What is "normal saline" in medical settings?

Normal saline is defined as a sterile solution containing sodium chloride (NaCl) dissolved in water, specifically at a concentration of 0.9%. This concentration is isotonic with human blood, meaning it has the same osmotic pressure as bodily fluids, which makes it safe for intravenous use. It is commonly employed in medical settings for a variety of purposes, such as maintaining hydration, delivering medications, and serving as a diluent for other intravenous drugs.

The sterile nature of normal saline ensures that it is free from contaminants, making it suitable for medical procedures. It is also used for flushing IV lines and in wound care. The 0.9% concentration is particularly important as it helps to prevent any cell damage that could occur from hypo- or hypertonic solutions.

Other options provided in the question refer to different types of solutions used in medical settings, but they do not accurately describe normal saline.