The physician orders ampicillin 2 grams in 50 ml of normal saline to infuse over 30 minutes, and the drop factor on the tubing is 15 gtt/ml. How many gtt/min will the nurse administer?

Choice A reason: To calculate gtt/min: (50 ml / 30 min) × 15 gtt/ml = 25 gtt/min. This accurately reflects the infusion rate, ensuring 2 grams of ampicillin is delivered over 30 minutes. The drop factor (15 gtt/ml) accounts for the tubing’s calibration, providing precise administration to achieve therapeutic antibiotic levels. Choice B reason: A rate of 19 gtt/min underestimates the required infusion speed. Using the formula (50 ml / 30 min) × 15 gtt/ml yields 25 gtt/min. A lower rate prolongs infusion, risking subtherapeutic ampicillin levels, which could reduce efficacy against bacterial infections, making this incorrect. Choice C reason: A rate of 21 gtt/min is incorrect, as (50 ml / 30 min) × 15 gtt/ml equals 25 gtt/min. This miscalculation would slow the infusion, potentially delaying therapeutic ampicillin levels in the bloodstream, reducing its effectiveness in treating infections and risking treatment failure. Choice D reason: A rate of 20 gtt/min is too low, as the correct calculation (50 ml / 30 min) × 15 gtt/ml equals 25 gtt/min. This error could lead to slower drug delivery, reducing ampicillin’s peak concentration, which is critical for bactericidal activity, particularly in severe infections.