Intake and output calculation NCLEX review for nurses. This quick review will highlight how to calculate intake and output because these type of questions may be on your NCLEX exam or (definitely) on a nursing lecture exam.
It seems like calculating I and O’s is self-explanatory, right?! Well, it can be tricky, especially calculating intake because many students get confused on what to include, how to convert from ounces to milliliters, and how to interpret the calculation.
Don’t forget to take the intake and output practice calculation quiz after reviewing the material below.
So let’s break it down!
Lecture on I and O’s
What is intake? These are fluids taken IN the body. It can be via various routes like the mouth, a tube, or intravenous (IV).
What do you include for the liquids that are consumed? This includes anything that is liquid at room temperature like:
- Ice chips (NOTE: this melts to half its volume….if you give the patient 8 oz of ice chips RECORD 4 oz)
- Drinks (coffee, soft drinks, tea etc.)
- Gelatin (Jell-O ®)
- Ice cream
- Frozen treats: popsicles, sorbet
- Nutrition supplements like Ensure® or Boost ®
- How about pudding or items similar to it? NO…most NCLEX review guides (example: Kaplan) specify NOT to include pudding etc. in the calculation since it is a semi-liquid (Irwin, Yock & Burckhardt, 2015). However, some sources say to include it (Carter, 2007), but with that being said, ask your professor what they want you to do. However, for this review we will NOT include pudding or products similar to it.
Many times test questions will give you the amount in ounces (oz), but we record intake and output in milliliters (mL). To convert oz to mL, simply multiply the amount of oz by 30.
Example: 67 oz = 2010 mL
- Tube feedings (include free water)
- IV and central line fluids (TPN, lipids, blood products, medication infusion)
- IV and central line flushes
- Irrigants (example: irrigating a catheter….calculate the amount of irrigate delivered and subtract it from the total urine output…which will equal the urine output)
What is output? These are fluids that LEAVE the body. It can be via various routes as well.
- Urine output (most of the output calculation)
- Liquid stool (ostomy or diarrhea)
- Wound draining (drains, tubes…example: chest tubes etc.)
- Suction (gastric, respiratory)
Not included but needs to be considered is: insensible loss
This is from the skin and respiratory system. It can’t be measured. According the Mosby’s Medical Dictionary, insensible loss is estimated to be 600 mL/day (“insensible water loss”, 2018). This varies depending on the patient’s activity level, temperature etc. Therefore, you want to take that in account when assessing if the patient is at risk for fluid volume deficient OR fluid volume overload.
Interpreting Intake and Output
- If the intake is less than output or if the output is MORE than the intake….think DEHYRDATION! The patient is losing too much fluids compared to what they are taking in.
- If the intake is more than output or if the output is LESS than the intake….think that the patient may be retaining fluid and is in FLUID OVERLOAD!
Example: Intake 4250 mL and Output 1210 mL…..patient is at risk for fluid volume overload.
- Carter, P. (2007). Lippincott’s Textbook for Nursing Assistants (2nd ed., p. 403). Lippincott Williams & Wilkins.
- insensible water loss. (2018) Mosby’s Medical Dictionary, 8th edition. (2009). Retrieved February 8 2018 from https://medical-dictionary.thefreedictionary.com/insensible+water+loss
- Irwin, B., Yock, P., & Burckhardt, J. (2015). NCLEX-PN 2015-2016 Strategies, Practice, and Review with Practice Test (p. 127). Simon and Schuster.