Med Math: Drop Factors Question #16


A client came from ER with an order to infuse 400 mL of LR in 4 hours, THEN 600 mL LR to infuse in 8 hours. Infuse the first 4 hours as follows using an infusion pump in ml/hr.


  1. 50 mL/hr
    • Rationale:
  2. 125 mL/hr
    • Rationale:
  3. 100 mL/hr
    • Rationale:
  4. 75 mL/hr
    • Rationale:



Lactated Ringer is to be infused. You would need to know how much volume in ml you need per hour in order to solve. The total volume is set at 400 ml to be infused. The hour is not converted to minutes to solve the problem. The 400 ml to be infused is divided by 4 hours. It should be noted that the problem asks for the first 4 hours of infusion time only not 8 hours. There is a simple formula below for calculating the flow rate. The final answer should have ml/hr within.


—– x 1 (understood to be 1 as in 1 hour)


400 mL/4 hrs = 100 mL/hr

Learning Outcomes

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