Question

Infusions (or intravenous drips) are used to deliver fluids and drugs to patients.

Nurses need to calculate the drip rate, D, in drops per minute for infusions.

They use the formula D =dv/60n where

d is the drop factor measured in drops per milliliter (mL)
v is the volume in mL of the infusion
n is the number of hours the infusion is required to run.

A nurse wants to double the time an infusion runs for.

Describe precisely how D changes if n is doubled but d and v do not change.

Answer 1

D is halved

Explanation:

Given :

• D = -dv/60n

If n is doubled :

• D' = -dv/60(2n)
• D' = -dv/120n
• D' = D/2

When n is doubled, D (the drop factor) is half of its original value.