Final answer:
Sterile water used in a mastectomy is categorized as isotonic to prevent osmotic pressure changes that could damage cells. Isotonic solutions have the same solute concentration as the body tissues, making them safe for medical use to maintain cellular and homeostatic balance.
Step-by-step explanation:
Sterile water used for irrigation during a mastectomy is categorized as D. Isotonic. This categorization is crucial to ensure that the water has the same osmolarity, or concentration of solutes, as that of the body's cells and tissues. This isotonic nature prevents any osmotic imbalance which might cause cells to either swell and burst in a hypotonic solution, or shrink in a hypertonic solution. In medical procedures, isotonic solutions are preferred for intravenous administration and tissue irrigation because they maintain the integrity of cells by preventing osmotic pressure changes.
Use of isotonic solutions align with the need to avoid hemolysis (bursting of red blood cells), which could occur if a hypotonic solution like pure water was used since it has a lower concentration of solutes than that of the body's cells. Hence, in clinical practice, isotonic solutions such as normal saline or lactated Ringer's solution are typically utilized for patient treatment to preserve homeostasis.