Final answer:
The question involves calculating and preparing doses of Demerol and Vistaril for injection but cannot be completed without the specific medication orders. The selection of the Vistaril vial depends on these orders, and the preparation for a single injection requires combining the medications in one syringe following safe mixing guidelines and aseptic techniques.
Step-by-step explanation:
The question pertains to calculating drug doses and preparing a combined injection. To provide accurate calculations, the specific orders for both the Demerol and the Vistaril should be known, including dosage strength and frequency. Without this information, it is impossible to calculate the dose. As for which vial of Vistaril to use, it would depend on the doctor's order for the patient's specific needs; however, since we do not have the specific order, we can't determine the exact vial. To prepare a single injection, you would follow aseptic technique to draw the prescribed amount of each medication into the same syringe, assuming they are compatible and safe to mix.
If the drugs can be mixed, first determine the right dose of each, draw up the correct amount of Demerol using a syringe, and then add the correct amount of Vistaril to the same syringe. You must ensure that the total volume is appropriate for intramuscular injection and double-check each step for accuracy.