Q11

To understand why $1\text{ L}$ is the correct answer, imagine your thigh as a large muscular sleeve. Because the femur is such a massive bone, it needs a lot of blood flowing through and around it. When it breaks, it acts like a burst pipe inside a container.

Simplified Breakdown of Answers

• $250\text{ mL}$ (Incorrect): This is only about the size of a small juice box. A femur fracture is a major medical emergency and bleeds much more than this.

• $500\text{ mL}$ (Incorrect): This is the average amount lost in a smaller bone break, like the humerus (upper arm). Since the femur and thigh are significantly larger, the blood loss is usually double this amount.

• $2\text{ L}$ (Incorrect): This would be nearly $40\%$ of all the blood in an average adult's body. While extremely severe trauma could cause this, it is not the standard clinical estimate for a single femur fracture.

• $1\text{ L}$ (Correct): This is the 'gold standard' estimate for internal bleeding into the thigh from a femur fracture. Medical professionals use this to quickly gauge how much fluid replacement a patient might need.

Mnemonic to Remember: L-I-T-E-R

• L: Large bone

• I: Internal bleeding

• T: Thigh

• E: Estimated

• R: Roughly 1 Liter