IV questions

Question

I'm not sure how to do these two questions.

1. Calculate the direct IV flow rate.

Order: ranitidine hydrochloride 300mg direct IV stat

Supply: ranitidine hydrochloride 300mg/2mL

Package insert instructions: For direct IV injection, dilute 300mg in 0.9% NaCl to a total volume of 20mL. Inject over at least 2 minutes.

Prepare _______ mL randitine.

Dilute with ________ mL 0.9% NaCl for a total of 20mL of solution.

Administer _____ mL/min or _____ mL/15 sec.

The answers are 2, 18, 10, 2.5.

 

2. Calculate the infusion time and completion time for the following IVs.
A) At 1600, D5W 1200mL at 100mL/h was started. The infusion set used is calibrated for a drop factor of 15gtt/mL.

Infusion time: ______h and _____minutes.

Completion time: ________

 The answers are 12 hours, 0400.

Thank you!

Answer 1

I’ve approached this answer through mathematical logic, not medical!

(1) There is 300mg of ranitidine in 2mL. We need 300mg so we need 2mL to be diluted in 20-2=18mL of sodium chloride solution. So this 20mL solution has to be administered over a period of 2 minutes. That is, 20/2=10mL/min or 10/4=2.5mL/15 secs (¼ minute).

(2) At an infusion rate of 100mL/hr it will take 1200/100=12 hours 0 minutes to complete. Start time=1600 (4pm) so finish time =1600+1200=2800, that is, 2800-2400=0400 (4am) the next day. 100mL/hr=100/60=5/3mL/min=15(5/3)=25 drips per minute at 15GTT.