Study guide
10.1 ICU Glycemic Control & Severe Hypoglycemia
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
10.1 ICU Glycemic Control & Severe Hypoglycemia
Key Takeaways Explain This Topic AI
The NICE-SUGAR trial (2009) found higher 90-day mortality with a glucose target of 81 to 108 mg/dL (27.5%) than with a target of 180 mg/dL or less (24.9%), driven by severe hypoglycemia.
The 2026 Surviving Sepsis Campaign recommends starting insulin at a glucose level of 180 mg/dL or more, aiming for roughly 144 to 180 mg/dL.
Octreotide 50 to 100 micrograms subcutaneously every 6 to 12 hours suppresses the insulin release that causes recurrent hypoglycemia after sulfonylurea overdose.
Severe hypoglycemia with no intravenous access is treated with glucagon 1 mg intramuscularly, which requires hepatic glycogen and fails in alcoholic or fasting liver disease.
Sustained glucose below about 40 mg/dL causes neuroglycopenia and can produce permanent injury; relative hypoglycemia also carries risk in patients whose usual glucose runs high.
Last updated: October 2026
Stress Hyperglycemia and Why Tight Control Failed
Critical illness raises glucose through counterregulatory hormones (cortisol, catecholamines, glucagon, growth hormone), inflammatory cytokines that cause insulin resistance, and iatrogenic loads from dextrose, nutrition, and corticosteroids. Hyperglycemia is associated with infection, impaired neutrophil function, osmotic diuresis, and worse outcomes, which drove early enthusiasm for normalizing glucose.
Trial Design Result
Leuven I (2001) Surgical ICU, target 80–110 mg/dL Lower mortality in a single center with high dextrose feeding
Leuven II (2006) Medical ICU No overall mortality benefit; more hypoglycemia
NICE-SUGAR (2009) 6,104 patients, target 81–108 vs 180 or less mg/dL Higher 90-day mortality with intensive control (27.5% vs 24.9%) , with severe hypoglycemia in 6.8% vs 0.5%
TGC-Fast (2023) Tight control with early parenteral nutrition withheld No benefit from tight control
The lesson is that iatrogenic hypoglycemia and glucose variability cause harm that outweighs the benefit of normal numbers.
Current Targets
Start insulin when glucose reaches 180 mg/dL or more , which the 2026 Surviving Sepsis Campaign recommends for sepsis and septic shock.
Target range : roughly 140 to 180 mg/dL (the SSC describes 144 to 180 mg/dL). Some guidelines accept 110 to 180 mg/dL in selected patients, but targets below about 110 mg/dL are not recommended.
Use a validated IV insulin infusion protocol with frequent monitoring (every 1 to 2 hours until stable, then every 2 to 4 hours).
Avoid variability : hold or reduce insulin when nutrition is interrupted, and remember that stopping a steroid or starting dialysis against a low-glucose bath changes requirements abruptly.
Measurement matters : point-of-care capillary glucose is unreliable in shock, with edema, anemia or polycythemia, and on vasopressors. Confirm extreme or discordant values with an arterial or venous sample on a blood gas analyzer or laboratory assay.
Subcutaneous basal-bolus insulin replaces an infusion when the patient is stable and eating; sliding-scale-only regimens are inadequate.
Severe Hypoglycemia
Definition : Level 1 is glucose below 70 mg/dL, Level 2 below 54 mg/dL, and Level 3 is any severe event with altered mental status or physical impairment. Below about 40 mg/dL , neuroglycopenia produces confusion, seizures, focal deficits, or coma, and prolonged episodes cause permanent injury. Autonomic warning symptoms are blunted by beta-blockers, sedation, and recurrent hypoglycemia.
Causes in the ICU
Category Examples
Iatrogenic Insulin or sulfonylurea dosing errors, interrupted nutrition during an insulin infusion, dialysis with low-glucose dialysate, insulin ordered for hyperkalemia
Drugs Sulfonylureas and meglitinides, quinine, quinolones (rarely), pentamidine, beta-blockers masking symptoms, tramadol
Organ failure Acute liver failure (loss of gluconeogenesis and glycogen), kidney failure (reduced insulin clearance), heart failure, sepsis (late)
Endocrine Adrenal insufficiency, pituitary failure, insulinoma, insulin autoimmune syndrome
Other Alcohol with depleted glycogen, starvation, post-gastric-bypass hypoglycemia, large tumors producing IGF-2, hypoglycemia after glucose-lowering overdoses
Treatment
Give glucose : 25 g of dextrose 50% IV (50 mL), or 10% dextrose in 100 to 250 mL boluses, which is preferred for peripheral veins and in children. Recheck in 15 minutes and repeat as needed.
No IV access : glucagon 1 mg IM or SC . It mobilizes hepatic glycogen, so it fails in alcoholic, fasting, or advanced liver disease, and causes vomiting.
Continuous infusion : start dextrose 10% (occasionally 20% through a central line) when hypoglycemia recurs, and feed the patient.
Sulfonylurea or meglitinide overdose : give dextrose plus octreotide 50 to 100 micrograms subcutaneously every 6 to 12 hours , which suppresses pancreatic insulin release and prevents the rebound hypoglycemia that dextrose alone provokes. Observe for at least 24 hours after the last octreotide dose (longer for chlorpropamide or kidney failure).
Insulin overdose : supportive dextrose, potassium replacement (insulin drives potassium intracellularly), and prolonged observation for depot insulin.
Treat the cause : hydrocortisone for adrenal crisis, thiamine before glucose in possible Wernicke risk, and stop offending drugs.
Warning
Give thiamine 100 to 500 mg IV to malnourished or alcohol-dependent patients when administering glucose. The acute carbohydrate load can precipitate Wernicke encephalopathy in thiamine deficiency.
Pitfalls
Treating the number rather than the patient : a single capillary value in shock should be confirmed.
Dialysis and CRRT : the glucose content of the dialysate or replacement fluid changes insulin needs. Glucose-free solutions cause hypoglycemia, and citrate and lactate loads add calories.
Steroid tapers : insulin needs can halve within hours of stopping high-dose steroids.
Enteral feed interruption : for procedures, reduce or stop short-acting insulin and start dextrose-containing fluid.
Hyperkalemia treatment : after insulin plus dextrose, hypoglycemia occurs commonly within 1 to 3 hours, especially in kidney failure. Check glucose for several hours.
Relative hypoglycemia : a patient whose usual glucose is 250 mg/dL may be symptomatic at 90 mg/dL. Lower chronic hyperglycemia gradually.