What setting on a burette pump is required to administer 75 mL of fluid containing 75 mg of gentamicin in 40 minutes?

What setting on a burette pump is required to administer 75 mL of fluid containing 75 mg of gentamicin in 40 minutes?

• A. 110 mL/h
• B. 112 mL/h
• C. 113 mL/h
• D. 115 mL/h

Answer: (C)

Infusion rate is determined by how much fluid you deliver over a set period. Here you need to deliver 75 mL in 40 minutes, so convert time to hours: 40 minutes equals 2/3 of an hour. The rate is 75 mL divided by 2/3 h, which is 75 × (3/2) = 112.5 mL/h. Since burette pumps are set in whole mL per hour, round to the nearest whole number: 113 mL/h. The amount of gentamicin (75 mg) in that 75 mL gives a concentration of 1 mg/mL, but the pump setting depends on volume and time, not the total dose. So the appropriate setting is 113 mL/h.

Infusion rate is determined by how much fluid you deliver over a set period. Here you need to deliver 75 mL in 40 minutes, so convert time to hours: 40 minutes equals 2/3 of an hour. The rate is 75 mL divided by 2/3 h, which is 75 × (3/2) = 112.5 mL/h. Since burette pumps are set in whole mL per hour, round to the nearest whole number: 113 mL/h. The amount of gentamicin (75 mg) in that 75 mL gives a concentration of 1 mg/mL, but the pump setting depends on volume and time, not the total dose. So the appropriate setting is 113 mL/h.