Fluid requirements

Patient A --- (assuming a 70kg man) total fluid for case = 4500 with 10cc/kg for evap loss, 110cc/hr for maint and 1500cc for NPO deficit/bowel prep. Work in at least 1 liter before induction.

Patient B (mind you, I'm still learning and know this will probably be wrong) --- (70kg) Swan/A-line ... admin fluids based on PCWP/RAP as tolerated - albumin will be my friend. Estimate 1500-2500 for entire case???

Now - UT/JPP/jwk - how about the correct answer?

militarymd said:

Here's something for everyone to chew on (other than CRNA is better than AA vs MD).

What is your estimated fluid requirement for each of the following patients?

Patient A)

65 year old otherwise healthy man undergoing open total colectomy for CA. NPO afternight with a Golytely bowel prep. Operative time is 4 hours because of residents. EBL is 500 cc with a preop hct of 48%.

Patient B)

65 year old man with CHF and EF of 15% undergoing open total colectomy for CA. NPO afternight with a Golytely bowel prep. Operative time is 4 hours because of residents. EBL is 500 cc with a preop hct of 48%.

Meds. Lisinopril, metoprolol, digoxin, and PRN furosemide (he takes it probably once a week)

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Intraop fluids for pt A between 4-5 liters crystalloid and 500mL hespan for the blood loss. You may be able to extubate him.

For the sick dude, counterintuitively, the requirements are gonna be about the same....maybe a little less, if you are able....but your goal is to maintain hemodynamics and urine output intraop. Induce CHF? Oh well. Dont plan on extubating him, bring him to the ICU intubated, and diurese prn Better to do that than to induce intra-op mesenteric/myocardial ischemia, ATN, etc from poor perfusion. And schlogging his heart with inotopes while with holding fluids because your calculations say not to give any more fluid is the wrong thing to do.

PT B gets: 4500mL crystalloid and 500mL hespan.

Lost my last post but it works out being 7.3 L for first guy and 5 L for the second guy using colloids instead of crystalloid for blood loss (with an allowable blood loss around 1.5 L taking hemoconcentration into account).

Step III passed.

Pooped. 14 hr day ta-day. OUt for drinks. Latehars.

VentdependenT said:

Lost my last post but it works out being 7.3 L for first guy and 5 L for the second guy using colloids instead of crystalloid for blood loss (with an allowable blood loss around 1.5 L taking hemoconcentration into account).

Step III passed.

Pooped. 14 hr day ta-day. OUt for drinks. Latehars.

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Ditto on losing posts...my first lost post was very long, with explanations of fluid formulas, more comparing of Pt A & B, etc...posted again, lost, posted a little shorter 3rd time, LOST... .....hence the kinda abbreviated final post.

I think the central message should be....when you are learning fluid requirements, academic "experts" should teach you the formulas, but with a very important caveat: they are only guidelines, not requirements.

Doing an elective hernia repair on an 80 year old dude with a deft surgeon? Fluid replacement in a 30 minute case with no blood loss and virtually no insensible loss is really not that important. Same with any other short/no blood or insensible loss case.
But doing a long, open case is much, much different, and you have to accept the fact that if the dude has pre-op myocardial/pulmonary issues, you have to maintain perfusion, and the only way to do that is to keep fluid and blood in the intravascular space.
Blood pressure, HR, and urine output are more important than calculated numbers. You have to maintain the former, and most of the time you can throw out the latter.
ONLY ONE of my academic attendings during residency even came close to implying that to me during residency (out of about 20 attendings), and she was a pediatric cardiac anesthesiologist.
Yeah, we're "private practice slicks" alright. I consider that a compliment, considering the source of that comment.

militarymd said:

Now, now....you should know better than asking for the "correct answer". If the patient survives to walk out of the hospital, then that is the "correct answer".

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of course ...

I think someone should post a post similar to this at leats once or twice a wk. Especially you more experienced practictioners and 4yr residents. Im with you, use this board for something else besides "MDA vs CRNA" and "How long Anesthesia Boom will last".

jetproppilot said:

Intraop fluids for pt A between 4-5 liters crystalloid and 500mL hespan for the blood loss. You may be able to extubate him.

For the sick dude, counterintuitively, the requirements are gonna be about the same....maybe a little less, if you are able....but your goal is to maintain hemodynamics and urine output intraop. Induce CHF? Oh well. Dont plan on extubating him, bring him to the ICU intubated, and diurese prn Better to do that than to induce intra-op mesenteric/myocardial ischemia, ATN, etc from poor perfusion. And schlogging his heart with inotopes while with holding fluids because your calculations say not to give any more fluid is the wrong thing to do.

PT B gets: 4500mL crystalloid and 500mL hespan.

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That reasoning works well for me. I think you're right that the fluid requirements are about the same - it's just that patient B is going to need a good bit more time to deal with it than patient A. A lot of people I work with seem to have a problem with hespan, but these types of cases are perfect for it. I hate dumping in so many liters of fluid on these patients, and hespan is a great alternative.

Bowel preps screw up any patient, and 3rd space estimates are a guess at best. Urine output is your friend. If they're not peeing, the fluid's gonna keep coming.

nitecap said:

I think someone should post a post similar to this at leats once or twice a wk. Especially you more experienced practictioners and 4yr residents. Im with you, use this board for something else besides "MDA vs CRNA" and "How long Anesthesia Boom will last".

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Just how long will the boom last anyways?

Cant we flame up another CRNA vs MDA?

Jet I explained my reasoning too and once my post was gone so was any energy I had left. I say we get into crystalloids vs colloids in this thread as well. Price aside....for now. After all this is purely academic aint it?

Just paged my gf to the morgue.

Talking about Hespan...

Just how much are you comfortable giving?

i am surprised that you guys still talk about colloids.... didn't the SAFE trial put that to rest for a while? colloids are way too expensive


N Engl J Med 2004; 350:2247-2256, May 27, 2004

darn it - i wrote a long witty email and it got lost in transit - I am too tired to write it all again...

bottom line, i would give them each what they need - i don't use formulas (no evidence to show that those work)... unless they are under the age of 2 (just because you gotta be a bit anal in that age group).

I agree w/ previous poster = the worst thing that can happen is that you have some fluid overload that requires ventilation overnight w/ PEEP... no biggie

Talking about Hespan...

Just how much are you comfortable giving?

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Not sure if your question got answered but I think 20cc/kg is the theoretical limit before coagulopathy issues arise. At my institution we don't give beyond 1 L and, thinking a bit more about it, we don't use it all that much anyway.

Do others use hespan routinely? For some reason, I thought I read somewhere, that there might be more coagulopathy issues with hespan than originally thought but I don't have the time/energy to look for myself right now.

500ml seems to be the limit which I've seen infused (for the modern adult), due to the said coagulopathy issues.

militarymd said:

If anyone is interested, using pentaspan has less bleeding....

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The third generation starches may make use of colloids more attractive:

In patients undergoing major abdominal surgery, the influence of a new third-generation HES (HES 130/0.4) on tissue Po2 was compared with only saline solution (n = 21) for volume replacement [32] . By using flexible minimally invasive microsensoric Po2 catheters, tissue Po2 was monitored for 24 h after surgery. Although systemic hemodynamics and systemic oxygenation data were unchanged from baseline and were similar in both groups, tissue Po2 increased significantly in the HES-treated patients (maximum, +59%), whereas it decreased in the Ringer’s lactate solution (RL) group (maximum, −23%). It was concluded that intravascular volume replacement with HES 130/0.4 may improve tissue oxygenation during and after major surgical procedures, most likely because of improved microcirculation.

militarymd said:

You do realize that "microcirculation" is a surrogate endpoint, and not a gold standard endpoint.

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Can chew elaborate mang?

Here's an interesting article (more like abstract... haven't had access to the article yet...) on fluids, suggesting that some anesthesiologists may give too much fluid. Also suggests that the algorithms for fluid management are stupid.

http://www.anesthesia-analgesia.org/cgi/content/abstract/101/2/601?etoc&eaf

wish i had access to the actual article though...

beezar said:

Here's an interesting article (more like abstract... haven't had access to the article yet...) on fluids, suggesting that some anesthesiologists may give too much fluid. Also suggests that the algorithms for fluid management are stupid.

http://www.anesthesia-analgesia.org/cgi/content/abstract/101/2/601?etoc&eaf

wish i had access to the actual article though...

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That would be my mentor's article. UTSW's own Girish P. Joshi, the man with more letters at the end of his name than are letters IN his name.

militarymd said:

and I believe DS Prough leads the way there with the fluid stuff....

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DS does. Girish has his hands in too many cookie jars right now (president of two organizations, broad clinical research, courted for chairman's position at two Texas programs, etc.) to focus on one field.

Meds. Lisinopril, metoprolol, digoxin, and PRN furosemide (he takes it probably once a week)

What are your thoughts on the meds in these two pts.? Do you hold any?

I agree with metoprolol.
Its the lisinopril that I watch out for. I would hold it on the morning of surgery with this amount of fluid loss/shifts. If its taken in the evening then continue it. If its >20mg I start to worry about intraop hypotension mostly when taken on the day of surgery. This can change your fluid management. Do you guy/gals see the same with your patients?

Noyac said:

I agree with metoprolol.
Its the lisinopril that I watch out for. I would hold it on the morning of surgery with this amount of fluid loss/shifts. If its taken in the evening then continue it. If its >20mg I start to worry about intraop hypotension mostly when taken on the day of surgery. This can change your fluid management. Do you guy/gals see the same with your patients?

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I think intraoperative hypertension is more of a concern in a well regulated hypertensive patient...so I like them to take whatever they were taking preop...

An ACE is one that I absolutely want them to take if they were taking it before coming to surgery, as missing a dose could expose the risk of rebound hypertension.

militarymd said:

So you would hold 1 of 2 known medicines that is known to decrease mortality in CHF patients?

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There are plenty of studies which recommend holding ACE inh for surgery. Here's one:
http://www.ncbi.nlm.nih.gov/entrez/...list_uids=16099124&itool=iconabstr&query_hl=2

And this is just one article on the ASA website:
http://www.asahq.org/Newsletters/1999/08_99/fda0899.html

So with a peak effect at 6-8 hrs and a half life of 12 hrs (which can double in the elderly) this pt. would be covered. I don't make it an issue on the day of surgery but if I have a chance to see the pt. a day or more b/4 surgery, I tell them to cont. all meds at night but hold lisinopril on the day of surgery if it is over 20mg.

militarymd said:

So you would hold 1 of 2 known medicines that is known to decrease mortality in CHF patients?

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Unlike perioperative beta-blockade is there data detailing improved outcomes on patients maintaining their ACE - during the perioperative period (specifically intraop)?

Similarly, while preoperative hypertension can be extremely dramatic leading to fears of intraoperative hypertension the literature (from what I've been taught and read) seems to indicate that intraoperative hypOtension is much more worrisome.

I can see the arguments either way but, in my brief experience, intraoperative hypotension from ACE - inhibitors can be extremely profound with poor response to ephedrine/phenylephrine (small boluses of vasopressin, though, seems to work great).

Thoughts?

militarymd said:

No data...that's why my inital answer was "either or"....I was just jerking NOyac's chainn.

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Jerking my chain!
Are you sure?
Why would you want to jerk my chain?

And for Jet. I think that intraoperative hypotension is worse than hypertension in a chronic hypertensive.

Noyac said:

Jerking my chain!
Are you sure?
Why would you want to jerk my chain?

And for Jet. I think that intraoperative hypotension is worse than hypertension in a chronic hypertensive.

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Let me rephrase what I said....neither is good...but preoperatively, I'm WORRIED more about potential hypertension in the OR than hypo in a hypertensive patient.
All I can do is relay to you my experiences, and what I WANT to do is relay to the readers how I've practiced since finishing residency in 1996....what goes through my head, what I think are important variables, how I'd do a certain case, etc etc.
And on the subject of hypertensive medicines, based on experience of the thousands of cases I've done, I've found that I have less problems if the patient continues whatever HTN meds they are on. To date I've never seen intraoperative hypotension from a patient continuing their meds perioperatively so severe that I had to cancel the case, nor can I recall any postoperative morbidity attributed to a patient's HTN meds.
In my opinion intraoperative hemodynamic lability is less if the patient continues their HTN meds up to the operation.
If they are on a B blocker, are supposed to take it in the morning, and they forgot their med, I'll give them labetolol 200mg PO in day surgery when I see them. If they're on an ACE, forgot their meds, they get clonidine .2mg PO.

I've got a buddy who has a surgery center practice who gives clonidine .2mg PO to just about every adult patient because of his same observation of reducing intraoperative lability.

Again, not trying to justify anything. The jury's still out on this subject (except B blockers). I'm sure there are studies justifying both sides of the "What Non B Blocker Meds Should Be Continued" subject.
So until the subject is definitive, I'll continue doing what I'm doing since it has worked so far.

In the heart room, I've learned some tricks that arent written anywhere.
One is after the clamp comes off, if no spontaneous rhythm arises after about 30 seconds, I give atropine 2 milligrams. In my experience, for whatever physiologic reason, it seems to reduce the need for post-bypass pacing. Science or voodoo? Not really sure, but in my book it works in helping reestablish spontaneous myocardial activity.

Just my 2 cents.

jetproppilot said:

In the heart room, I've learned some tricks that arent written anywhere.
One is after the clamp comes off, if no spontaneous rhythm arises after about 30 seconds, I give atropine 2 milligrams. In my experience, for whatever physiologic reason, it seems to reduce the need for post-bypass pacing. Science or voodoo? Not really sure, but in my book it works in helping reestablish spontaneous myocardial activity.

Just my 2 cents.

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My goal is a slightly tachycardic rate, say 90-100, since myocardial compliance is less after bypass, so the heart is more like a pedi heart, at least temporarily. And I've yet to see the atropine trick cause a heart rate high enough to worry about tachycardia-induced myocardial ischemia.

.