Study guide
13.2 Hypertensive Emergencies & Ruptured Abdominal Aortic Aneurysm
ABIM Critical Care Medicine Study Guide Exam
Track your progress as you read
Finished sections get a check mark.
1 Chapter 1: Exam Orientation: Format, Blueprint & Study Strategy
1.1 ABIM Critical Care Medicine Exam: Format, Blueprint & Study Strategy
2 Chapter 2: Acute Respiratory Failure & ARDS
2.1 ARDS Definition, Pathophysiology & Phenotypes 2.2 Lung-Protective Mechanical Ventilation 2.3 Refractory ARDS: Prone Positioning, Neuromuscular Blockade & VV-ECMO
3 Chapter 3: Obstructive Airways, Pulmonary Vascular & Pleural Emergencies
3.1 Severe Asthma & COPD Exacerbations in the ICU 3.2 Massive & Submassive Pulmonary Embolism 3.3 Pulmonary Hypertension & Right Ventricular Failure in the ICU 3.4 Massive Hemoptysis, Complex Pleural Effusions & Thoracic Drainage
4 Chapter 4: Airway, Parenchymal & Nonthrombotic Pulmonary Emergencies
4.1 Airway Management, Upper-Airway Obstruction & Artificial-Airway Complications 4.2 Diffuse Alveolar Hemorrhage, Interstitial Lung Disease, Pulmonary Vasculitis & Noncardiogenic Edema 4.3 Severe Community-Acquired & Viral Pneumonia 4.4 Nonthrombotic Embolism (Air, Fat, Amniotic Fluid, Tumor, Septic) & Acute Chest Syndrome
5 Chapter 5: Mechanical Ventilation Modes, Dyssynchrony & Liberation
5.1 Mechanical Ventilator Modes & Advanced Breath Delivery 5.2 Patient-Ventilator Dyssynchrony & Waveform Analysis 5.3 Ventilator Liberation, Spontaneous Breathing Trials & Post-Extubation Support
6 Chapter 6: Shock Syndromes & Hemodynamic Principles
6.1 Shock Classification, Cellular Pathophysiology & Biomarkers 6.2 Hemodynamic Monitoring: Arterial Lines, CVP & Pulmonary Artery Catheter 6.3 Dynamic Assessment of Fluid Responsiveness & Resuscitation Targets
7 Chapter 7: Vasoactive Therapies & Mechanical Circulatory Support
7.1 Vasopressors & Inotropes: Pharmacology & Clinical Titration 7.2 Temporary Mechanical Circulatory Support: IABP, Impella & TandemHeart 7.3 Venoarterial ECMO (VA-ECMO) & Differential Hypoxemia 7.4 Post-Cardiac Arrest Care, Targeted Temperature Management & Neuroprognostication
8 Chapter 8: Acute Kidney Injury & Renal Replacement Therapy
8.1 KDIGO AKI Classification, Etiologies & Diagnostic Evaluation 8.2 Continuous Renal Replacement Therapy (CRRT) vs Intermittent Hemodialysis 8.3 Indications & Timing for RRT in Critical Illness: AKIKI & STARRT-AKI
9 Chapter 9: Electrolyte, Acid-Base & Endocrine Emergencies
9.1 Severe Dysnatremias: Hyponatremia, Hypernatremia & Osmotic Demyelination 9.2 Potassium, Calcium, Magnesium & Phosphate Disorders 9.3 Complex & Mixed Acid-Base Disorders: Boston vs Copenhagen vs Stewart 9.4 Endocrine Crises: DKA, HHS, Thyroid Storm, Myxedema Coma & Adrenal Crisis
10 Chapter 10: Glycemic Control, Hyperammonemia, Pituitary & Adrenal Disorders
10.1 ICU Glycemic Control & Severe Hypoglycemia 10.2 Non-Hepatic Hyperammonemia & Metabolic Encephalopathy 10.3 Pituitary Emergencies, Adrenal Excess & Critical Illness-Related Corticosteroid Insufficiency
11 Chapter 11: Acute Coronary Syndromes & Cardiac Arrhythmias
11.1 Acute Coronary Syndromes & Mechanical Complications of Myocardial Infarction 11.2 Critical Tachyarrhythmias: Atrial Fibrillation with RVR, VT & VF 11.3 Critical Bradyarrhythmias, Conduction Blocks & Temporary Cardiac Pacing
12 Chapter 12: Acute Heart Failure, Valvular & Pericardial Emergencies
12.1 Acute Decompensated Heart Failure & Cardiogenic Pulmonary Edema 12.2 Acute Valvular Regurgitation & Prosthetic Valve Emergencies 12.3 Pericardial Tamponade & Acute Aortic Syndromes
13 Chapter 13: Myocardial Disease, Hypertensive & Cardiac Device Emergencies
13.1 Fulminant Myocarditis, Stress & Peripartum Cardiomyopathy, and Hypertrophic Cardiomyopathy 13.2 Hypertensive Emergencies & Ruptured Abdominal Aortic Aneurysm 13.3 Implanted Cardiac Devices, LVAD Emergencies & Electrical Storm
14 Chapter 14: Sepsis & Systemic Infectious Diseases
14.1 Sepsis-3 Definitions & Surviving Sepsis Campaign 2026 Guidelines 14.2 Refractory Septic Shock & Adjunctive Therapies 14.3 Multidrug-Resistant Pathogens & Antimicrobial Stewardship in the ICU
15 Chapter 15: ICU-Acquired & Severe Focal Infections
15.1 Hospital-Acquired & Ventilator-Associated Pneumonia 15.2 Central Line-Associated Bloodstream Infections & Catheter-Associated UTIs 15.3 Intra-Abdominal Sepsis, Necrotizing Soft Tissue Infections & CNS Infections
16 Chapter 16: Focal, Special-Host & Systemic Infections
16.1 CNS Infections Beyond Bacterial Meningitis: Encephalitis, Brain Abscess & Epidural Abscess 16.2 Infections in the Immunocompromised Host, Tropical & Bioterror Infections 16.3 Infective Endocarditis, Device Infections & Other Focal Cardiovascular Infections 16.4 Antimicrobial Pharmacokinetics, Allergy, Toxicity & Infection Prevention 16.5 Gastrointestinal & Hepatobiliary Infections: Fulminant C. difficile, Typhlitis, CMV Colitis & Abscesses
17 Chapter 17: Neurocritical Care & Coma
17.1 Coma, Altered Mental Status & Acute Delirium in the ICU 17.2 Status Epilepticus & Non-Convulsive Status Epilepticus 17.3 Acute Ischemic Stroke & Intracranial Hemorrhage
18 Chapter 18: Cerebrovascular Syndromes, Encephalopathy & Withdrawal States
18.1 Cerebral Venous Sinus Thrombosis, PRES & Reversible Cerebral Vasoconstriction Syndrome 18.2 Alcohol & Sedative Withdrawal, Wernicke Encephalopathy & Drug-Induced Encephalopathy
19 Chapter 19: Intracranial Hypertension & Neuromuscular Weakness
19.1 Intracranial Pressure Monitoring, Cerebral Perfusion & Tiered ICP Management 19.2 Acute Neuromuscular Respiratory Failure, ICU-Acquired Weakness & Brain Death Determination
20 Chapter 20: Traumatic Brain Injury, Spinal Cord Injury & Toxin-Mediated Paralysis
20.1 Traumatic Brain Injury Management & Paroxysmal Sympathetic Hyperactivity 20.2 Acute Spinal Cord Injury, Neurogenic Shock & Autonomic Dysreflexia 20.3 Toxin-Mediated Paralysis & Neuromuscular Crises: Botulism, Tetanus, Tick Paralysis & Myasthenic Crisis
21 Chapter 21: Gastrointestinal, Hepatic & Abdominal Emergencies
21.1 Acute Upper & Lower Gastrointestinal Bleeding in the ICU 21.2 Acute Liver Failure & Severe Acute Pancreatitis 21.3 Abdominal Compartment Syndrome & Acute Mesenteric Ischemia
22 Chapter 22: Luminal GI Emergencies & Complications of Cirrhosis
22.1 Esophageal, Gastric & Bowel Emergencies: Perforation, Obstruction, Ogilvie Syndrome & Colonic Ischemia 22.2 Complications of Cirrhosis: Alcohol-Associated Hepatitis, Hepatorenal Syndrome & Pulmonary Vascular Syndromes
23 Chapter 23: Trauma, Burns & Perioperative Critical Care
23.1 Polytrauma Resuscitation, Damage Control & Massive Transfusion 23.2 Severe Burn Injury, Inhalation Injury & Environmental Emergencies 23.3 Perioperative Critical Care for High-Risk Surgical Patients
24 Chapter 24: Thoracic Trauma, Environmental Injury & Obstetric Critical Care
24.1 Thoracic Trauma: Flail Chest, Pulmonary Contusion, Great Vessel & Tracheobronchial Injury 24.2 Environmental Injury: Drowning, Diving, Altitude, Heat, Cold, Electrical & Radiation 24.3 Obstetric & Genitourinary Emergencies and the Physiology of Pregnancy
25 Chapter 25: Transplantation, Donor Management & Post-Cardiac Surgery Care
25.1 Solid Organ Transplant Recipients & Deceased Donor Management 25.2 Post-Cardiac Surgery Critical Care: Bleeding, Tamponade, Low Output & Vasoplegia
26 Chapter 26: Hematologic Emergencies, Toxicology, Critical Ultrasound & ICU Liberation
26.1 Hematologic Emergencies in the ICU: HIT, DIC, TMA & Anticoagulant Reversal 26.2 Critical Care Toxicology, Toxidromes & Specific Antidotes 26.3 Critical Care Point-of-Care Ultrasound (POCUS) 26.4 ICU Liberation, Analgosedation, Goals of Care & Critical Care Ethics
27 Chapter 27: Transfusion Medicine, Hematologic & Oncologic Disorders
27.1 Transfusion Medicine: Products, Thresholds, Reactions & Apheresis 27.2 Red and White Cell Disorders, Hemoglobinopathies, Factor Deficiencies & Hypercoagulable States 27.3 Oncologic Emergencies, Hematopoietic Cell Transplant Complications & Cellular Therapy Toxicity
28 Chapter 28: Clinical Pharmacology, Adverse Drug Reactions & Specific Poisonings
28.1 Pharmacokinetic Principles, Dose Adjustment & Drug Interactions in Critical Illness 28.2 Adverse Drug Reactions: Anaphylaxis, Severe Cutaneous Reactions & Hyperthermic Syndromes 28.3 Specific Poisonings: Sodium-Channel Blockers, Lithium, Valproate, Theophylline, Iron, Sulfonylureas & Methemoglobinemia
29 Chapter 29: Ethics, Research Methods, Administration & Abdominal Ultrasound
29.1 Advance Care Planning, Nonbeneficial Treatment, Informed Consent & Confidentiality 29.2 Critical Care Research Methods, Statistics, IRB Oversight & Quality Improvement 29.3 Abdominal, Vascular & Procedural Point-of-Care Ultrasound
13.2 Hypertensive Emergencies & Ruptured Abdominal Aortic Aneurysm
Key Takeaways Explain This Topic AI
In most hypertensive emergencies, mean arterial pressure is reduced by no more than about 25% in the first hour, then toward 160/100 mmHg over the next 2 to 6 hours.
Aortic dissection is the exception that requires rapid reduction to a systolic pressure below 120 mmHg and a heart rate below 60 bpm, with beta-blockade before any vasodilator.
Pheochromocytoma crisis is treated with phentolamine or nicardipine first; giving a beta-blocker before alpha-blockade causes unopposed alpha stimulation and a hypertensive catastrophe.
Nitroprusside causes cyanide and thiocyanate accumulation, especially at high doses, prolonged infusion, or with kidney impairment, and raises intracranial pressure.
Ruptured abdominal aortic aneurysm is managed with permissive hypotension (systolic around 70 to 90 mmHg while the patient is conscious) and immediate transfer for repair.
Last updated: October 2026
Emergency Versus Urgency
Hypertensive emergency : severe hypertension (usually above 180/120 mmHg) with acute target-organ injury . The absolute number matters less than the evidence of damage.
Hypertensive urgency : severe hypertension without acute target-organ injury. Treat with oral agents over days and arrange follow-up. Rapid intravenous lowering in this setting causes harm.
Chronic hypertension shifts cerebral autoregulation rightward, so a sudden fall in pressure can cause ischemia even at a "normal" blood pressure. The default is therefore to lower the mean arterial pressure by no more than about 25% in the first hour , then toward 160/100 mmHg over 2 to 6 hours, and to normal over 24 to 48 hours. Several conditions override that default.
Matching the Target to the Target Organ
Condition Target Preferred agents Avoid
Acute aortic dissection Systolic below 120 mmHg and heart rate below 60 bpm within minutes IV esmolol or labetalol first, then nicardipine or nitroprusside Vasodilator before rate control (reflex tachycardia raises shear stress); hydralazine
Acute pulmonary edema (SCAPE) Rapid, large reduction in afterload High-dose nitroglycerin, nitroprusside, plus noninvasive ventilation and loop diuretic Beta-blockers (negative inotropy in decompensated failure)
Acute coronary syndrome Relieve ischemia; systolic below about 140 mmHg Nitroglycerin plus beta-blocker Hydralazine; nitrates with recent phosphodiesterase-5 inhibitor use or inferior infarction with RV involvement
Acute ischemic stroke No treatment unless above 220/120 mmHg (or above 185/110 mmHg before thrombolysis, then below 180/105 mmHg) Labetalol, nicardipine, clevidipine Aggressive lowering, which extends the infarct
Intracerebral hemorrhage Smooth lowering toward systolic 130 to 150 mmHg Nicardipine, clevidipine, labetalol Nitroprusside (raises intracranial pressure); drops below 130 mmHg
Aneurysmal subarachnoid hemorrhage Avoid hypotension and extreme hypertension or variability; no single proven target Short-acting titratable agents Prolonged hypotension
Hypertensive encephalopathy Lower mean pressure by 20% to 25% in the first hour Nicardipine, labetalol, clevidipine Overcorrection
Acute kidney injury or sclerodermal crisis Gradual control; ACE inhibitor is specific in scleroderma renal crisis Nicardipine, clevidipine, fenoldopam; captopril for scleroderma Nitroprusside with kidney failure (thiocyanate)
Severe preeclampsia or eclampsia Systolic below 160 mmHg and diastolic below 110 mmHg; magnesium for seizure prophylaxis IV labetalol, hydralazine, oral nifedipine ACE inhibitors, ARBs, nitroprusside (fetal cyanide risk)
Catecholamine excess (pheochromocytoma, cocaine or amphetamine, clonidine withdrawal, MAO inhibitor crisis) Control the alpha effect first Phentolamine , nicardipine, clevidipine; benzodiazepines for sympathomimetic toxicity Beta-blocker alone (unopposed alpha vasoconstriction)
Perioperative hypertension Pressure close to baseline Esmolol, nicardipine, clevidipine Long-acting agents when swings are expected
Drug Notes
Nicardipine : 5 mg/h, titrated by 2.5 mg/h every 5 to 15 minutes, up to 15 mg/h. Predictable, no reflex tachycardia requirement, but it has a long context-sensitive half-life.
Clevidipine : an ultrashort-acting dihydropyridine in a lipid emulsion; useful when minute-to-minute control is needed. Watch the lipid load and avoid it with soy or egg allergy.
Labetalol : combined alpha-1 and beta blockade, dosed 10 to 20 mg IV then doubled every 10 minutes. Avoid it in decompensated heart failure, bradycardia, and severe asthma.
Esmolol : a very short-acting beta-1 blocker ideal for dissection or when beta-blocker tolerance is uncertain.
Nitroglycerin : predominantly venodilation at low dose, arterial at high dose. First choice for ischemia and acute pulmonary edema; tachyphylaxis develops within 24 to 48 hours.
Nitroprusside : balanced arterial and venous dilation with instant onset. It releases cyanide , which is metabolized to thiocyanate. Risk rises with doses above about 2 micrograms/kg/min, prolonged infusion, and kidney or liver impairment. Suspect toxicity with a rising lactate, a narrowed arteriovenous oxygen difference, and altered mental status. Treat with sodium thiosulfate and hydroxocobalamin; co-infusion of thiosulfate reduces risk. It also raises intracranial pressure and causes coronary steal.
Hydralazine : unpredictable, long-lasting, and causes reflex tachycardia; it is a poor choice in dissection or coronary disease, but is still used in pregnancy.
Fenoldopam : a dopamine-1 agonist that increases renal blood flow; avoid it with glaucoma.
Enalaprilat : useful in high-renin states; avoid it in pregnancy, bilateral renal artery stenosis, and hyperkalemia.
Warning
In clonidine withdrawal , restart clonidine. Giving a beta-blocker first worsens the hypertension through unopposed alpha stimulation, the same trap as in pheochromocytoma.
Hypertensive Encephalopathy and PRES
Hypertensive encephalopathy presents with headache, confusion, seizures, and visual disturbance. MRI typically shows posterior reversible encephalopathy syndrome (PRES) : vasogenic edema in the parieto-occipital white matter. Lower the pressure by 20% to 25% in the first hour, control seizures, and remove precipitants such as calcineurin inhibitors, VEGF inhibitors, and other cytotoxic drugs. Symptoms usually improve within days as the edema resolves; permanent deficits occur with hemorrhage or infarction.
Ruptured Abdominal Aortic Aneurysm
Presentation : the classic triad of abdominal or back pain, hypotension, and a pulsatile mass is incomplete in most patients. Suspect it in any older patient with sudden abdominal or flank pain and hypotension, including presentations mimicking renal colic.
Diagnosis : bedside ultrasound confirms an aneurysm (a diameter above 3 cm) in seconds, although it cannot reliably exclude rupture. CT angiography defines anatomy for endovascular repair in the stable patient; an unstable patient goes directly to the operating room.
Resuscitation :
Permissive hypotension : target a systolic pressure of roughly 70 to 90 mmHg while mentation is preserved. Raising blood pressure dislodges clot and increases bleeding.
Avoid large crystalloid volumes; use a balanced massive transfusion approach.
Keep the patient warm, correct coagulopathy, and give tranexamic acid when trauma protocols apply.
Immediate transfer for repair . Endovascular repair (EVAR) has lower perioperative mortality than open repair in suitable anatomy; both are acceptable, and delay for imaging in an unstable patient is dangerous.
After repair , watch for:
Abdominal compartment syndrome , particularly after EVAR for rupture.
Colonic ischemia , suggested by bloody diarrhea and acidosis (perform flexible sigmoidoscopy).
Spinal cord ischemia, kidney failure, and distal embolization.
Inflammatory and mycotic aneurysms (for example, Salmonella ) present with fever and pain and need antibiotics with repair.