Final answer:
To administer the cimetidine (Tagamet) IV over 20 minutes, the infusion pump should be set to 150 ml/hr. The calculation involves converting the infusion time to hours and applying the rate formula to determine the correct pump setting.
Step-by-step explanation:
The student is asking how to calculate the rate at which an infusion pump should be set to deliver a dose of medication over a specified period. The medication in question is cimetidine (Tagamet), which has been diluted in 50 ml of 0.9% NaCl and needs to be administered over 20 minutes using an IV pump. To find the correct infusion pump rate, we use the formula:
Rate (ml/hr) = (Volume to be infused (ml) ÷ Time (hr)) × 60 minutes/hr
First, we convert the time from minutes to hours: 20 minutes = 20/60 hours = 1/3 hour. Then we apply the formula:
Rate (ml/hr) = (50 ml ÷ 1/3 hour) × 60 minutes/hr
Rate (ml/hr) = (50 × 3) × 60/60
Rate (ml/hr) = 150 ml/hr
Therefore, the infusion pump should be set to 150 ml/hr to deliver the secondary infusion of cimetidine (Tagamet) over 20 minutes.