27.1 Transfusion Medicine: Products, Thresholds, Reactions & Apheresis

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

27.1 Transfusion Medicine: Products, Thresholds, Reactions & Apheresis

Key Takeaways Explain This Topic AI

The TRICC and TRISS trials support a hemoglobin transfusion threshold near 7 g/dL in critically ill and septic shock patients, with TRICS III supporting 7.5 g/dL in cardiac surgery.

Transfusion-related acute lung injury presents within 6 hours with hypoxemia and bilateral infiltrates and normal filling pressures, whereas TACO features hypertension, elevated filling pressures, and a diuretic response.

Acute hemolytic transfusion reaction from ABO incompatibility causes fever, flank pain, hemoglobinuria, and disseminated intravascular coagulation; the first step is stopping the transfusion and supporting renal perfusion.

Anaphylactic reaction to plasma-containing products in a patient with IgA deficiency requires washed cellular products and IgA-deficient plasma.

Therapeutic plasma exchange is first-line therapy for TTP, Guillain-Barre syndrome, myasthenic crisis, anti-GBM disease, and symptomatic hyperviscosity.

Last updated: October 2026

Products and When to Use Them

Product Content and effect Typical ICU use

Packed red cells One unit raises hemoglobin by about 1 g/dL Anemia with impaired oxygen delivery; see thresholds below

Platelets One apheresis unit raises the count by about 30,000 to 50,000/µL Bleeding with a count below 50,000/µL (below 100,000/µL for CNS or ophthalmic bleeding), prophylaxis below 10,000/µL, or before procedures

Plasma All coagulation factors, about 10 to 15 mL/kg to raise factor levels meaningfully Bleeding with multifactor deficiency; not for isolated INR correction before low-risk procedures

Cryoprecipitate Fibrinogen, factor VIII, von Willebrand factor, factor XIII, fibronectin Fibrinogen below about 150 mg/dL with bleeding; disseminated intravascular coagulation; postpartum hemorrhage

Prothrombin complex concentrate (4-factor) Factors II, VII, IX, X with low volume Warfarin reversal with major bleeding; factor Xa inhibitor-associated bleeding

Fibrinogen concentrate Standardized fibrinogen dose Hypofibrinogenemia, especially in cardiac surgery and obstetrics

Albumin Colloid; 25% for paracentesis and hepatorenal syndrome Large-volume paracentesis, spontaneous bacterial peritonitis, hepatorenal syndrome; not routine resuscitation, and avoided in traumatic brain injury

Modified products Irradiation prevents transfusion-associated graft-versus-host disease (for hematopoietic cell transplant recipients, those receiving purine analogues, and directed donations from relatives); leukoreduction reduces febrile reactions, CMV transmission, and alloimmunization; washing removes plasma proteins for IgA deficiency or repeated severe allergic reactions Match the modification to the mechanism

Transfusion Thresholds

• Population Threshold
• General critically ill (TRICC) 7 g/dL
• Septic shock (TRISS) 7 g/dL
• Upper gastrointestinal bleeding 7 g/dL (restrictive strategy improved survival in cirrhosis)
• Cardiac surgery (TRICS III) 7.5 g/dL

Myocardial infarction (MINT) A liberal strategy near 10 g/dL may be preferred; evidence is less definitive, and 8 to 10 g/dL is commonly used

• Hip fracture and cardiovascular disease (FOCUS) 8 g/dL or symptoms
• Active major hemorrhage Balanced ratios rather than a hemoglobin threshold

Transfuse one unit at a time and reassess, except in active hemorrhage.

Acute Reactions: Recognizing Them by Pattern

Reaction Timing and features Management

Acute hemolytic (ABO incompatibility) Minutes: fever, chills, flank or back pain, hemoglobinuria , hypotension, disseminated intravascular coagulation; in an anesthetized patient, bleeding and hypotension may be the only clues Stop the transfusion , maintain intravascular volume and urine output, send the unit and samples for investigation, support with products as needed

Febrile nonhemolytic A rise of 1 °C or more with chills, from cytokines or recipient antibodies to donor leukocytes Stop, exclude hemolysis and sepsis, give an antipyretic; leukoreduced products thereafter

Allergic (urticarial) Hives without systemic features Pause, give an antihistamine, resume cautiously

Anaphylaxis Minutes: bronchospasm, angioedema, shock; classically in IgA deficiency with anti-IgA antibodies, or haptoglobin deficiency Stop, give epinephrine and supportive care; future transfusions use washed cellular products and IgA-deficient plasma

TRALI Within 6 hours : hypoxemia with bilateral infiltrates, no evidence of volume overload (normal filling pressures), often fever and transient leukopenia; from donor antibodies or bioactive lipids priming neutrophils Supportive: lung-protective ventilation; diuretics do not help ; report to the blood bank so donors can be evaluated

TACO Within 6 to 12 hours: dyspnea, hypertension , elevated filling pressures and BNP, responds to diuresis Slow or stop the transfusion, upright positioning, diuretics, oxygen; prevent by transfusing slowly in patients at risk

Bacterial contamination High fever, rigors, shock within minutes to hours; platelets are the highest-risk product because of room-temperature storage Stop, culture the patient and the unit, broad-spectrum antibiotics

Hypotensive reaction Isolated hypotension, associated with ACE inhibitors and bradykinin generation Stop; usually self-limited

Citrate toxicity Massive or rapid transfusion, or apheresis: ionized hypocalcemia with paresthesias, QT prolongation, and reduced contractility Calcium chloride or gluconate, with ionized calcium monitoring

Delayed reactions : delayed hemolysis (3 to 14 days, with a falling hemoglobin and a new antibody), alloimmunization, post-transfusion purpura, iron overload, and transfusion-associated graft-versus-host disease (rash, diarrhea, pancytopenia, and liver dysfunction 1 to 6 weeks later in susceptible patients, which is nearly always fatal and is prevented by irradiation).

Massive transfusion complications : hypothermia, dilutional coagulopathy, hyperkalemia from stored cells, hypocalcemia from citrate, metabolic alkalosis as citrate is metabolized, and acidosis from hypoperfusion.

Special Transfusion Situations

Sickle cell disease : use phenotypically matched units to limit alloimmunization; exchange transfusion for acute chest syndrome, stroke, and preoperative preparation in selected cases. Suspect hyperhemolysis syndrome if the hemoglobin falls after transfusion with reticulocytopenia.

Warm autoimmune hemolytic anemia : transfusion is not contraindicated in severe anemia, although crossmatching is difficult; give the "least incompatible" unit while treating with steroids.

Cold agglutinin disease : warm the patient and use a blood warmer.

Jehovah's Witness patients : establish which products and techniques are acceptable in advance; use erythropoietin, intravenous iron, cell salvage, tranexamic acid, and meticulous blood conservation.

Platelet refractoriness : suspect alloimmunization (HLA antibodies) when counts fail to rise; use HLA-matched platelets. Avoid platelet transfusion in TTP and HIT unless there is life-threatening bleeding.

Apheresis and Plasma Exchange

Therapeutic plasma exchange removes plasma (with its pathogenic antibodies, immune complexes, or paraproteins) and replaces it with albumin or plasma. Replacement with plasma is needed in TTP (to supply ADAMTS13) and when there is coagulopathy.

• First-line (Category I) indications relevant to the ICU Notes
• TTP Daily exchange with plasma replacement, plus steroids and caplacizumab
• Guillain-Barré syndrome Equivalent to IVIG; do not combine
• Myasthenic crisis May act faster than IVIG
• Anti-GBM disease (Goodpasture) With steroids and cyclophosphamide

ANCA vasculitis with severe disease PEXIVAS showed no benefit for death or end-stage kidney disease; use is individualized

• Hyperviscosity syndrome (Waldenström macroglobulinemia, myeloma) Rapid symptom relief
• Severe hypertriglyceridemia with pancreatitis When insulin and supportive therapy fail
• Acute liver failure High-volume plasma exchange improved transplant-free survival in a randomized trial
• Transplant desensitization and antibody-mediated rejection With IVIG and rituximab

Leukapheresis is used for symptomatic hyperleukocytosis (leukostasis), and red cell exchange for acute chest syndrome, stroke in sickle cell disease, and severe babesiosis or malaria in selected cases.

Complications of apheresis : citrate-induced hypocalcemia, hypotension, catheter complications, coagulation factor depletion (with albumin replacement), and removal of therapeutic drugs and antibodies, so timing with medication dosing matters.