What is the primary goal for transfusion?

Primary Goal for Transfusion

The primary goal for transfusion is to treat or prevent a deficit of oxygen-carrying capacity in blood to improve oxygen delivery to body tissues, not simply to achieve an arbitrary hemoglobin number. 1

Fundamental Principle

The overarching objective is to maintain adequate tissue oxygenation and prevent end-organ damage from hypoxia. 1 This requires balancing the benefits of improved oxygen delivery against the risks of transfusion, including:

• Transfusion-related infections (though dramatically reduced with modern screening) 1
• Venous and arterial thromboembolism 1
• Febrile nonhemolytic reactions 1
• Transfusion-related acute lung injury (TRALI) 2
• Immunosuppression 2
• Volume overload 1

Clinical Context-Specific Transfusion Goals

Asymptomatic Patients with Stable Chronic Anemia

For hemodynamically stable patients without acute coronary syndrome, the goal is to maintain hemoglobin 7-9 g/dL. 1 This restrictive strategy has been validated across multiple clinical settings without increasing mortality or morbidity. 3

• Transfusion is rarely indicated when hemoglobin is greater than 10 g/dL 1
• A restrictive threshold of 7-8 g/dL is safe and reduces transfusion exposure by 43% without adverse outcomes 3

Symptomatic Anemia

For symptomatic anemia (including tachycardia, tachypnea, postural hypotension) with hemoglobin < 10 g/dL, the goal is to maintain hemoglobin 8-10 g/dL as needed for prevention of symptoms. 1

Symptoms warranting transfusion include:

• Shortness of breath 4
• Dizziness 4
• Chest pain 5
• Tachycardia unresponsive to fluid resuscitation 5
• Decreased exercise tolerance 4
• Altered mental status 2

Acute Coronary Syndrome or Myocardial Infarction

For anemia in the setting of acute coronary syndromes or acute myocardial infarction, the goal is to maintain hemoglobin 10 g/dL. 1 However, this recommendation requires careful consideration given recent evidence.

• The 2025 MINT patient-level meta-analysis (4,311 patients) found that a liberal strategy (hemoglobin threshold 10 g/dL) did not definitively reduce the composite outcome of MI or death at 30 days compared to restrictive strategy (7-8 g/dL) 6
• However, cardiac death at 30 days occurred in 5.5% with restrictive strategy versus 3.7% with liberal strategy (RR 1.47,95% CI 1.11-1.94) 6
• All-cause mortality at 6 months was higher with restrictive strategy (20.5% vs 19.1%, HR 1.08) 6
• For stable coronary artery disease, transfusion should be considered when hemoglobin is ≤8 g/dL 5

Acute Hemorrhage with Hemodynamic Instability

For acute hemorrhage with evidence of hemodynamic instability or inadequate oxygen delivery, transfuse to correct hemodynamic instability and maintain adequate oxygen delivery. 1

• This represents a clinical emergency where the hemoglobin number is less important than restoring circulating volume and oxygen-carrying capacity 1
• Transfusion is indicated for acute blood loss of more than 30% of blood volume 4

Critical Care Patients

For critically ill patients, the goal is to maintain hemoglobin 7-9 g/dL using a restrictive strategy. 1

• The landmark TRICC trial demonstrated no mortality difference between restrictive (7-9 g/dL) and liberal (10-12 g/dL) strategies in 838 critically ill patients 1
• Restrictive strategies reduce blood product use without increasing morbidity or mortality 1

Brain-Injured Patients

For brain-injured patients, it is probably not recommended to adopt a liberal transfusion strategy targeting hemoglobin > 10 g/dL. 1

• Recent 2025 meta-analysis suggests liberal strategies may reduce sepsis risk and improve neurological recovery in acute brain injury 1
• However, the French Society of Anaesthesia recommends against liberal strategies (>10 g/dL) to decrease morbidity and mortality 1
• For brain tumor surgery, a restrictive threshold of <8 g/dL is safe, though more liberal thresholds (8-10 g/dL) can be used based on clinical judgment 1

Common Pitfalls to Avoid

• Never use hemoglobin level alone as a transfusion trigger - decisions must incorporate clinical context, symptoms, hemodynamic stability, and evidence of inadequate oxygen delivery 2
• Avoid liberal transfusion strategies (>10 g/dL) in most patients - these provide no benefit and may increase complications including thromboembolism and mortality 1, 2
• Do not delay necessary transfusion in febrile patients - fever is not a contraindication to transfusion if clinical criteria are met 7
• Transfuse one unit at a time and reassess - each unit should increase hemoglobin by approximately 1-1.5 g/dL 2
• Consider patient-specific factors - cardiovascular disease, acute coronary syndrome, ongoing bleeding, and symptoms should modify thresholds 5, 2