Intravenous infusion rates
3 marks of the 15 in Part A, which runs for 30 minutes.
Two kinds of question live here. A pump wants millilitres an hour, which is a division. A gravity set wants drops a minute, which needs the drop factor of the set and a conversion from hours to minutes. Knowing which one you have been asked is half the mark.
What this section asks about
- Pump rates: total volume divided by the hours it runs over
- Drip rates: volume times the drop factor, divided by the time in minutes
- Drop factors, which differ between a standard set, a blood set and a micro-drip set
- Recalculating a rate partway through, when an infusion is behind or ahead
- Continuous infusions prescribed in units or micrograms per hour
Where the marks go
3 marks of the 15 in Part A, which runs for 30 minutes.
Every numeracy question sits at the apply and analyse level: you are given a situation and asked to work something out, rather than to recall a fact.
Where candidates lose marks
- Using hours where the formula wants minutes. Multiply by 60 before you divide.
- Assuming a drop factor. The question states it, and 20, 15 and 60 drops per millilitre give three different answers.
- Leaving a drip rate as a decimal. You cannot set half a drop, so round to the nearest whole drop.
Questions people ask
- Do I have to remember the drop factors?
- No. The question tells you the set it wants you to use. What you have to remember is that the factor belongs in the calculation.
- Are infusion questions in Part A or Part B?
- The calculation is in Part A, with the calculator. Part B may ask about the same infusion in clinical terms, such as what to check before it starts.
Practise this section
Practice is filtered by section, so you can work on this one on its own. Every account gets 10 new questions a day without a card.