Which method is an example of Class II isotonicity adjustment?

• A. White Vincent Method
• B. NaCl Equivalent Method
• C. Liso Method
• D. Osmolarity Adjustment

Answer: (B)

Isotonicity adjustment can be done in different ways, but Class II focuses on a calculation that translates every solute’s osmotic effect into an equivalent amount of NaCl. The NaCl Equivalents Method does just that: it uses the solute’s NaCl equivalent (an E value) to convert how much NaCl would produce the same osmotic pressure as the solute. By figuring out how much NaCl is needed to reach isotonicity, you can adjust the solution accurately without direct osmolar measurements. This calculation-based approach is what characterizes Class II isotonicity adjustments.

Other options are methods or concepts that don’t rely on the NaCl-equivalent calculation. For example, the White-Vincent approach is an empirical way to assess tonicity, not a direct NaCl-equivalent adjustment. Osmolarity adjustment is the broader goal—achieving the same osmotic pressure as bodily fluids—which can be done by various agents, not solely through the NaCl-equivalent method. The Liso method isn’t a standard Class II calculation method.