Estimated Blood Volume for a 2-Year-Old Girl
The estimated blood volume for a 2-year-old girl is 75 cc/kg (or mL/kg). 1, 2
Age-Specific Blood Volume Estimates
A 2-year-old child falls into the pediatric age category of 2-11 years, which has a standardized blood volume estimate of 75 mL/kg according to current guidelines. 1, 2
Developmental Context
Older infants (0.5-2 years) have an estimated blood volume of 75-80 mL/kg, representing the transition period. 1, 2
Children (2-11 years) have a more stable estimate of approximately 75 mL/kg, which your 2-year-old patient has just entered. 1, 2
This represents a physiologic decrease from the neonatal period, when blood volume is highest at 85-100 mL/kg. 2
Clinical Application
Calculating Total Blood Volume
For a typical 2-year-old girl weighing approximately 12 kg:
- Total blood volume = 12 kg × 75 mL/kg = 900 mL 1
Blood Product Dosing Based on This Estimate
- RBC transfusion: 10 mL/kg increases hemoglobin by approximately 20 g/L 2, 3
- Fresh frozen plasma: 10-15 mL/kg 2, 3
- Platelets: 10-20 mL/kg 2, 3
- Cryoprecipitate: 5-10 mL/kg 2, 3
Important Clinical Caveats
The 75 mL/kg estimate is a guideline that does not account for individual variation. 2
Factors affecting actual blood volume include:
- Hydration status - dehydration decreases effective blood volume 2
- Underlying medical conditions - chronic diseases may alter blood volume 2
- Body composition variations - adiposity affects the mL/kg calculation 2
Safe Blood Draw Considerations
Always use weight-based calculations rather than age-based estimates alone when calculating safe blood draw volumes or assessing hemorrhage severity. 2
Only 2% of children up to 3 years old should have a blood volume draw exceeding 1 mL/kg body weight. 4
Each percentage of blood volume lost represents a more significant physiologic insult in smaller children due to their smaller absolute blood volumes. 2