Calculation Help

JenRN30, BSN · Dec 24, 2010

If I understand the question right, you would be giving 3 units of PRBC's. At 5 gm/dl, you are 3 gm/dl below 8. 1 unit for each gm x 3 gm below = 3 units.

prettyinblu · Dec 24, 2010

wasnt sure but i thought the same thing :eek:

carolmaccas66, BSN, RN · Dec 24, 2010

This isn't an equation a nurse would be doing. The Dr would have to scan all other blood results and write what you should be giving, unless ur country is different.

merlee · Dec 24, 2010

You were kidding, weren't you? 8 minus 5 equals 3. Please tell me you were kidding, because this is the easiest calculation you will ever do!

GilaRRT · Dec 24, 2010

You were kidding, weren't you? 8 minus 5 equals 3. Please tell me you were kidding, because this is the easiest calculation you will ever do!

Not so fast, let's make this less easy?

1) Let's go ahead and make a proper equation out of this. I will make Hb (x) and PRBC (y). For the sake of setting up this equation I will make y a function of x (y = f of x).

2) So: if x=8, y=0. We know that at a Hb of 8, no blood will be administered. if x=7, y= 1. If Hb drops to 7, we need to give a unit of blood. Since we have a linear relationship, I can easily graph this.

3) Then, using the linear function for slope/intercept (y=mx+b), I can come up with a general formula.

4) Let's take the two coordinates:

(8,0) & (7,1)

5) From this we find m= -1 and b = 8. M being the slope and b being the y intercept.

Slope = rise/run gives us the -1 and the y axis is intercepted at 8.

6) So, now we have a general equation for this problem: ( y = -1x +8).

I could create a differential equation to find the slope, but calculus is not needed for a straight line, so I will leave that out of this discussion.

Sorry OP, I'm just having a little fun...

eoo7l · Dec 24, 2010

Thanks JenRN for helping and explainin! By the way, I did get 3 by subtracting 8 and 5, but I thought there's more to this, and I wasn't sure if I was doing it correctly. Merlee and GilaRN, if I was kidding I wont be asking, thanks for beating people down instead of helping out.

GilaRRT · Dec 24, 2010

Thanks JenRN for helping and explainin! By the way, I did get 3 by subtracting 8 and 5, but I thought there's more to this, and I wasn't sure if I was doing it correctly. Merlee and GilaRN, if I was kidding I wont be asking, thanks for beating people down instead of helping out.

I was not beating you down. In fact, I was making light of Merlee's comment. I also went out of my way to say I was having a little fun. I did so only after your question had been resolved. All fun aside, the equation I worked out does perfectly predict the answer to your problem. In an overly complicated way, but I bet a few people would get a kick out of it.

deboraclark82 · Dec 24, 2010

I found your equation very amusing GilaRN. I'm nerdy like that though lol.

eoo71 I found Merlee to be a little short and demeaning of your question but I am glad that you were given a solution by JenRN. I think that GilaRN was being fun and it was funny to read the reply and follow along to his equation. It's great to look at things from different perspecitves and find many ways to solve different problems. Its keeps the mind out side of the box so to speak :)

Trauma Columnist · Dec 24, 2010

Lets be kind folks - this is the nursing student assistance forum.

We were all students at one time or another - even though for me, we used the abacus and slide rule - lol.

Glad you got the help you needed OP. Take care and good luck in school.

VioletKaliLPN, LPN · Dec 24, 2010

op~

sometimes i think we almost expect things to be more complicated than they truly are. when the answer seems almost too easy, we may second guess ourselves because we think "there has to be a catch...". i have had to learn to stop analyzing questions, this often made them more difficult.

JenRN30, BSN · Dec 24, 2010

Sometimes things are so simple, it's easy to think "what am I missing?" Glad you got your answer eoo71.