Subarachnoid hemorrhageMANAGEMENT

NEUROLOGICAL PRESENTATIONS · 12 SECTIONS

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450 items

☷ Legend

01Approach to the Critical Patient/attcp51

Immediate priorities

›Time-critical stabilization

›Airway protection triggers

›GCS 8 or less

›Recurrent vomiting with aspiration risk

›Hypoventilation

›Refractory agitation preventing imaging

›Breathing targets

›Oxygen saturation 94% or higher

›End-tidal CO2 35 to 40 mmHg if ventilated

›Circulation priorities

›Two large-bore IV access

›Continuous ECG monitoring

›Frequent neurologic reassessment trigger for resuscitation bay

›Early high-risk identification

›Aneurysmal SAH concern

›Thunderclap headache peak intensity under 1 minute

›Witnessed collapse or syncope

›New seizure at onset

›Meningismus

›Focal neurologic deficit

›Sentinel headache concern

›Sudden severe headache days to weeks prior

›Similar episode with spontaneous resolution

Hemodynamic goals

›Physiologic targets

›Systolic blood pressure target under 160 mmHg before aneurysm secured

›Lower targets if ongoing bleeding concern and no ischemia concern

›Avoid rapid large drops in chronic hypertension

›Temperature under 38.0 C

›Treat fever as secondary brain injury risk

›Serum glucose 7.8 to 10.0 mmol/l

›Avoid hypoglycemia

›Euvolemia

›Avoid hypotonic fluids

›Avoid routine hypervolemia

Early consultation and pathway

›Neurovascular activation

›Neurosurgery early notification

›Hydrocephalus concern

›Declining mental status

›Need for external ventricular drain

›Interventional neuroradiology or endovascular team notification

›CTA positive aneurysm

›High suspicion with negative initial imaging

›ICU disposition planning

›Any confirmed SAH

›Any depressed level of consciousness

›Need for titratable BP agents

›Transfer triggers

›No neurosurgery or endovascular capability

›Transfer after initial stabilization and imaging if feasible

›BP control during transport

›Airway secured prior to transport if unstable

02History/hx41

Symptom pattern

›Headache phenotype

›Thunderclap onset

›Peak intensity under 1 minute

›Worst headache of life descriptor

›Timing

›Exact onset time for CT interpretation window

›Duration and persistence

›Associated symptoms

›Syncope or near-syncope

›Neck pain or stiffness

›Photophobia

›Nausea or vomiting

›New seizure

›Prodrome and warning leaks

›Sentinel headache

›Sudden severe headache in prior 1 to 4 weeks

›Different from usual migraine pattern

Risk factors and triggers

›Vascular and genetic risk

›Known intracranial aneurysm

›Family history of aneurysm or SAH

›Polycystic kidney disease

›Connective tissue disorder history

›Ehlers-Danlos vascular type

›Marfan syndrome

›Acquired risk

›Hypertension

›Tobacco use

›Cocaine or amphetamine exposure

›Heavy alcohol use or binge

›Antithrombotic exposure

›Anticoagulant type and last dose time

›Antiplatelet agents

›Known bleeding disorder

Context and competing explanations

›Trauma context

›Head strike

›High-risk mechanism

›Anticoagulation with trauma

›Alternative headache history

›Known migraine pattern and typical aura

›Prior thunderclap episodes

›Exertional or sexual headache history

03Physical Exam/exam28

Neurologic and meningeal findings

›Neurologic screen

›Level of consciousness

›GCS trend

›New confusion or agitation

›Focal deficits

›Cranial nerve palsy

›Motor asymmetry

›Aphasia

›Neglect

›Seizure activity

›Ongoing convulsions

›Postictal state

›Meningeal irritation

›Nuchal rigidity

›Photophobia

›Pain with neck flexion

General and cardiopulmonary

›Vital signs pattern

›Hypertension severity

›Bradycardia with hypertension

›Fever

›Cardiac findings

›Arrhythmia

›Pulmonary edema signs

›Stress cardiomyopathy concern

PITFALLS

›Missed SAH patterns

›Normal neurologic exam does not exclude SAH

›Symptom improvement does not exclude aneurysmal leak

›Migraine label with atypical thunderclap onset

04Differential Diagnosis/ddx23

Life-threatening causes of thunderclap headache

›High-risk neurologic diagnoses

›Subarachnoid hemorrhage

›ICD-10 I60.0 to I60.9

›SNOMED CT subarachnoid hemorrhage

›Intracerebral hemorrhage

›Cervical artery dissection

›Cerebral venous sinus thrombosis

›Reversible cerebral vasoconstriction syndrome

›Pituitary apoplexy

›Meningitis or encephalitis

›Acute ischemic stroke with headache

›High-risk systemic diagnoses

›Hypertensive emergency with encephalopathy

›Carbon monoxide toxicity

›Acute angle-closure glaucoma

Mimics and lower-risk causes

›Primary headache disorders

›Migraine

›Cluster headache

›Primary thunderclap headache

›Secondary benign causes

›Viral syndrome headache

›Sinusitis with severe pain

›Medication overuse headache

05Laboratory Tests/lt24

Baseline tests for SAH pathway

›Initial labs

›Complete blood count for anemia and platelet count

›Thrombocytopenia threshold for procedure planning under 100 x 10^9/l

›Electrolytes for hyponatremia risk

›Serum sodium trend for cerebral salt wasting concern

›Creatinine for contrast imaging safety

›CTA feasibility

›INR and aPTT for anticoagulation effect

›Reversal planning if elevated

›Type and screen

›Potential neurosurgical intervention

›Massive transfusion unlikely but peri-procedural planning

Cardiac and endocrine adjuncts

›ECG and troponin consideration labs

›Troponin for neurogenic myocardial injury concern

›Prognostic association with worse outcomes

›Pregnancy testing

›All patients with pregnancy potential prior to imaging and meds

Lumbar puncture adjunct labs

›Cerebrospinal fluid studies if LP performed

›RBC count in serial tubes

›Lack of reliable exclusion based on tube clearing alone

›Xanthochromia testing if available

›Supports SAH when present

›Opening pressure

›Elevated pressure supports alternative diagnoses like CVST

06Diagnostic Tests/dt65

Scoring Systems

›Clinical decision tools

›Ottawa SAH rule for alert headache patients

›Inclusion

›New severe nontraumatic headache

›Peak within 1 hour

›Normal neurologic exam

›High-risk features

›Age 40 years or older

›Neck pain or stiffness

›Witnessed loss of consciousness

›Onset during exertion

›Thunderclap headache

›Limited neck flexion on exam

›Use case

›Rule-out aid for selecting imaging

›Not a standalone exclusion strategy

›Severity grading after diagnosis

›Hunt and Hess grade

›Clinical grade for prognosis and communication

›WFNS grade

›GCS-based stratification

›Fisher or modified Fisher grade

›CT blood burden for vasospasm risk

MRI

›MRI roles

›Delayed presentation with negative CT and nondiagnostic LP

›FLAIR and susceptibility sequences for blood products

›Alternative diagnosis evaluation

›CVST evaluation with MRV

›Dissection evaluation with MRA

›Limitations

›Limited availability in unstable patients

›Time and monitoring constraints in acute resuscitation

›Noncontrast CT head

›First-line test for suspected SAH

›Highest yield early after onset

›Timing dependence

›Highest sensitivity within 6 hours in modern multi-detector CT with expert interpretation

›Sensitivity decreases with time from onset

›Interpretation targets

›Basal cistern blood

›Sylvian fissure blood

›Intraventricular hemorrhage

›Hydrocephalus

›CT angiography head and neck

›Aneurysm detection after SAH confirmation

›Aneurysm size and morphology

›Multiple aneurysms possibility

›Alternative diagnosis support

›RCVS pattern

›Dissection evaluation

›ACEP acute headache guidance

›Normal noncontrast CT within 6 hours in neurologically normal patient can exclude SAH in appropriate setting

›ACEP Level B recommendation

›If still at risk after negative CT

›LP or CTA as next step

›ACEP Level C recommendation

Ultrasound (or US)

›Point-of-care ultrasound adjuncts

›Cardiac POCUS

›Stress cardiomyopathy pattern

›Pulmonary edema association

›Optic nerve sheath diameter

›Elevated ICP screening adjunct

›Not definitive for SAH diagnosis

›IVC assessment

›Volume status support for euvolemia goals

07Disposition/dispo18

Level of care

›Admission requirements

›All confirmed SAH

›ICU or neuro-ICU level care

›High suspicion pending workup

›Ongoing severe headache with abnormal imaging plan

›Need for serial neuro checks

›Monitoring needs

›Frequent neurologic checks

›Strict BP control with IV titratable agents

›Airway or ventilation support

›Hydrocephalus concern

Transfer and definitive management site

›Transfer criteria

›Need for aneurysm securing

›Endovascular coiling or surgical clipping capability

›Need for EVD placement capability

›Timing principles

›Early aneurysm securing to prevent rebleeding

›Avoid prolonged ED boarding without neurocritical monitoring

08Treatment/t104

Immediate measures

›Supportive care bundle

›Head of bed 30 degrees

›Aspiration reduction

›ICP reduction support

›Analgesia and antiemesis

›Avoid severe pain-driven hypertension

›Avoid vomiting-driven ICP spikes

›Stool softener consideration

›Avoid Valsalva

›Normothermia strategy

›Acetaminophen

›Surface cooling if refractory

Blood pressure management before aneurysm secured

›IV antihypertensives

›Nicardipine infusion

›Initiate 5 mg/hour

›Titration 2.5 mg/hour every 5 to 15 minutes

›Maximum 15 mg/hour

›Monitoring

›Continuous BP

›Hypotension avoidance

›Clevidipine infusion

›Initiate 1 to 2 mg/hour

›Titration doubling every 90 seconds to 3 minutes initially

›Then titration small increments every 5 to 10 minutes

›Contraindications

›Allergy to egg or soy products

›Defective lipid metabolism syndrome

›Labetalol IV bolus

›Initiate 10 to 20 mg slow IV

›Repeat 10 to 20 mg every 10 minutes as needed

›Typical cumulative maximum 300 mg

›Contraindications

›Severe asthma with bronchospasm

›Bradycardia with hypotension

Rebleeding prevention and aneurysm securing pathway

›Antifibrinolytic short-course in select patients

›Indication

›High rebleeding risk with delayed aneurysm securing

›Tranexamic acid IV example regimen

›Initiate 1 g IV

›Then 1 g IV every 6 to 8 hours

›Stop once aneurysm secured

›Risks

›Thromboembolism concern

›DCI risk concern

›Definitive aneurysm management

›Endovascular coiling

›Preferred in many anatomies and older patients

›Surgical clipping

›Consider for certain aneurysm morphologies

›Guideline alignment

›Early aneurysm securing recommended in aneurysmal SAH

›Class I recommendation in major society guidance

Delayed cerebral ischemia and vasospasm prevention

›Nimodipine

›Oral regimen

›Initiate 60 mg PO every 4 hours

›Duration 21 days

›Dose reduction strategy if hypotension

›Evidence

›Improves neurologic outcomes after aneurysmal SAH

›Class I recommendation in major society guidance

›Volume strategy

›Euvolemia target

›Isotonic crystalloids

›Avoid prophylactic hypervolemia

Hydrocephalus and elevated ICP

›Acute hydrocephalus management

›External ventricular drain

›Neurosurgery placement

›CSF diversion with ICP monitoring

›Temporizing measures if herniation concern

›Hypertonic saline bolus protocol per institutional policy

›Avoid hypotonic fluids

Seizure management

›Acute seizure treatment

›Benzodiazepine first-line

›Lorazepam IV 0.1 mg/kg

›Maximum 4 mg per dose

›Repeat once if needed

›Second-line antiseizure medication

›Levetiracetam IV 60 mg/kg

›Maximum 4.5 g

›Prophylaxis considerations

›Short-course prophylaxis in high-risk features

›Intraparenchymal hematoma

›Cortical involvement

›Early seizure

›Routine long-course prophylaxis avoidance

›Adverse effect and limited benefit concern

Antithrombotic reversal and hemostasis

›Warfarin reversal

›4-factor PCC

›Dose per INR and weight per local protocol

›Vitamin K IV

›5 to 10 mg IV

›Dabigatran reversal

›Idarucizumab

›5 g IV total

›Two 2.5 g doses

›Factor Xa inhibitor reversal

›Andexanet alfa if available

›Dosing based on agent and last dose timing

›4-factor PCC alternative

›Institutional protocol dosing

›Platelet issues

›Platelet transfusion considerations

›Severe thrombocytopenia with procedure planned

›Antiplatelet reversal strategy individualized with neurosurgery

09Special Populations/sp29

Pregnancy

›Pregnancy-specific considerations

›Differential emphasis

›Preeclampsia and eclampsia

›CVST risk increase

›Imaging approach

›Noncontrast CT head acceptable when clinically indicated

›Shielding and dose minimization principles

›Medication safety

›Nimodipine risk-benefit discussion with obstetrics

›Labetalol and hydralazine commonly used for BP control

›Consultation

›Obstetrics and maternal-fetal medicine early involvement

Geriatric

›Older adult considerations

›Higher baseline aneurysm prevalence

›Higher procedural risk

›Increased susceptibility to hypotension from antihypertensives

›Delirium risk with sedatives and opioids

›Goals of care discussions early when poor-grade SAH

Pediatrics

›Pediatric SAH features

›Lower aneurysmal proportion than adults

›AVM and trauma proportion higher

›Dosing approach

›Weight-based medication dosing

›Benzodiazepines

›Levetiracetam

›BP targets individualized with pediatric critical care

›Imaging considerations

›Radiation minimization

›Early neurosurgery and pediatric neurocritical care involvement

10Background/b32

Epidemiology

›Burden and outcomes

›Aneurysmal SAH is a cause of sudden severe headache with high morbidity

›Early rebleeding risk highest in first 24 hours without aneurysm securing

›Vasospasm and delayed cerebral ischemia common contributors to poor outcome

›Risk factor associations

›Hypertension association with aneurysm formation and rupture

›Tobacco use association with aneurysm rupture risk

›Family history association with aneurysm prevalence

Pathophysiology

›Bleeding source categories

›Aneurysmal rupture into subarachnoid space

›Traumatic SAH

›ICD-10 S06.6X

›Nonaneurysmal perimesencephalic hemorrhage

›AVM or dural AV fistula hemorrhage

›Secondary injury mechanisms

›Global cerebral edema

›Hydrocephalus from impaired CSF resorption

›Vasospasm and microthrombosis

›Cortical spreading depolarizations

›Neurogenic cardiac injury and pulmonary edema

Therapeutic Considerations

›Time-dependent priorities

›Early aneurysm securing to prevent rebleeding

›Nimodipine to improve neurologic outcomes

›Euvolemia to support cerebral perfusion

›BP strategy logic

›High BP associated with rebleeding risk

›Excessive lowering risks cerebral hypoperfusion

›DCI management concepts

›Clinical monitoring for new deficits

›Rescue strategies in ICU settings

›Induced hypertension after aneurysm secured

›Endovascular therapy for refractory vasospasm

11Patient Discharge Instructions/pdi19

copy discharge instructions

›Discharge instructions for negative SAH evaluation

›Return now for red flags

›Sudden severe headache recurrence

›Fainting or near-fainting

›New weakness

›New numbness

›New trouble speaking

›New vision changes

›New seizure

›Persistent vomiting

›Fever with stiff neck

›Confusion or worsening drowsiness

›Activity

›Avoid heavy exertion until follow-up if symptoms not fully resolved

›Medications

›Avoid new anticoagulants unless prescribed by clinician

›Follow-up

›Primary care or neurology follow-up within 48 to 72 hours if headache persists

›Immediate follow-up for recurrent thunderclap headache

12References/r16

Clinical guidelines and key evidence

›Major society guideline sources

›American Heart Association and American Stroke Association guideline for aneurysmal subarachnoid hemorrhage management

›Recommendations for early aneurysm securing

›Recommendations for nimodipine

›Recommendations for DCI monitoring and treatment

›Neurocritical care society guidance for SAH management principles

›ICU monitoring standards

›EVD and hydrocephalus management principles

›Emergency medicine clinical policy sources

›ACEP clinical policy on acute headache

›Noncontrast CT within 6 hours in neurologically normal patient as exclusion strategy

›Next-step testing options after negative CT when risk persists

›Decision tool evidence

›Ottawa SAH rule derivation and validation studies

›High sensitivity in eligible populations

›Limited specificity requiring clinical judgment

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Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

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