Study guide
10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke
ABIM Internal Medicine Exam
Track your progress as you read
Finished sections get a check mark.
1 Chapter 0: The ABIM Exam, Blueprint & Study Strategy
0.1 Exam Format, Question Types & the 2026 Blueprint 0.2 Eligibility, Registration, Fees & Exam-Day Logistics 0.3 Scoring, the Passing Standard & Score Reports 0.4 Building a Blueprint-Weighted Study Plan
2 Chapter 1: Cardiovascular Disease (14% of Exam)
1.1 Ischemic Heart Disease & Acute Coronary Syndromes 1.2 Antithrombotic Therapy, Secondary Prevention & Mechanical Complications of MI 1.3 Atrial Fibrillation, Atrial Flutter & Stroke Prevention 1.4 Supraventricular Tachycardias, Ventricular Arrhythmias & Bradycardias 1.5 Heart Failure: Classification, Staging & Guideline-Directed Medical Therapy 1.6 Device Therapy, HFpEF & the Cardiomyopathies 1.7 Valvular Heart Disease & Endocarditis Prophylaxis 1.8 Pericardial Disease & Acute Aortic Syndromes 1.9 Hypertension: Classification, Diagnosis & Secondary Causes 1.10 Hypertensive Crises & Dyslipidemia 1.11 Adult Congenital Heart Disease & Coarctation of the Aorta 1.12 Syncope: Reflex, Orthostatic & Cardiac Causes 1.13 Cardiac Physical Examination, Murmurs & Antithrombotic Selection
3 Chapter 2: Endocrinology, Diabetes & Metabolism (9% of Exam)
2.1 Diabetes Mellitus: Diagnosis, Glycemic Targets & Pharmacotherapy 2.2 Insulin Therapy, Hyperglycemic Emergencies & Chronic Complications 2.3 Thyroid Function Testing & Hypothyroidism 2.4 Thyrotoxicosis, Thyroid Storm & Thyroid Nodules 2.5 Adrenal & Pituitary Disorders 2.6 Hypercalcemia, Hypocalcemia & Disorders of Mineral Metabolism 2.7 Osteoporosis & Paget Disease of Bone 2.8 Ovarian, Testicular & Reproductive Endocrine Disorders 2.9 Hypoglycemia, Endocrine Tumors, Polyglandular Syndromes & Severe Hypertriglyceridemia
4 Chapter 3: Gastroenterology & Hepatology (9% of Exam)
3.1 Esophageal Disease 3.2 Stomach & Duodenal Disease and Gastrointestinal Hemorrhage 3.3 Inflammatory Bowel Disease 3.4 Celiac Disease & Irritable Bowel Syndrome 3.5 Diverticular Disease & Colorectal Cancer Screening 3.6 Viral Hepatitis, Steatotic & Alcohol-Associated Liver Disease 3.7 Cirrhosis & the Complications of Portal Hypertension 3.8 Acute Pancreatitis 3.9 Chronic Pancreatitis & Biliary Tract Disease 3.10 Inherited, Autoimmune & Drug-Induced Liver Disease 3.11 Small Intestinal Disease, Ischemia & Gastrointestinal Complications of HIV
5 Chapter 4: Infectious Disease (9% of Exam)
4.1 Lower Respiratory Tract Infections & Sepsis Syndromes 4.2 Viral Respiratory Pathogens & Tuberculosis 4.3 Central Nervous System Infections 4.4 Skin, Soft Tissue, Bone & Joint Infections 4.5 Infective Endocarditis & Cardiovascular Infection 4.6 Clostridioides difficile & Catheter-Related Bloodstream Infection 4.7 HIV Diagnosis, Antiretroviral Therapy & Prevention 4.8 Opportunistic Infections & Sexually Transmitted Infections 4.9 Fever of Unknown Origin, Neutropenic Fever & Toxic Shock 4.10 Travel-Related Illness, Vector-Borne Disease & Outbreaks 4.11 Infection Prevention, Nosocomial Infection & Postexposure Prophylaxis 4.12 Rheumatic Fever, Poststreptococcal Disease, Enteric & Hepatic Infections
6 Chapter 5: Pulmonary Disease (9% of Exam)
5.1 COPD: Diagnosis, GOLD Classification & Initial Pharmacotherapy 5.2 Interventions That Reduce COPD Mortality & Exacerbation Management 5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus 5.4 Interstitial Lung Disease & Idiopathic Pulmonary Fibrosis 5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease 5.6 Pulmonary Embolism: Diagnosis, Risk Stratification & Anticoagulation 5.7 Pulmonary Hypertension & Sleep-Disordered Breathing 5.8 Acute Respiratory Distress Syndrome & Mechanical Ventilation 5.9 Pleural Disease, Empyema & Pneumothorax 5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease 5.11 Evaluation of Cough, Dyspnea, Hemoptysis & the Solitary Pulmonary Nodule
7 Chapter 6: Rheumatology & Orthopedics (9% of Exam)
6.1 Rheumatoid Arthritis: Diagnosis & Systemic Manifestations 6.2 Antirheumatic Pharmacotherapy & the Spondyloarthropathies 6.3 Gout: Pathophysiology & Acute Management 6.4 Urate-Lowering Therapy & Calcium Pyrophosphate Deposition Disease 6.5 Osteoarthritis 6.6 Systemic Lupus Erythematosus 6.7 Systemic Sclerosis, Sjogren Syndrome & Inflammatory Myopathies 6.8 The Vasculitides 6.9 Regional Musculoskeletal Syndromes, Back Pain & Sports Injuries 6.10 Other Primary Rheumatic Disorders & Mixed Connective Tissue Disease 6.11 Osteonecrosis & Metabolic Bone Disease
8 Chapter 7: Hematology (6% of Exam)
7.1 Approach to Anemia & the Microcytic Anemias 7.2 Macrocytic, Normocytic & Hemolytic Anemias 7.3 Hemoglobinopathies, Thalassemias & Paroxysmal Nocturnal Hemoglobinuria 7.4 Platelet Disorders, Thrombocytopenia & the Bleeding Patient 7.5 Coagulation Factor Disorders, Thrombophilia & Anticoagulant Reversal 7.6 Acute Leukemias, Chronic Leukemias & Myeloproliferative Neoplasms 7.7 Lymphomas & Plasma Cell Disorders 7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria 7.9 Transfusion Medicine & Late Complications of Transplantation
9 Chapter 8: Medical Oncology (6% of Exam)
8.1 Breast, Lung, Colorectal & Prostate Cancer 8.2 Oncologic Emergencies 8.3 Genitourinary & Gynecologic Malignancies 8.4 Head and Neck, Bone & Soft Tissue Cancer and Cancer of Unknown Primary 8.5 Complications of Cancer & Its Treatment 8.6 Cancer Prevention, Survivorship & Psychosocial Care
10 Chapter 9: Nephrology & Urology (6% of Exam)
9.1 Acute Kidney Injury: Staging, Etiology & Urine Microscopy 9.2 Glomerular Disorders & Nephrotic Syndrome 9.3 Nephritic Syndromes, RPGN & Indications for Renal Replacement Therapy 9.4 Chronic Kidney Disease: Staging & Progression Retardation 9.5 Complications of Chronic Kidney Disease: Anemia, CKD-MBD & Acidosis 9.6 Hyponatremia, Hypernatremia & Water Balance 9.7 Potassium Disorders & Systematic Acid-Base Analysis 9.8 Renal Tubular Acidosis & Nephrolithiasis 9.9 Prostate Disorders, Urinary Incontinence & Other Urologic Conditions 9.10 Cystic Kidney Disease, Obstructive Uropathy, Tubulointerstitial Disease & Hematuria
11 Chapter 10: Neurology (4% of Exam)
10.1 Acute Ischemic Stroke: Syndromes & Reperfusion 10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke 10.3 Headache & Facial Pain 10.4 Seizures, Epilepsy & Movement Disorders 10.5 Multiple Sclerosis & Neuromuscular Junction Disorders 10.6 Motor Neuron Disease & Acute Peripheral Neuropathy 10.7 Cranial Neuropathies & Neuro-Ophthalmology 10.8 Peripheral Neuropathies, CNS Tumors & Other Neurologic Disorders
12 Chapter 11: Psychiatry & Behavioral Health (4% of Exam)
11.1 Major Depressive Disorder & Medical Mimics 11.2 Antidepressant Pharmacotherapy & Treatment-Resistant Depression 11.3 Bipolar Disorder, Mood Stabilizers & Lithium Toxicity 11.4 Anxiety, Stress-Related & Obsessive-Compulsive Disorders 11.5 Alcohol Use Disorder & Withdrawal 11.6 Pharmacotherapy for Alcohol & Opioid Use Disorder 11.7 Toxidromes, Psychiatric Emergencies & Suicide Risk Assessment 11.8 Psychotic, Somatic Symptom, Factitious & Personality Disorders 11.9 Eating Disorders, Sleep Disorders & Sexual Health
13 Chapter 12: Dermatology (3% of Exam)
12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses 12.2 Acne, Rosacea & Cutaneous Infections 12.3 Herpes Zoster & Autoimmune Blistering Diseases 12.4 Nodules, Tumors & Cutaneous Oncology 12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions 12.6 Pigment Disorders, Alopecia, Nail Disease & Photosensitivity 12.7 Vascular Dermatoses, Environmental Injury & Cutaneous Signs of Systemic Disease
14 Chapter 13: Obstetrics & Gynecology / Women's Health (3% of Exam)
13.1 Contraception, Preconception Care & Teratogenicity 13.2 Hypertensive Disorders of Pregnancy & Gestational Diabetes 13.3 Thyroid Disease & Venous Thromboembolism in Pregnancy 13.4 Menopause & Menopausal Hormone Therapy 13.5 Abnormal Uterine Bleeding, Endometrial Disease & Gynecologic Cancer Screening 13.6 Breast Disorders & Diseases of the Vulva and Vagina 13.7 Menstrual Disorders, Fibroids, Endometriosis & Early Pregnancy Complications
15 Chapter 14: Geriatric Syndromes (3% of Exam)
14.1 Comprehensive Geriatric Assessment & Frailty 14.2 Falls, Gait Assessment & Polypharmacy 14.3 Urinary Incontinence & Pressure Injuries in Older Adults 14.4 Mild Cognitive Impairment, Dementia & Its Subtypes 14.5 Delirium & the Pharmacotherapy of Cognitive Disorders 14.6 Palliative Care, Hospice & Advance Care Planning 14.7 Chronic Wounds, Nutrition, Swallowing, Constipation & Hip Fracture 14.8 Sensory Impairment, Dizziness, Elder Mistreatment & Care Settings
16 Chapter 15: Allergy & Immunology (2% of Exam)
15.1 Anaphylaxis: Recognition & Emergency Management 15.2 Urticaria & Angioedema 15.3 Drug Allergy, Desensitization & Adult Immunodeficiency 15.4 Food Allergy, Insect Venom Hypersensitivity, Serum Sickness & Contrast Reactions 15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders
17 Chapter 16: Preventive Medicine, Immunization & Clinical Epidemiology
16.1 The USPSTF Framework & Evidence-Based Cancer Screening 16.2 Cardiovascular & Metabolic Screening and Primary Prevention 16.3 Adult Immunization & Vaccines in Special Populations 16.4 Clinical Epidemiology, Biostatistics & Study Design
18 Chapter 17: Miscellaneous - Ethics, Patient Safety & Quality Improvement (2% of Exam)
17.1 Principles of Bioethics & Decisional Capacity 17.2 Informed Consent, Treatment Refusal & Special Scenarios 17.3 Surrogate Decision-Making, Advance Directives & Confidentiality 17.4 Patient Safety Science, Medical Error & Diagnostic Reasoning 17.5 Quality Improvement Methods, Health Disparities & Health Equity
19 Chapter 18: Perioperative Medicine & Medical Consultation
18.1 Preoperative Cardiovascular Risk Assessment 18.2 Preoperative Pulmonary Risk & Perioperative Medication Management 18.3 Perioperative Anticoagulation, Bridging & Postoperative Complications
20 Chapter 19: Ophthalmology (1% of Exam)
19.1 The Acute Red Eye & Ophthalmic Emergencies 19.2 Painless Vision Loss & Chronic Ophthalmic Disease 19.3 Uveitis, Scleritis & Orbital Disease
21 Chapter 20: Otolaryngology & Dental Medicine (1% of Exam)
20.1 Dizziness, Vertigo & Epistaxis 20.2 Ear Disorders, Hearing Loss & Upper Respiratory Infections 20.3 Oral Cavity, Salivary Gland, Laryngeal & Taste and Smell Disorders
10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke
Key Takeaways Explain This Topic AI
Transient ischemic attack requires urgent evaluation because early stroke risk is concentrated in the first 48 hours.
Short-term dual antiplatelet therapy after minor stroke or high-risk transient ischemic attack reduces recurrence and is then narrowed to a single agent.
Four-factor prothrombin complex concentrate with vitamin K is the fastest reversal for warfarin-associated intracerebral hemorrhage.
A negative non-contrast computed tomography does not exclude subarachnoid hemorrhage beyond the first hours, so lumbar puncture or vascular imaging is required.
Nimodipine reduces poor outcome from delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage and is given to all such patients.
Last updated: August 2026
1. Post-Stroke Secondary Prevention & Antithrombotic Selection
Clinical Stroke Subtype First-Line Antithrombotic Strategy Clinical Trial Evidence & Rules Ancillary Pharmacotherapy & Targets
Minor Non-Cardioembolic Ischemic Stroke (NIHSS <=3) OR High-Risk TIA (ABCD2 >=4) Dual Antiplatelet Therapy (DAPT): Aspirin (162-325 mg load, then 81 mg daily) + Clopidogrel (300-600 mg load, then 75 mg daily) initiated within 24 hours CHANCE and POINT Trials: Continue DAPT for exactly 21 days , then transition to single antiplatelet therapy (Aspirin or Clopidogrel) indefinitely. (Do not continue DAPT beyond 21-90 days due to excess major hemorrhage without added ischemic benefit) High-intensity statin ( Atorvastatin 80 mg daily per SPARCL trial; target LDL-C <70 mg/dL); Blood pressure goal <130/80 mmHg long-term
Moderate-to-Severe Non-Cardioembolic Stroke (NIHSS >=4) Single Antiplatelet Therapy: Aspirin 81-325 mg daily monotherapy (or Clopidogrel 75 mg daily monotherapy) initiated within 24-48 hours Standard monotherapy. If patient was treated with IV thrombolysis, delay antiplatelet therapy for 24 hours post-infusion until follow-up CT rules out hemorrhagic transformation High-intensity statin; Glycemic control (HbA1c <7.0%); Smoking cessation
Cardioembolic Stroke (Atrial Fibrillation / Flutter) Direct Oral Anticoagulants (DOACs): Apixaban 5 mg BID, Rivaroxaban 20 mg daily, or Dabigatran 150 mg BID (preferred over Warfarin) "1-3-6-12 Day Rule" for DOAC Initiation: ; - Day 1: Transient Ischemic Attack (TIA); - Day 3: Minor stroke (small non-disabling infarct); - Day 6: Moderate stroke (non-disabling, small-to-medium core); - Day 12 to 14: Large territorial cortical infarction (repeat CT/MRI at day 12-14 to exclude hemorrhagic conversion prior to starting DOAC) DOAC dose adjustments for age >=80, weight <=60 kg, or serum Cr >=1.5 mg/dL (Apixaban: 2.5 mg BID if >=2 criteria met)
Symptomatic Severe Extracranial Carotid Stenosis (70-99%) Carotid Endarterectomy (CEA) (or Carotid Artery Stenting [CAS] in high surgical risk anatomy) NASCET Trial: CEA provides maximal stroke risk reduction when performed within <=14 days of minor stroke or TIA in patients with non-disabling deficits Single antiplatelet + high-intensity statin prior to and following revascularization
- 2. Transient Ischemic Attack (TIA) & The ABCD2 Risk Score
- Modern Tissue-Based Definition of TIA
A Transient Ischemic Attack (TIA) is defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia without acute infarction on diffusion-weighted imaging (DWI) MRI . The traditional arbitrary time limit of <24 hours has been superseded by this tissue-based definition: any persistent DWI hyperintensity confirms acute ischemic stroke regardless of symptom duration.
The ABCD2 Risk Stratification Score
The ABCD2 score predicts the 48-hour and 7-day risk of subsequent completed ischemic stroke following a TIA:
- A — Age: >=60 years = 1 point
- B — Blood Pressure: Systolic BP >=140 mmHg OR Diastolic BP >=90 mmHg on initial evaluation = 1 point
C — Clinical Features:
- Unilateral motor weakness (with or without speech impairment) = 2 points
- Speech disturbance without motor weakness = 1 point
- Other symptoms (isolated sensory loss, dizziness) = 0 points
D — Duration of Symptoms:
- =60 minutes = 2 points
- 10 to 59 minutes = 1 point
- <10 minutes = 0 points
- D — Diabetes Mellitus: History of diabetes = 1 point
- Clinical Interpretation & Inpatient Triage
Low Risk (Score 0-3): 48-hour stroke risk ~1.0%. May undergo outpatient workup within 24-48 hours if reliable and urgent imaging is available.
Moderate Risk (Score 4-5): 48-hour stroke risk ~4.1%.
High Risk (Score 6-7): 48-hour stroke risk ~8.1% (7-day risk ~12%).
ABIM Board Action Rule for TIA: Any patient with an ABCD2 score >= 4 , crescendo TIAs, focal weakness, symptom duration >10 minutes, or known high-grade ipsilateral carotid stenosis mandates immediate inpatient hospital admission for continuous telemetry, emergent brain MRI with DWI, vascular imaging (CTA or MRA from aortic arch through vertex), transthoracic/transesophageal echocardiography, and immediate initiation of DAPT (Aspirin + Clopidogrel) for 21 days.
3. Spontaneous Intracerebral Hemorrhage (ICH)
Spontaneous non-traumatic intracerebral hemorrhage accounts for 10-15% of all strokes and carries a 30-day mortality approaching 40-50%.
Etiologies and Anatomical Distribution
Hypertensive Arteriopathy (Lipohyalinosis & Charcot-Bouchard Microaneurysms):
Accounts for >65% of primary ICH.
Predilection Sites: Deep subcortical penetrating arterioles supplying the putamen / basal ganglia (50%) , thalamus (15%) , pons (10%) , and cerebellum (10%) .
Clinical Presentation: Sudden focal deficit progressing over minutes to hours, severe headache, vomiting, elevated blood pressure, and depressed level of consciousness.
Cerebral Amyloid Angiopathy (CAA):
Deposition of beta-amyloid in media and adventitia of small-to-medium cortical and leptomeningeal arteries.
Predilection Sites: Lobar hemorrhages (parietal, occipital, frontal) in elderly patients (>65 years) without preceding hypertension.
Neuroimaging: Gradient-echo (GRE) or Susceptibility-Weighted Imaging (SWI) MRI reveals multiple cortical-subcortical microbleeds and cortical superficial siderosis.
Board Rule: Anticoagulation is strictly contraindicated in CAA due to high rates of recurrent fatal lobar ICH.
Emergency Management of Acute ICH
Intensive Blood Pressure Lowering (INTERACT-2 & ATACH-2 Trials):
For patients presenting with SBP between 150 and 220 mmHg, acutely lowering SBP to a target of 130 to 140 mmHg within 1 to 2 hours reduces hematoma expansion and improves functional recovery.
Caution: Avoid dropping SBP <120 mmHg, which increases acute kidney injury and cerebral hypoperfusion.
Use continuous IV titratable infusions: Nicardipine (5-15 mg/h) or Labetalol (10-20 mg IV boluses).
Immediate Anticoagulant Reversal Protocols:
Anticoagulant Agent Immediate Reversal Regimen Mechanism & Administration Rules
Warfarin (VKA) 4-Factor Prothrombin Complex Concentrate (4F-PCC - Kcentra) (25-50 units/kg IV based on baseline INR) PLUS IV Vitamin K (Phytonadione 10 mg) slow IV push 4F-PCC contains non-activated factors II, VII, IX, X and proteins C/S; normalizes INR within 15-30 minutes. Vitamin K sustains hepatic synthesis. Do NOT rely on FFP (too slow, volume overload)
Dabigatran (Direct Thrombin Inhibitor) Idarucizumab (Praxbind) 5 g IV Humanized Fab fragment that binds dabigatran with 350x higher affinity than thrombin; administered as two consecutive 2.5 g IV boluses
Factor Xa Inhibitors (Apixaban, Rivaroxaban, Edoxaban) Andexanet alfa (Andexxa) OR 4-Factor PCC (50 units/kg IV) Andexanet alfa is a recombinant modified human factor Xa decoy protein; 4F-PCC is widely used as a proven alternative if Andexanet is unavailable
Unfractionated Heparin (UFH) Protamine Sulfate 1 mg per 100 units of heparin administered in past 2-3 hours (max 50 mg IV slow push over 10 min)
Neurosurgical Indications for Decompression:
Cerebellar Hemorrhage >=3 cm in Diameter: Mandates emergent neurosurgical posterior fossa decompression and hematoma evacuation if accompanied by neurological deterioration, brainstem compression, or 4th ventricle obstruction causing acute hydrocephalus. Medical therapy alone in this subset carries prohibitive mortality.
Supratentorial Hemorrhage: Routine surgical evacuation of deep basal ganglia ICH is NOT recommended; minimally invasive catheter evacuation or decompressive hemicraniectomy is reserved for life-threatening refractory mass effect.
4. Aneurysmal Subarachnoid Hemorrhage (SAH)
Aneurysmal SAH accounts for ~5% of strokes and results from the rupture of intracranial saccular (berry) aneurysms. The most common anatomical locations are the Anterior Communicating Artery (ACom - 30-35%) , Posterior Communicating Artery (PCom - 25% - often causing ipsilateral CN III palsy with pupil dilation) , and the MCA bifurcation (20%) .
Clinical Presentation & Diagnostic Algorithm
Clinical Hallmark: Sudden, instantaneous onset of excruciating headache peaking within seconds (" thunderclap headache ", "worst headache of my life"), accompanied by photophobia, neck stiffness (meningismus), nausea/vomiting, syncope, and Terson syndrome (preretinal subhyaloid retinal hemorrhages on funduscopy).
Diagnostic Protocol:
Non-Contrast Head CT: Sensitivity is >98-100% within the first 6 hours of headache onset. Blood appears hyperdense in basal cisterns, sylvian fissures, and sulci.
Lumbar Puncture (LP): Mandatory if non-contrast CT is negative or non-diagnostic and clinical suspicion remains high. Classic findings:
Elevated opening pressure (>200 mm H2O).
Persistent, elevated RBC count in tubes 1 through 4 without clearing (distinguishing SAH from a traumatic tap where RBC counts decline significantly from tube 1 to tube 4).
Xanthochromia: Pinkish-yellow discoloration of CSF supernatant resulting from enzymatic breakdown of oxyhemoglobin into bilirubin; detected reliably by spectrophotometry >=6 to 12 hours after hemorrhage and persisting for 2 to 4 weeks.
Vascular Imaging: CTA of the head or Digital Subtraction Angiography (DSA - gold standard) to identify the culprit aneurysm neck morphology and plan endovascular coiling vs surgical clipping.
Major Complications and Inpatient Management
Aneurysmal Rebleeding: Greatest risk is within the first 24 hours (4-10% rate, associated with >50% mortality). Prevented by urgent aneurysm securement via endovascular coiling or surgical clipping within 24 to 48 hours . Pre-operative SBP should be tightly controlled (<140-160 mmHg).
Cerebral Vasospasm & Delayed Cerebral Ischemia (DCI):
Occurs in 30-70% of patients, characteristically developing between days 3 and 14 (peaking at days 7-8) post-hemorrhage due to spasmogenic degradation products (oxyhemoglobin) in the subarachnoid space.
Mandatory Prophylaxis: Oral Nimodipine 60 mg PO every 4 hours for 21 consecutive days (dihydropyridine CCB that crosses the blood-brain barrier; reduces cerebral infarction and improves neurological outcomes; Class I recommendation).
Hemodynamic Management: Maintain strict euvolemia with isotonic crystalloids (0.9% Normal Saline). Prophylactic "Triple-H" hypervolemic hemodilution is no longer recommended. If clinical DCI develops (new focal deficit or drop in Glasgow Coma Scale), initiate induced hypertension with IV vasopressors (e.g., Norepinephrine to target MAP 100-110 mmHg). Perform rescue endovascular intra-arterial vasodilators (Nicardipine/Verapamil) or transluminal balloon angioplasty for refractory vasospasm.
Acute Obstructive / Communicating Hydrocephalus: Managed with emergency placement of an External Ventricular Drain (EVD) .
Hyponatremia in SAH — Cerebral Salt Wasting (CSW) vs SIADH:
Cerebral Salt Wasting (CSW): Driven by excessive central brain natriuretic peptide (BNP) release causing renal sodium wasting and true intravascular volume depletion (low CVP, orthostasis, high urine Na >40 mEq/L). Treatment is volume expansion with isotonic saline (0.9% NS) or hypertonic saline (3% NaCl) plus oral Fludrocortisone .
SIADH: Euvolemic hyponatremia.
CRITICAL BOARD CONTRAINDICATION: Never fluid restrict an SAH patient with hyponatremia. Fluid restriction worsens hypovolemia and drastically precipitates severe cerebral vasospasm, secondary infarction, and death.