PRBC Transfusion Dosing for a 9-Year-Old Child Weighing 22 kg
For a 9-year-old male weighing 22 kg, transfuse 10-15 mL/kg of packed red blood cells, which equals 220-330 mL (approximately 1 unit), administered over 2-4 hours at an initial rate of 4-5 mL/kg/hour. 1
Volume Calculation
- Standard pediatric dosing is 10-15 mL/kg of PRBCs 1, 2
- For this 22 kg patient: 220-330 mL total volume
- This approximates one standard adult unit (typically 300 mL) 3, 4
- Each unit should raise hemoglobin by approximately 1 g/dL or hematocrit by 3% in stable patients without ongoing blood loss 3, 5
Infusion Rate and Duration
- Initial infusion rate: 4-5 mL/kg/hour 1
- For 22 kg patient: 88-110 mL/hour
- Total transfusion time: 2-4 hours per unit 1
- Maximum time limit: Must complete within 4 hours of removal from temperature-controlled storage to prevent bacterial proliferation and hemolysis 1, 2
- Slower rates (lower end of range) should be used for patients with cardiovascular comorbidities to reduce risk of transfusion-associated circulatory overload 1
Administration Protocol
Pre-transfusion requirements:
- Crossmatch PRBCs to confirm ABO compatibility and screen for antibodies 4
- Document baseline vital signs (temperature, heart rate, blood pressure, respiratory rate) 4
Ordering approach:
- Order exactly 1 unit at a time, never multiple units simultaneously 4
- Reassess clinically after each unit before ordering additional units 4
Monitoring schedule:
- Close vital sign monitoring during first 30 minutes to detect acute transfusion reactions 1
- Repeat vital signs at 15 minutes after starting and again at completion 4
- Clinical assessment before, during, and after each unit 1
Premedication Considerations
- Premedication with acetaminophen or antihistamines is seldom required for patients not planned for long-term transfusion 4
- If repeated transfusions are anticipated, consider leukocyte-reduced blood and premedication to minimize adverse reactions 4
Clinical Context for Transfusion Decision
While the question asks about volume, the decision to transfuse should be guided by:
- Restrictive transfusion threshold: Hemoglobin <7 g/dL for hemodynamically stable children 6
- This threshold is supported by strong evidence showing no adverse effects on mortality or morbidity compared to liberal strategies (hemoglobin 9-10 g/dL) 6, 7
- Transfusion at lower hemoglobin concentrations (closer to 7 g/dL) produces a greater hemoglobin rise per unit transfused 8
Important Caveats
Special populations requiring different thresholds:
- Children with congenital heart disease may require higher thresholds: 7 g/dL (biventricular repair), 9 g/dL (single-ventricle palliation), or 7-9 g/dL (uncorrected disease) 6
- Critically ill children with severe hypoxemia, cyanotic cardiac conditions, or hemoglobinopathies may require individualized thresholds 6
Common pitfalls to avoid:
- Do not assume transfusion corrects underlying iron deficiency—obtain pre-transfusion iron indices and provide supplemental iron therapy if needed 4, 5
- Do not routinely volume-reduce PRBCs, as 15-55% of platelets are lost during additional centrifugation 4
- Be aware of transfusion risks including venous thromboembolism (OR 1.60), arterial thromboembolism (OR 1.53), and increased mortality (OR 1.34) in certain populations 3, 4