Approximately how many milliliters of blood are present per kilogram of body weight in a pediatric patient?

• A. 50
• B. 70
• C. 60
• D. 90

Answer: (B)

In pediatric patients, about 70 milliliters of blood are present per kilogram of body weight. This makes it easy to estimate total blood volume by multiplying the child’s weight in kilograms by 70. For example, a 10 kg child would have roughly 700 mL of circulating blood. This value guides fluid resuscitation and transfusion planning, helping to anticipate how much volume can be lost and how much fluid or blood product to administer. The other numbers are not typical for pediatric blood volume: 50 or 60 mL/kg would undershoot what's expected for a child, while 90 mL/kg is higher and more typical of neonates rather than older children.