π©Έ Pediatric Transfusion Calculator
Weight-based transfusion volumes for children.
For informational purposes only, not medical advice. Consult a healthcare professional.
Pediatric transfusion dosing is weight-based and refreshingly simple: packed red blood cells 10 to 15 mL per kilogram, fresh frozen plasma 10 to 15 mL per kilogram, and platelets roughly 5 to 10 mL per kilogram or one unit per 10 kg. A 10 to 15 mL/kg red cell transfusion typically raises hemoglobin by about 2 to 3 g/dL. This calculator multiplies those standard ranges by weight for quick reference. It is an educational tool; transfusion is a clinical decision involving labs, vital signs, and blood bank protocols.
How to Use This Calculator
Enter the weight in kilograms. The calculator shows standard volume ranges for red cells, plasma, and platelets used in pediatric practice.
Enter the weight. All pediatric blood product dosing scales per kilogram, so weight is the only input needed.
Read the three product ranges: PRBC 10 to 15 mL/kg, FFP 10 to 15 mL/kg, and platelets about 5 to 10 mL/kg.
Remember these are starting estimates. Real transfusion decisions use hemoglobin, platelet count, coagulation studies, and the clinical picture.
How the Math Works
Multiply weight by the low and high end of each range. For a 20 kg child: PRBC 200 to 300 mL, FFP 200 to 300 mL, platelets 100 to 200 mL. The expected hemoglobin rise from PRBC uses the rule that 3 mL/kg raises hemoglobin by about 1 g/dL, so 10 mL/kg gives roughly 3 g/dL in a child without ongoing bleeding. Platelet dosing is often expressed as one apheresis unit per 10 kg or 5 to 10 mL/kg of pooled platelets, expected to raise the count by 50,000 to 100,000. These are teaching values; blood bank products vary in actual volume.
Worked Example
A 20 kg child needing red cells gets 200 to 300 mL of packed red blood cells, expected to raise hemoglobin by roughly 2 to 3 g/dL. The same weight gives 200 to 300 mL for plasma and 100 to 200 mL for platelets. In practice the team orders toward the lower end first, rechecks labs, and gives more only if the numbers and the child say so.
Reading Your Result
The ranges are starting points, not targets to hit automatically. Red cells are given for symptomatic anemia or hemoglobin below threshold with bleeding; plasma for coagulopathy with bleeding or before invasive procedures; platelets for low counts with bleeding or high-risk procedures. Each unit transfused carries risks including reactions, volume overload, and alloimmunization, so the modern ethos is restrictive: transfuse when indicated, not by habit. The child response and repeat labs decide whether more is needed.
| Product | Dose | Expected effect |
|---|---|---|
| Packed red cells | 10-15 mL/kg | Hb up 2-3 g/dL |
| Fresh frozen plasma | 10-15 mL/kg | Factors up ~20-30%% |
| Platelets | 5-10 mL/kg | Count up 50-100k |
Limitations
Product volumes vary by blood bank and collection method, so mL/kg ranges are approximate. Neonates, children with heart failure, and those with ongoing massive bleeding follow specialized protocols, not these ranges. Transfusion thresholds depend on the clinical scenario: a stable child with iron deficiency is managed differently from a trauma patient. This tool teaches the arithmetic; it never indicates a transfusion.
Related Calculators
Related tools: pediatric blood volume calculator reticulocyte count calculator RBC indices interpreter.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
How much blood does a child get in a transfusion?
Typically 10 to 15 mL per kilogram of packed red cells, so a 20 kg child receives 200 to 300 mL. That is far less than an adult unit of about 300 mL of red cells, scaled to the child size. The dose is chosen to raise hemoglobin meaningfully without volume overload.
How much does hemoglobin rise after transfusion?
Roughly 1 g/dL for every 3 mL/kg of packed red cells, so a 10 to 15 mL/kg transfusion raises hemoglobin by about 2 to 3 g/dL in a child who is not actively bleeding. Ongoing bleeding or hemolysis blunts the rise, which is why post-transfusion labs are rechecked.
When do children need plasma (FFP)?
For bleeding with coagulopathy, such as prolonged PT/INR with active bleeding, massive transfusion protocols, or before invasive procedures when clotting factors are low. Plasma is not a volume expander and not for correcting a mildly abnormal INR without bleeding.
What is the platelet dose for a child?
About 5 to 10 mL/kg of pooled platelets, or one apheresis unit per 10 kg of body weight. Expect the platelet count to rise 50,000 to 100,000 per microliter. Febrile or immune-mediated platelet destruction lowers the increment.
What are the risks of transfusion in children?
Allergic and febrile reactions are most common; serious risks include hemolytic reactions from ABO errors, transfusion-associated circulatory overload (TACO), lung injury (TRALI), and alloimmunization affecting future transfusions and pregnancies. Strict identification checks and restrictive thresholds keep risk low.
What is massive transfusion in a child?
Various definitions, often loss of one blood volume in 24 hours or half in 3 hours, or 40 mL/kg. It triggers balanced resuscitation with red cells, plasma, and platelets in near-equal ratios plus attention to calcium, temperature, and acidosis. This is protocol-driven emergency care, not calculator territory.
Can parents refuse transfusion for a child?
This is a sensitive legal and ethical area. In life-threatening emergencies, courts can authorize transfusion for minors over parental objection, and hospitals have protocols for it. Families with objections should discuss bloodless-medicine options with the care team well before any elective procedure.
Why type and crossmatch before transfusion?
To match ABO and Rh and screen for unexpected antibodies that could destroy donor red cells. In true emergencies, uncrossmatched O-negative or O-positive blood is given while the crossmatch runs. The identification checks at the bedside are the last and most critical safety step.
How fast is a pediatric transfusion given?
Red cells typically over 2 to 4 hours per unit equivalent, with vital signs before, during, and after. Faster in bleeding emergencies, slower in children at risk of volume overload. Most reactions appear early, which is why the first 15 minutes get close observation.
What is patient blood management?
The modern approach of minimizing transfusions through anemia treatment before surgery, careful surgical technique, cell salvage, and restrictive thresholds. Children benefit especially since avoiding transfusion avoids its risks entirely. The calculator ranges assume transfusion is indicated; blood management asks whether it can be avoided.