28.2 Adverse Drug Reactions: Anaphylaxis, Severe Cutaneous Reactions & Hyperthermic Syndromes

ABIM Critical Care Medicine Study Guide Exam

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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

28.2 Adverse Drug Reactions: Anaphylaxis, Severe Cutaneous Reactions & Hyperthermic Syndromes

Key Takeaways Explain This Topic AI

Intramuscular epinephrine 0.3 to 0.5 mg in the anterolateral thigh is first-line for anaphylaxis, repeated every 5 to 15 minutes, with an infusion for refractory shock.

Patients on beta-blockers with refractory anaphylaxis may respond to glucagon 1 to 5 mg intravenously because it bypasses beta-receptor blockade.

Serotonin syndrome features clonus, hyperreflexia, and mydriasis with rapid onset after a serotonergic drug, whereas neuroleptic malignant syndrome has lead-pipe rigidity and bradyreflexia developing over days.

Malignant hyperthermia follows volatile anesthetics or succinylcholine with masseter spasm, rising end-tidal CO2, and rigidity, and is treated with dantrolene 2.5 mg/kg repeated as needed.

DRESS presents 2 to 8 weeks after drug exposure with fever, rash, eosinophilia, and organ involvement, and often requires systemic corticosteroids with a slow taper.

Last updated: October 2026

Anaphylaxis

Diagnosis is clinical: acute onset with skin or mucosal involvement plus respiratory compromise or hypotension, or two or more organ systems after a likely allergen, or hypotension after a known allergen. Up to 20% of cases have no skin findings , which is why hypotension with bronchospasm after a drug must be treated as anaphylaxis.

Common ICU triggers : beta-lactams and other antibiotics, neuromuscular blockers, iodinated contrast, chlorhexidine, latex, protamine, blood products, and NSAIDs.

Treatment :

Epinephrine 0.3 to 0.5 mg intramuscularly in the anterolateral thigh , repeated every 5 to 15 minutes. Intramuscular dosing gives faster, more reliable absorption than subcutaneous.

Position supine with the legs elevated (sitting a hypotensive patient up has caused "empty ventricle" arrest), give high-flow oxygen, and secure intravenous access.

Fluid resuscitation : 1 to 2 liters of crystalloid rapidly, because massive capillary leak can shift a large share of intravascular volume.

Refractory shock : an epinephrine infusion (0.05 to 0.5 micrograms/kg/min), then norepinephrine or vasopressin. Consider methylene blue for refractory vasoplegia.

Patients on beta-blockers : glucagon 1 to 5 mg IV bypasses the beta-receptor and raises cyclic AMP directly.

Adjuncts (never substitutes for epinephrine): H1 and H2 antihistamines for itch and urticaria, inhaled beta-agonists for bronchospasm, and corticosteroids (which do not treat the acute event and have unproven benefit for biphasic reactions).

Airway : anticipate rapid laryngeal edema; intubate early with a smaller tube, prepared for a surgical airway.

Observe for a biphasic reaction, which recurs in a minority within 1 to 12 hours; severe or epinephrine-refractory cases warrant longer monitoring.

Document the trigger , prescribe an epinephrine autoinjector, and refer for allergy evaluation. A tryptase level drawn within a few hours (with a baseline later) supports the diagnosis.

Hereditary angioedema and ACE inhibitor angioedema do not respond to epinephrine (see the airway section).

Severe Cutaneous Adverse Reactions

Reaction Timing after drug start Features Management

Stevens-Johnson syndrome and toxic epidermal necrolysis 4 days to 4 weeks Painful skin with dusky macules and target lesions, mucosal involvement at two or more sites , positive Nikolsky sign; SJS below 10% body surface area detachment, overlap 10% to 30%, TEN above 30%. Causes include sulfonamides, allopurinol, lamotrigine, carbamazepine, phenytoin, nevirapine, NSAIDs Stop the drug , burn-unit-level care (fluid and electrolyte management, temperature control, wound care, analgesia, ophthalmology and urology involvement), avoid prophylactic antibiotics; cyclosporine, etanercept, or IVIG are used, with steroids debated. SCORTEN estimates mortality

DRESS (drug reaction with eosinophilia and systemic symptoms) 2 to 8 weeks (later than most reactions) Fever, facial edema, morbilliform rash, eosinophilia , lymphadenopathy, hepatitis, kidney injury, myocarditis; HHV-6 reactivation. Causes include allopurinol, anticonvulsants, sulfonamides, vancomycin, minocycline Stop the drug; systemic corticosteroids with a slow taper over weeks , because relapse is common; monitor for late thyroiditis and myocarditis

Acute generalized exanthematous pustulosis Days Sterile pustules on erythema with fever and neutrophilia; usually from beta-lactams Stop the drug; supportive care, topical steroids

Drug-induced vasculitis and serum sickness 1 to 3 weeks Palpable purpura, arthralgia, fever Stop the drug, steroids if severe

Vancomycin infusion reaction Minutes, during infusion Flushing of the face and torso from direct mast cell activation, not IgE-mediated Slow the infusion, antihistamine; the drug can usually be continued

Drug-induced thrombotic thrombocytopenic purpura and immune thrombocytopenia (quinine, ticlopidine, heparin, vancomycin) and drug-induced liver injury complete the systemic picture; severe liver injury with jaundice and coagulopathy requires transplant center discussion.

Hyperthermic Syndromes: Telling Them Apart

Syndrome Trigger and onset Motor and pupillary signs Specific treatment

Malignant hyperthermia Volatile anesthetics or succinylcholine ; minutes to hours (occasionally later) Masseter spasm, generalized rigidity, rising end-tidal CO2 , mixed acidosis, hyperkalemia, rhabdomyolysis Stop the trigger , 100% oxygen with high flows, dantrolene 2.5 mg/kg IV repeated every 5 to 10 minutes to 10 mg/kg or more , active cooling, treat hyperkalemia and arrhythmias ( avoid calcium-channel blockers with dantrolene ), monitor for recrudescence and compartment syndrome

Serotonin syndrome Serotonergic drug addition or overdose: SSRIs, SNRIs, MAO inhibitors, tramadol, fentanyl, linezolid, methylene blue, triptans; within 24 hours Clonus (inducible, spontaneous, ocular), hyperreflexia , tremor, mydriasis , agitation, diarrhea; lower limbs affected more than upper Stop the agents, benzodiazepines, aggressive cooling, cyproheptadine 12 mg then 2 mg every 2 hours; paralysis with a nondepolarizing agent and intubation for severe hyperthermia; avoid antipyretics and physical restraints (isometric contraction raises temperature)

Neuroleptic malignant syndrome Dopamine antagonists (haloperidol, atypical antipsychotics, metoclopramide, promethazine) or withdrawal of dopaminergic therapy ; days to weeks "Lead-pipe" rigidity , bradyreflexia, akinesia, altered consciousness, autonomic instability, very high creatine kinase Stop the antagonist or restart the dopaminergic drug, supportive cooling and fluids, benzodiazepines; bromocriptine or amantadine, and dantrolene for severe rigidity and hyperthermia

Anticholinergic toxicity Antihistamines, tricyclics, scopolamine, jimsonweed Dry flushed skin, mydriasis , urinary retention, absent bowel sounds, delirium with mumbling speech; no clonus or rigidity Supportive care and benzodiazepines; physostigmine for pure antimuscarinic delirium (avoid with a wide QRS or tricyclic overdose)

Sympathomimetic toxicity Cocaine, amphetamines, MDMA, cathinones Diaphoresis (unlike anticholinergic), mydriasis, agitation, hypertension, tachycardia Benzodiazepines, cooling, fluids; avoid beta-blocker monotherapy

Heat stroke Environmental or exertional No specific motor signature; hot skin Rapid cooling (see the environmental section); dantrolene and antipyretics ineffective

Thyroid storm Thyrotoxicosis plus a stressor Hyperreflexia, tremor, atrial fibrillation, goiter, eye signs Beta-blockade, thionamide, iodine after thionamide, steroids

Baclofen or sedative withdrawal Abrupt discontinuation, pump failure Rigidity, fever, autonomic instability Restore the drug urgently; benzodiazepines

The practical discriminators : clonus and hyperreflexia point to serotonin syndrome, lead-pipe rigidity with bradyreflexia to neuroleptic malignant syndrome, a rising end-tidal CO2 during anesthesia to malignant hyperthermia, and dry skin to anticholinergic toxicity (where sympathomimetic toxicity gives wet skin).

Supportive Priorities Common to All

Stop the offending agent and avoid re-exposure (document it prominently).

Cool actively when the core temperature exceeds about 39 to 40 °C: evaporative cooling, ice packs, cold fluids, and intravascular or surface devices. Sedate and paralyze for refractory hyperthermia from muscle activity, because continued contraction generates heat.

Protect the kidneys : fluids for rhabdomyolysis, follow creatine kinase and potassium, and anticipate compartment syndrome.

Treat hyperkalemia and arrhythmias aggressively.

Screen for disseminated intravascular coagulation and hepatic injury , which complicate severe hyperthermia.

Counsel the family in malignant hyperthermia about genetic testing, and report to a registry.