Help With Mag/Intake Question

GM2RN · Aug 12, 2011

Depends on if by intake they want fluids or mag. If fluids, there's 1 gm to 25 ml, so in the first half hour the intake is 100 ml, then 100 per hour after that for a total of 850 ml.

If intake is in grams, then intake in the first half hour is 4 gms, then 2 gms per hour after for a total of 19 gms.

You have to learn to focus on what's pertinent and throw out what's not. These types of problems like to confuse you with lots of information that isn't necessary.

klone, MSN, RN · Aug 12, 2011

Depends on if by intake they want fluids or mag. If fluids, there's 1 gm to 25 ml, so in the first half hour the intake is 100 ml, then 100 per hour after that for a total of 850 ml..

No, that's not right. The IV fluid that's 100ml/hour is the maintenance fluid. You have to also add the amount of fluid that they're getting from the Mag.

Rule of thumb is 1 gram of MgSO4 = 25ml.

This is an important type of question to be able to answer because pregnant women who are on Mag are also often on fluid restriction.

This is also a very typical Mg scenario in OB, and something that you would need to figure out regularly if you work in high-risk OB. Of course, now there are smart pumps that figure it all out for you.

klone, MSN, RN · Aug 12, 2011

And I'll help you break it down a bit.

First she gets the Mag bolus for the first 30 minutes. Over the subsequent 7 1/2 hours, she will get a maintenance dose of Mag, as well as maintenance fluid at a rate specified in the question.

LadyinScrubs, ASN, RN · Aug 13, 2011

2g/hr maintenance dose of magnesium from a 40 g in 1000 ml of lr. initial bolus was 4 grams over 30 minutes. iv fluids of 100 ml/hr after bolus. how much intake will client receive in 8 hours?

do you have the answer; it would help to see if we did the correct math. you asked how much intake - that usually means mls.

0-30 minutes: 40 g/1000 ml = 4 grams/ x ml

x = 100 ml

30 minutes to 1.5 hrs: admin iv fluids at 100 ml one hour (subtotal 200 ml)

1.5 hrs to 8 hrs (6.5 hrs): how many mls will you give in 6.5 hrs?

if the infusion is at: 40g/2g an hour. the infusion will take 20 hrs (far longer than your shift)

how many mls will you administer in that 6.5 hrs.

40g/1000ml = 2g an hr / x ml

answer you will administer 50 ml an hour during the last 6.5 hrs of your shift. this means: 50 x 6.5 = 325 ml (subtotal 525 mls during the 8 hr shift)

am i correct or did i make a mistake?

GM2RN · Aug 13, 2011

No, that's not right. The IV fluid that's 100ml/hour is the maintenance fluid. You have to also add the amount of fluid that they're getting from the Mag.
Rule of thumb is 1 gram of MgSO4 = 25ml.
This is an important type of question to be able to answer because pregnant women who are on Mag are also often on fluid restriction.
This is also a very typical Mg scenario in OB, and something that you would need to figure out regularly if you work in high-risk OB. Of course, now there are smart pumps that figure it all out for you.

And I'll help you break it down a bit.
First she gets the Mag bolus for the first 30 minutes. Over the subsequent 7 1/2 hours, she will get a maintenance dose of Mag, as well as maintenance fluid at a rate specified in the question.

But if you read carefully, the question doesn't state that the IV fluids are maintenance fluids. It says that there is a maintenance dose of mag at 2g/hr from the liter bag of LR. It reads to me like the fluids at 100ml/hr are the same fluids, just at a reduced rate after the initial bolus.

This question is poorly written in my opinion. I would be questioning the order if it were real.

ETA: It also doesn't make sense to me that if maintenance fluids were separate that it would make any difference to wait until the initial bolus was given to start them. What difference would 50 ml of presumably NS (as maintenance fluid) gonna make? This is another reason I didn't take the question to mean that there were separate maintenance fluids. BUT, if this is an OB type of question, I'm not an OB nurse, so I'm a little out of my element here.

LadyinScrubs, ASN, RN · Aug 13, 2011

But if you read carefully, the question doesn't state that the IV fluids are maintenance fluids. It says that there is a maintenance dose of mag at 2g/hr from the liter bag of LR. It reads to me like the fluids at 100ml/hr are the same fluids, just at a reduced rate after the initial bolus.
This question is poorly written in my opinion. I would be questioning the order if it were real.
ETA: It also doesn't make sense to me that if maintenance fluids were separate that it would make any difference to wait until the initial bolus was given to start them. What difference would 50 ml of presumably NS (as maintenance fluid) gonna make? This is another reason I didn't take the question to mean that there were separate maintenance fluids. BUT, if this is an OB type of question, I'm not an OB nurse, so I'm a little out of my element here.

I may be mistaken, but this is not a mag question. Isn't the questing asking how much the intake was for the pt for 8 hrs?

GM2RN · Aug 13, 2011

I may be mistaken, but this is not a mag question. Isn't the questing asking how much the intake was for the pt for 8 hrs?

But intake of what? Fluids or mag? Probably fluids, although the question doesn't specify.

But the post you quoted was questioning if there were separate maintenance fluids. Please re-read and you will see what I mean.

LadyinScrubs, ASN, RN · Aug 13, 2011

but intake of what? fluids or mag? probably fluids, although the question doesn't specify.
but the post you quoted was questioning if there were separate maintenance fluids. please re-read and you will see what i mean.[/quote]
i apppreciate the correction; but, was not the topic of the post about iv intake? normally i/o is noted as mls.
thank you, again, for the correction.

GM2RN · Aug 13, 2011

but intake of what? fluids or mag? probably fluids, although the question doesn't specify.
but the post you quoted was questioning if there were separate maintenance fluids. please re-read and you will see what i mean.[/quote]
i apppreciate the correction; but, was not the topic of the post about iv intake? normally i/o is noted as mls.
thank you, again, for the correction.
yes, about intake, and presumably intake of fluids. but there was a difference of opinion of how much fluids based on whether or not the "iv fluids of 100 ml/hr after bolus" is the lr with mag or a separate bag of "maintenance" fluids, which was what i was discussing in the other post that you quoted.

LadyinScrubs, ASN, RN · Aug 13, 2011

yes, about intake, and presumably intake of fluids. but there was a difference of opinion of how much fluids based on whether or not the "iv fluids of 100 ml/hr after bolus" is the lr with mag or a separate bag of "maintenance" fluids, which was what i was discussing in the other post that you quoted.
what was the answer to the med math question that you came up with?

Sarah'sRN'12-2b · Aug 14, 2011

I may be mistaken, but this is not a mag question. Isn't the questing asking how much the intake was for the pt for 8 hrs?

Good Morning LadyinScrubs!

At the end of the post I did state that the tutor instructed that this is an intake question and not a mag question.