Normal saline, used for priming the dialyzer, is considered what type of solution?

Normal saline is considered an isotonic solution because it has a similar osmotic pressure as bloodstream plasma. This characteristic allows normal saline to maintain the balance of fluids in the body without causing cells to swell or shrink. When normal saline is used for priming the dialyzer in hemodialysis, it ensures that the fluid does not disrupt the osmotic balance of the patient's blood. Isotonic solutions, like normal saline, are essential in medical settings to prevent fluid shifts that could lead to complications such as cellular dehydration or overhydration during treatment.

In contrast, hypotonic solutions have a lower concentration of solutes compared to blood, which could cause cells to swell and potentially burst. Hypertonic solutions have a higher concentration of solutes, which could lead to cellular dehydration as fluid moves out of the cells. Surfactant solutions, not typically related to isotonicity, are used for different purposes, such as reducing surface tension in the lungs, which is not relevant in the context of hemodialysis priming solutions. Thus, normal saline's isotonic nature makes it an appropriate and safe choice for this procedure.