For a two-volume exchange on a 145-lb patient with a 40% hematocrit, how much whole blood will be processed?

To determine the volume of whole blood processed during a two-volume exchange, it's essential to understand both the patient's total blood volume and the impact of the hematocrit level.

Firstly, an average estimate of blood volume is typically around 70 mL/kg for an adult. For a patient weighing 145 lbs (approximately 66 kg), the estimated total blood volume can be calculated as follows:

66 kg x 70 mL/kg = 4620 mL, or roughly 4.6 L.

In a two-volume exchange, the aim is to replace the total blood volume twice, which means you would need:

2 x 4.6 L = 9.2 L.

Given this calculation, the amount of whole blood processed would indeed fall into the range of 9-10 L, making it the most accurate choice. This consideration reflects the need to account for the full volume despite the hematocrit level, as the two-volume exchange involves both red blood cells and plasma.

The percentage of hematocrit (in this case, 40%) informs us about the concentration of red blood cells but does not alter the fundamental calculation of total blood volume needed for the exchange. Therefore, the correct choice aligns with the computations related to the