Symptom severity may still be significant with lower reserve
Bleeding priorities
Ectopic pregnancy exclusion
Placental abruption concern if pain and bleeding
Transfusion thresholds
Symptom driven transfusion
Maternal hypoperfusion risk
Fetal oxygen delivery considerations
Iron therapy preference
Oral iron first line if stable
IV iron if intolerance or late pregnancy severe deficiency
Geriatric
Older adult considerations
Lower physiologic reserve
Earlier ischemic symptoms at higher hemoglobin values
Occult GI malignancy risk
Iron deficiency anemia triggers endoscopic evaluation pathway
Transfusion risk
TACO higher risk
Slower rate
Diuretic strategy when appropriate
Polypharmacy bleeding risk
Anticoagulant plus antiplatelet combinations
Pediatrics
Pediatric considerations
Normal hemoglobin varies by age
Age specific reference ranges
Etiology differences
Nutritional iron deficiency common
Hemoglobinopathies
Bone marrow failure syndromes
Transfusion dosing
PRBC 10 to 15 mL/kg
Recheck hemoglobin and symptoms after transfusion
Child protection consideration
Unexplained severe anemia with bruising or neglect concern triggers safeguarding pathway
Background
Epidemiology
Population patterns
Common causes in ED
Iron deficiency from chronic blood loss
Acute blood loss
Anemia of chronic disease
Iron deficiency clues
Heavy menstrual bleeding as common contributor in reproductive age
Occult GI bleeding as key contributor in older adults
High risk groups
CKD patients
Cancer patients
Elderly
Pathophysiology
Oxygen delivery physiology
Oxygen delivery equals cardiac output times arterial oxygen content
Hemoglobin is primary determinant of oxygen content
Compensation in anemia
Increased heart rate
Increased stroke volume
Decreased blood viscosity
Increased 2,3-BPG with right shift of oxyhemoglobin curve
Decompensation triggers
Limited cardiac reserve
Coronary stenosis
Ongoing blood loss
Therapeutic Considerations
Transfusion benefits and harms
Benefits
Rapid increase in oxygen carrying capacity
Symptom relief in tissue hypoxia
Harms
TACO risk
TRALI risk
Hemolytic transfusion reaction risk
Alloimmunization risk
Infection transmission risk is low but nonzero
Restrictive vs liberal transfusion
Restrictive strategy preferred in stable patients
Individualization in ischemic heart disease and ongoing bleeding
Evidence level labeling for bedside decisions
ACEP Level C recommendation
Symptom guided transfusion in ED when hemoglobin threshold alone insufficient
Class I recommendation
Immediate transfusion for life-threatening anemia with shock physiology
Class IIa recommendation
Transfusion consideration for symptomatic ischemia likely driven by anemia
Patient Discharge Instructions
Copy discharge instructions
Discharge instructions for anemia
Diagnosis
Anemia with suspected cause documented in ED
Medications
Iron or vitamin supplementation as prescribed
Avoid NSAIDs if bleeding concern unless clinician approved
Diet
Iron rich foods
B12 and folate sources when relevant
Follow up
Follow up appointment timeframe listed
Repeat blood test timeframe listed
Return to ED immediately for
Chest pain
Shortness of breath at rest
Fainting or near fainting
Rapidly worsening weakness
New confusion
Black tarry stools
Vomiting blood
Heavy vaginal bleeding
Severe abdominal pain
Fever after recent transfusion
Safety note
If symptoms worsen before follow up, return to ED
References
Clinical guidelines and society statements
Transfusion guidelines
AABB RBC transfusion guideline
Restrictive transfusion thresholds in stable hospitalized adults
One unit transfusion and reassessment strategy
NICE blood transfusion guideline
Restrictive thresholds
Patient blood management principles
British Society for Haematology guidance
Iron deficiency anemia management
Autoimmune hemolytic anemia management
Evidence based sources and tools
Decision support and evidence summaries
Glasgow Blatchford score derivation and validation literature
Massive transfusion protocol evidence base in trauma resuscitation
Transfusion reaction definitions and hemovigilance resources
CKD anemia guidance for ESA and iron optimization
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.