Question About Fluid Resuscitation with Burns

chare · Nov 6, 2017

Based on your calculations that the parient should have received 3100 mL in the first 8 hours but were started an hour late, they should have been starred at 442.9 mL/hour, which you calculated. If now, 6 hours post injury you need to adjust the rate calculate the total volume received and subtract that from 3100 and run the remainder over the remaining two hours.

Ues, the calculate fluid volume is infused in the first eight hours because the fluid loss occurs beginning at the time of injury.

KrCmommy522, BSN, RN · Nov 6, 2017

Thanks for your response!

What do you mean if now, 6 hrs post injury, you need to adjust the rate calculate the total volume received and subtract that from 3100 and run the remainder over the remaining 2 hrs?

Do you mean that you would take 3100/7 = 442.9 then take 442.9 x 6 hrs = 2,657.4 mL, so then you take 3100 - 2657.4 = 442.6 mL, so 442.6 mL needs to run over the remaining 2 hrs = 442.6/2 = 221.3 mL/hr?

chare · Nov 6, 2017

[...]
Do you mean that you would take 3100/7 = 442.9 then take 442.9 x 6 hrs = 2,657.4 mL, so then you take 3100 - 2657.4 = 442.6 mL, so 442.6 mL needs to run over the remaining 2 hrs = 442.6/2 = 221.3 mL/hr?

I might have misread your post, but it seemed you were talking about adjusting the rate mid infusion.

When you use this formula, half of the calculated volume infuses in the first 8 hours, from the time of injury. In your scenario, if the fluids were initiated at the time of injury, the infusion rate would be 387.5 mL/hour. As they were started 1 hour post injury the 3100 mL needs to infuse at 442.9 mL/hour. If they were started 2 hours poadd t injury, the 3100 would need to infuse at 516.7 mL/hour. If the infusion is started at the appropriate rate, it shouldn't need to be adjusted.

If, on the other hand, the infusion is started either too fast or too slow, when you receive the patient you will need to adjust the rate. For example, I'll use your patient, that should receive 3100 mL in the first 8 hours. If the infusion were started 1 hour post injury at 300 mL/hour as opposed to the calculated 442.9 mL/hour and arrives at your facility 3 hours post injury. He has received a total of 600 mL fluid. Based upon your initial calculations, and if the fluids were started at the time of injury, he should have received 1162.5; resulting in a degicit of 562.5 mL. In this situation you would need to adjust the rate to ensure that the patient receives the total calculated replacement fluid. To do this subtract the volume delivered from the calculated volume, and deliver the remainder over the remaining time, or: (3100-600)Ã·5, or 500 mL/hour. Of the infusion were stsrted too fast, you would also use this method to calculate the new, decreased rate.

I apologize for any confusion or lack of clarity in my previous post.

KrCmommy522, BSN, RN · Nov 6, 2017

No problem! I just appreciate your response!!

Ok, so I get what you are saying. My only question is that in your example of the pt receiving the wrong rate at 300 mL/hr and arriving to the hospital 3 hrs post injury. Wouldn't he have received 900 mL of fluid (300 mL/hr x 3 hrs) as opposed to the original calculation of 442.9 mL hr, he should have received 1328.7 mL; resulting in a deficit of 428.7 mL. The remaining time is 5 (since he arrived 3 hrs post injury), so (3100 - 428.7)/5 = 2671.3/5 = 534.3 mL/hr?

Sorry I keep asking questions! But thank you so much for helping me understand this more!!

chare · Nov 6, 2017

No, I used your original scenario where the fluids were started 1 hour post injury.

I think you get this. Always remember these two points when calculating fluid replacement for burn patients. The first is that the patient receives half of the calculated volume in the first 8 hours, based upon the time of injury. Second, when you receive the patient you need to determine how much fluid he has received and calculate the remaing volume so that you verify that at the current infusion rate he will receive the correct volume of fluid replacement.

KrCmommy522, BSN, RN · Nov 7, 2017

I understood you were using my example, but when you went further to say that if the infusion had been started either too fast or too slow:

If, on the other hand, the infusion is started either too fast or too slow, when you receive the patient you will need to adjust the rate. For example, I'll use your patient, that should receive 3100 mL in the first 8 hours. If the infusion were started 1 hour post injury at 300 mL/hour as opposed to the calculated 442.9 mL/hour and arrives at your facility 3 hours post injury. He has received a total of 600 mL fluid. Based upon your initial calculations, and if the fluids were started at the time of injury, he should have received 1162.5; resulting in a degicit of 562.5 mL. In this situation you would need to adjust the rate to ensure that the patient receives the total calculated replacement fluid. To do this subtract the volume delivered from the calculated volume, and deliver the remainder over the remaining time, or: (3100-600)Ã·5, or 500 mL/hour. Of the infusion were stsrted too fast, you would also use this method to calculate the new, decreased rate.

I think I misunderstood a part of it. So, when you say that if the infusion was started at 300 mL/hr 1 hr post injury, and the pt arrives to the hospital 3 hrs post injury, then the pt would have been receiving the fluids for 2 hrs (not 3, since fluids were started 1 hr post injury). So, the pt would have received a total of 600 mL of fluids (300 mL/hr x 2 hrs).

Now, if the fluids had been running at the correct rate of 442.9 mL/hr, the pt should have received 1328.7 mL (the pt arrived 3 hrs post injury, so at a rate of 442.9 mL/hr x 3 hrs = 1328.7 mL). However, fluids were running at 300 mL/hr and were started an hr late, so pt only received 600 mL, which results in a deficit of 728.7 mL. The remaining time is 5 hrs (because arrived 5 hrs post injury), so (3100 - 728.7)/5 = 2371.3/5 = 474.26 = 474.3 mL/hr.

So, I think I understood what you were saying - other than the part where you said the fluids were started an hr after the injury (like in my problem) but were running at 300 mL/hr and the pt arrived to the hospital 3 hrs post-injury - I was using 3 hrs for how long the wrong rate of 300 mL/hr was running, when I needed to use the time the fluids were started, which was an hr late, so 2 hrs needed to be used.

I'm just confused as to where you get the pt should have received 1162.5 mL. If the fluids were running at 442.9 mL/hr for 3 hrs, the pt should have received 1328.7? Correct?

Again, sorry if I'm being a pain! I just want to fully understand this!

student_B, ADN, RN · Nov 7, 2017

TBSA% Burned is 31%. The pt weighs 50 kg. The burn injuries occurred at 0300. Fluid resuscitation was started at 0400, and it is now 0900.
Calculate her fluid replacement for the first 24 hours, specify how much will be given, what time intervals will be used, and what the infusion pump should be set for (in mL/hr).
Pt burned at 0300
TBSA Burned = 31% Pt Weight = 50 kg
Started fluid resuscitation at 0400 (1 hr AFTER time of injury)
Time Now = 0900 (fluids going for 5 hrs)
4 mL x 50 kg x 31% = 6200 mL for 24 hrs
6200 mL/2 = 3100 mL
Pt gets 3100 mL in first 8 hrs
Pt gets 3100 mL in next 16 hrs
You have to adjust the formula to reflect initiation of fluids at the time of injury

The way I read this problem is that

-3100mL should be given within the first 8hrs (0300-1100)

-It is now 0900 and the rate needs to be adjusted

-0400-0900 @ 3100mL/8hr ordered rate = 387.5mL/hr x 5hrs infusion = 1937.5mL infused so far.

the remainder of the 3100mL must complete in next 2hrs (0900-1100),

so 3100-1937.5mL leaves 1162.5mL to infuse over 2hrs.

1162.5mL/2hrs = 581.25mL/hr. Therefore, now (0900) you set the pump to infuse at 581mL/hr (or 581.2 or 581.3 depending on rounding policy) to infuse the remainder of the 3100mL within 8hrs post-injury(1100).

Then, at 1100 set the pump at 193.75mL/hr (3100mL/16hrs) to finish the order.

Very similar to your OP, except in the OP the rate is adjusted at 0400 (1hr post injury) whereas I read the question as "its been infusing at the 8hr rate, but was started 1hr late and has been going for 5hrs, how do you adjust the rate to ensure the 3100mL completes 8hr post-injury?"

P.S. I haven't gotten this far in NS yet, is the 4mL x weight x %bsa burned a standard formula?

KrCmommy522, BSN, RN · Nov 8, 2017

All right....I am totally confused now!!

The way I read this problem is that
-3100mL should be given within the first 8hrs (0300-1100)
-It is now 0900 and the rate needs to be adjusted
-0400-0900 @ 3100mL/8hr ordered rate = 387.5mL/hr x 5hrs infusion = 1937.5mL infused so far.
the remainder of the 3100mL must complete in next 2hrs (0900-1100),
so 3100-1937.5mL leaves 1162.5mL to infuse over 2hrs.
1162.5mL/2hrs = 581.25mL/hr. Therefore, now (0900) you set the pump to infuse at 581mL/hr (or 581.2 or 581.3 depending on rounding policy) to infuse the remainder of the 3100mL within 8hrs post-injury(1100).
Then, at 1100 set the pump at 193.75mL/hr (3100mL/16hrs) to finish the order.
Very similar to your OP, except in the OP the rate is adjusted at 0400 (1hr post injury) whereas I read the question as "its been infusing at the 8hr rate, but was started 1hr late and has been going for 5hrs, how do you adjust the rate to ensure the 3100mL completes 8hr post-injury?"

But the fluids adjusted for being started an hr late was what my OP was? The fluids being started an hr late, made it so the rate needed to be 442.9 mL/hr over 7 hrs.

If, on the other hand, the infusion is started either too fast or too slow, when you receive the patient you will need to adjust the rate. For example, I'll use your patient, that should receive 3100 mL in the first 8 hours. If the infusion were started 1 hour post injury at 300 mL/hour as opposed to the calculated 442.9 mL/hour and arrives at your facility 3 hours post injury. He has received a total of 600 mL fluid. Based upon your initial calculations, and if the fluids were started at the time of injury, he should have received 1162.5; resulting in a degicit of 562.5 mL. In this situation you would need to adjust the rate to ensure that the patient receives the total calculated replacement fluid. To do this subtract the volume delivered from the calculated volume, and deliver the remainder over the remaining time, or: (3100-600)Ã·5, or 500 mL/hour.

Based on your calculations student_B â€“ which seem to match up mostly with what Chare said:

Your calculating the infusion being started on time, dividing by 8 hrs, but the infusion was started an hr late.

If they were started an hr late, you would need to adjust the formula to reflect initiation of fluids at the time of injury (0300), which was where I got the 442.9 mL/hr.

If you do the formula as if the pt received the fluids an hr late, but divide by 8 hrs, then you get 387.5 mL/hr and when you multiply that by the 5 hrs they've been running (0400 to 0900), you get 1937.5 mL infused.

3100 mL needs to infused in 8 hrs, so you take 3100 mL pt needs total â€“ 1937.5 that was infused already and get 1162.5 mL (so now I know where that came from in Chare's calculations). - But again, I don't get why you're dividing by 8 hrs, since fluids were started an hr late??

There are 2 hrs remaining in the first 8 hrs, so the remaining 1162.5 mL needs to run over 2 hrs = 1162.5/2 = 581.25 = 581.3 mL/hr over the next 2 hrs.

Except in Chare's calculations, she does (3100 â€“ 600)/5 = 2500/5 = 500 mL/hr

So, Student_B, your calculations match up with Chare's up until the end â€“

So, both of you calculated the rate as if the fluids were started at the time of injury and did 3100/8 â€“ 387.5 mL/hr. But since they were started an hr late, shouldn't it be 3100/7 = 442.9 mL/hr. Since, like I said in my OP, you have to adjust the formula to reflect initiation of fluids at the time of injury, which was 0300.

However, Chare's final calcuation takes the 3100 mL the pt needs to receive in 8 hrs, subtracts the 600 mL total the pt received at the incorrect rate of 300 mL/hr for 2 hrs, and then divides by 5 hrs (the amount of time the pt started receiving fluids (0400) to the time now at 0900)

So, I am totally lost!!!

If, as in my OP, the pt was burned at 0300 and fluids were started an hr late at 0400, and it is now 0900 (fluids have been going for 5 hrs)

The pt needs to get 3100 mL in the first 8 hrs.

Since fluids were started an hr late, instead of taking 3100/8, you take 3100/7 (you divide by 7 to make up for the hr that was missed).

3100 mL/7 hrs = 442.9 mL/hr given for the first 7 hours (again, given for 7 hrs because fluids were started an hr late).

So, fluids going at the adjusted rate of 442.9 mL/hr from the time of injury (0300) to the time now (0900) â€“ 6 hrs â€“ would be 442.9 mL/hr x 6 hrs = 2657.4 mL total.

But does that matter, because fluids were started an hr late, at 0400, and were started at the wrong rate of 300 mL/hr and ran for 2 hrs until the pt arrived at the hospital 3 hours post injury. So, pt hasn't really received that much.

Fluids being started an hr post injury and running for 2 hrs at the incorrect rate of 300 mL/hr means the pt received 600 mL/hr.

When pt arrived at the hospital 3 hrs post injury, I ASSUME, the fluid rate was changed to the correct adjusted rate of 442.9 mL/hr?

If pt arrived 3 hrs post injury, that would be 0600. So if fluids were running from 0600 to 0900 that is 3 hrs. If running at the adjusted rate that would be 442.9 mL/hr x 3 hrs = 1328.7 mL total.

600 mL infused at wrong rate + 1328.7 mL infused at adjusted rate = 1928.7 mL infused total. (so pt received 1928.7 mL total from time fluids were started at 0400 to time now at 0900)

Pt needs 3100 mL total in the first 8 hrs.

3100 mL - 1928.7 mL = 1171.3 mL still left to infuse

Pt burned at 0300 and it's 0900 (6 hrs), so there are 2 hrs remaining in the first 8 hrs.

To infuse 1171.3 mL in the remaining 2 hours: 1171.3 mL/2 hrs = 585.65 = 585.7 mL/hr.

So, the remaining 1171.3 mL needs to run at 585.7 mL/hr for the next 2 hrs in order for pt to receive the 3100 mL total in the first 8 hrs.

Where I am going wrong with this??

If fluids are started at the wrong rate and an hr late, do we not adjust the formula by adjusting the time to 7 hrs and divide by 7 still?

I know I am nagging and annoying! I'm sorry! I just really want to understand this! Thank you so much for all your help!!

student_B - Our instructor gave us the Parkland formula as:

(2 - 4 mL) x (wt in kg) x (TBSA%)

First half infused in first 8 hrs from time burn injury

Second half infused in next 16 hrs.

(Time starts from the time pt was injured!!)

But, the only way I've ever seen it and the only way she ever had us use it was 4 mL:

4 mL x (wt in kg) x (TBSA%)

First half infused in first 8 hrs from time of burn injury

Second half infused in next 16 hrs

You'll have to go by what your textbook/instructor says. But generally it seems to be 4 mL, not 2 - 4 mL.

Thanks for your help! Good luck with NS!!

KrCmommy522, BSN, RN · Nov 8, 2017

I guess I got too annoying in my persistence/confusion

chare · Nov 8, 2017

I guess I got too annoying in my persistence/confusion

No, not all. I haven't had opportunity to post. Hopefully tomorrow I can answer some of your questions.

KrCmommy522, BSN, RN · Nov 9, 2017

Ok! Great! Just thought maybe I scared you away because I definitely know my persistance can be annoying! :) No rush! Just happy I didn't scare you away! :) :)