# Math Problem - Nursing Student

1. There was a math question on the final exam last semester. I got the wrong answer and none of the teachers were willing to give me the correct answer, or explain to me what I did wrong.

Each semester there is a question like this on the final and I always seem to get stuck on it. It is regarding input and output.

Question : A patient who has a catheter took in 6 oz of Orange Juice and 4 oz of Apple Juice. Irrigation was 2000 ml . At the of the catheter bag reads 2270 ml. What would you record as the patient's input and output?
My answer was 30 input and 270 output. Because 2000 was just irrigation fluid, I subtracted 2270 ml - 2000 ml. Then I subtracted 300 ml from 270 to get input. I don't understand what I did wrong.

Thank you so much!
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Joined: Jan '14; Posts: 2; Likes: 4

3. Why did you 300-270 for input?
4. Quote from Mayberry_02
There was a math question on the final exam last semester. I got the wrong answer and none of the teachers were willing to give me the correct answer, or explain to me what I did wrong.

Each semester there is a question like this on the final and I always seem to get stuck on it. It is regarding input and output.

Question : A patient who has a catheter took in 6 oz of Orange Juice and 4 oz of Apple Juice. Irrigation was 2000 ml . At the of the catheter bag reads 2270 ml. What would you record as the patient's input and output?
My answer was 30 input and 270 output. Because 2000 was just irrigation fluid, I subtracted 2270 ml - 2000 ml. Then I subtracted 300 ml from 270 to get input. I don't understand what I did wrong.

Thank you so much!
If there is 30ml/1oz and the patient had 6oz/180cc of orange juice and 4oz/120ml of apple juice they had a total of 300mls PO intake...right?

If you have a foley irrigation that has infused 2,000mls and you measure 2270mls out of the foley bag...2270mls irrigation/urine - 2000mls/irrigation...you have had 270mls urine output.

Why would you do anything else with you PO intake and output other than to know whether your patient is running positive or negative.

More in than out you are running a positive fluid balance
More out then in you are running a negative fluid balance

You patient for this shift has had a positive fluid balance of 30mls (more in than out) but the total intake and output for this shift is...... a total of 300mls in and 270mls total out...which is your I/O for that shift
5. You need to know how many mLs not oz. There are 30 mLs/oz. PO intake would be 300mLs.

Edit: Rereading the OP, I wasn't able to figure out why you got 30 for input. Did you put 3 mL per oz?
6. OMG I SEE WHAT I DID WRONG NOW. I think I may have read the questions wrong or either I meant to put 300 instead of 30. What in the world was I thinking. OMG!! Thank you all so much!!!! God bless you for taking the time to help me!!!
7. You are welcome.....Read the questions carefully....get rid of the unnecessary crap they put in questions to confuse you. Take a deep breath then do the calculations.

Shame on your teachers for not sitting with you to learn from this.
8. Irrigation counts as input, since it went, well, in. I think your faculty may prefer to see it written like this:

Oral intake = 180cc, 120 cc
Total In: 2300cc
Total Output, Foley = 2270cc
Net: 2300 - 2270 = +30cc

As an alternative, you could do it this way:

Oral intake 180cc, 120 cc = 300cc

Urine: 2270cc - irrigation 2000cc = 270cc

Net: 300 - 270 = +30cc

Either way makes it clearer to you what went where when, so you can see your error.
9. The question is asking for intake and output so you would have two answers.
Intake is 300 ml
Output is 270 ml