When using the ratio and proportion method for dosage calculations, what is the first step a nurse should take?

Rationale: A. This is incorrect as the first step. Unit conversion may be necessary, but it occurs after the nurse clearly understands what dose is being ordered. Converting too early can lead to errors if the desired dose has not been correctly identified. B. This is incorrect as an initial step. The nurse cannot correctly set up a ratio and proportion equation until the desired dose (what is ordered) is clearly identified. Setting up the equation too soon increases the risk of placing the wrong values into the calculation. C. This is correct. The first and most critical step in the ratio and proportion method is identifying the desired dose, which is the amount of medication the provider has ordered for the client. Understanding exactly what is being prescribed ensures the calculation is based on accurate information and aligns with the six rights of medication administration, particularly the right dose. D. This is incorrect as the first step. While the unit of measurement (mg, mL, units, etc.) is important, it is determined after the desired dose is known and compared with the available dose.