Math at Hand: A Mathematics Handbook
A patient receives her nutrition by a stomach tube with the use of a feeding pump. The rate of fluid pumped is usually measured in milliliters per hour (mL/hr). The feeding pump used to infuse the formula in the tube is set to pump at a rate of 300 mL/hr. The patient is fed for only 45 minutes. How many milliliters did this patient receive?
Answer: 225 milliliter
The term milliliter per hour means a certain volume of fluid is to be pumped into a patient for a length of one hour. Therefore, in this problem the patient’s pump is set to feed the patient 300-milliliter of formula for every hour the pump is running. This also means that the rate is set for 300 mL per 60 minutes.
Since the patient received nutrition for only 45 minutes then the student must set up the problem as a ratio and proportion to be able to solve it. The steps are as follows:
[300 mL / 60 min] = [x mL / 45 min] = 225 milliliters
Note that the units for minutes disappear and the student is left with the milliliter units that are required to solve the problem.
©Copyright 2008.Najwa S. Hirn. All rights reserved.
