fentanyl, propofol/etomidate, rocuronium), avoid hypertensive response
• Blood pressure control: Target SBP below 160 mmHg (labetalol or nicardipine infusion)
• ICP management: Head of bed 30°, avoid hypoxia/hypercapnia, consider EVD for hydrocephalus

Grading:

• Hunt-Hess V: Deep coma (GCS 6), moribund
• WFNS V: GCS 6
• Prognosis: 60-80% mortality (poor grade + IVH + hydrocephalus)

Hydrocephalus management:

• Indication for EVD: Acute hydrocephalus + coma (GCS 6)
• Insert urgently (right frontal approach into lateral ventricle)
• Drain to target ICP below 20 mmHg
• Monitor for improvement in GCS after EVD

Aneurysm identification and securing:

• CTA once stabilized
• Discuss with neurosurgery/interventional neuroradiology
• Coiling preferred for poor-grade SAH (less invasive than clipping)
• Timing: Within 24 hours if feasible after resuscitation

Prognostication and family discussion:

• Explain very poor prognosis (Hunt-Hess V: 70-90% mortality)
• Discuss goals of care, likelihood of severe disability even if survives
• Consider withdrawal of life-sustaining treatment if no improvement after aneurysm securing and EVD

---

Viva 2: Vasospasm Crisis

Scenario: ICU day 8 for 50-year-old man, Hunt-Hess II SAH, ACoA aneurysm coiled day 1, Fisher 3. Nurse reports patient suddenly developed right-sided weakness and difficulty speaking. You attend: GCS 13 (E4V3M6, expressive aphasia), right arm 3/5 power, BP 135/80 mmHg (baseline SBP 140-150). TCD from this morning showed MCA velocities 180 cm/s left, 120 cm/s right.

Expected Discussion Points:

Immediate assessment:

• Rapid neuro exam: Confirm new left MCA territory deficit (right arm weakness, expressive aphasia)
• Check blood glucose (exclude hypoglycemia)
• Review vitals, recent medications

Differential diagnosis:

• DCI from vasospasm (most likely: day 8, Fisher 3, elevated TCD)
• Rebleeding (less likely, aneurysm coiled)
• Seizure/post-ictal
• Hyponatremia
• Hydrocephalus

Urgent investigations:

• CT brain: Rule out rebleeding, ICH, hydrocephalus
• CT perfusion: Identify ischemic territory (left MCA), assess penumbra
• TCD: Repeat to assess current velocities (likely higher than morning)
• Electrolytes: Check sodium
• Blood glucose: Confirm euglycemia

Management escalation:

Tier 1 (optimize basics):

• Euvolemia: 500 mL crystalloid bolus
• Ensure nimodipine compliance
• Correct any hyponatremia

Tier 2 (induced hypertension):

• Start norepinephrine infusion 0.05 mcg/kg/min
• Target SBP 160-180 mmHg (increase by 20 mmHg from baseline)
• Assess response after 15-30 minutes:
  • If GCS improves, aphasia improves, weakness improves → continue
  • If no improvement → increase SBP to 180-200 mmHg
• Insert arterial line for continuous BP monitoring

Tier 3 (if no improvement after 1-2 hours):

• Contact interventional neuroradiology for catheter angiography
• Confirm vasospasm, assess severity and distribution
• Intra-arterial verapamil 5-10 mg into left MCA via microcatheter
• Consider balloon angioplasty if proximal M1 segment vasospasm

Ongoing monitoring:

• Serial GCS and neuro exams (hourly)
• Repeat TCD daily
• CT brain if further deterioration
• Continue induced hypertension until day 14, then wean

---

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