Normal Saline (NS) is preferred over D5W for blood transfusions because:

Normal Saline (NS) is preferred for blood transfusions primarily because it is an isotonic solution. Isotonic solutions have the same osmotic pressure as the blood, which means they can maintain the balance of fluid in the vascular system without causing shifts of fluid into or out of the cells. This helps to preserve the integrity of red blood cells during the transfusion process.

Using an isotonic solution like Normal Saline ensures that the blood components remain stable and functional throughout the transfusion. It helps to prevent hemolysis of the red blood cells, which could occur if a hypotonic solution were used. Hypotonic solutions can lead to cellular swelling and rupture due to an influx of water into the cells, which is not ideal during a blood transfusion. Additionally, isotonic solutions like NS do not interfere with the coagulation factors and other components present in the blood product, ensuring optimal efficacy during the transfusion.