Creatinine increase with diuretics?

[wamcp]

Stupid questions from a new intern but I can't find an answer to it even with extensive Googling search...

Do we have to be cautious with administering loop diuretics in patients with AKI due to CHF (assuming the mechanism is hypervolemic/prerenal from CHF)?

For example I had a guy with acute CHF exacerbation, no history of CKD.
Tried diuresing him the first day but he became anuric the next day, creatine went from 1.7 on admission to 4.5 the second day. Tried 120 mg IV total
On the third day we hit him with 300 mg IV total , creatinine was 7.
He ended up CMO (he refused dialysis, decided to choose DNR/DNI) and died on our floor that night..

So was there any bad effect on the kidneys with giving high dose lasix (like 200 mg IV total on the second day) for someone very oliguric or anuric/rising creatinine?
Do diuretics worsen kidney function in this context or bump the creatinine?

As a student I remember being told to be cautious in giving diuretics to someone with rising creatinine...is this an actual thing or is this just a caution to prevent a worsening pre-renal AKI due to excessive fluid loss from diuretics?

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[jdh71]

Stupid questions from a new intern but I can't find an answer to it even with extensive Googling search...

Do we have to be cautious with administering loop diuretics in patients with AKI due to CHF (assuming the mechanism is hypervolemic/prerenal from CHF)?

For example I had a guy with acute CHF exacerbation, no history of CKD.
Tried diuresing him the first day but he became anuric the next day, creatine went from 1.7 on admission to 4.5 the second day. Tried 120 mg IV total
On the third day we hit him with 300 mg IV total , creatinine was 7.
He ended up CMO (he refused dialysis, decided to choose DNR/DNI) and died on our floor that night..

So was there any bad effect on the kidneys with giving high dose lasix (like 200 mg IV total on the second day) for someone very oliguric or anuric/rising creatinine?
Do diuretics worsen kidney function in this context or bump the creatinine?

As a student I remember being told to be cautious in giving diuretics to someone with rising creatinine...is this an actual thing or is this just a caution to prevent a worsening pre-renal AKI due to excessive fluid loss from diuretics?

You can worsen a pre-renal condition with loop diuretics but sometimes you just don't know what's the problem for certain so you give some decent slugs of lasix hoping to provoke some kind of response but in bad cardio-renal syndrome you are simply in the middle of the place where you have tools to help fix the physiology effectively. It's like RV failure and PE, OMFG asthma, or hypotensive aortic stenosis. The problem is sitting where our interventions can't do a lot

 

[jdh71]

And NOT a stupid question. I've seen many of a stupid question around here and OP was not one.

 

[wamcp]

You can worsen a pre-renal condition with loop diuretics but sometimes you just don't know what's the problem for certain so you give some decent slugs of lasix hoping to provoke some kind of response but in bad cardio-renal syndrome you are simply in the middle of the place where you have tools to help fix the physiology effectively. It's like RV failure and PE, OMFG asthma, or hypotensive aortic stenosis. The problem is sitting where our interventions can't do a lot

Thansk for the answer...so are you saying we should have no qualms in DIRECTLY harming the kidneys with lasix itself? As in furosemide has no toxic effect on them the same way acyclovir does? Can I freely pound my suddenly anuric with hypervolemia patients with 100 IV lasix at a time??

 

[Cnote81]

in a situation like that, would you guys consider FeUrea and urine sodium early and maybe add on an inotrope? i'm on CHF now and from the cardiorenal pts i've seen, lasix has improved their creatinine assuming their baseline renal function was normal.

 

[jdh71]

Thansk for the answer...so are you saying we should have no qualms in DIRECTLY harming the kidneys with lasix itself? As in furosemide has no toxic effect on them the same way acyclovir does? Can I freely pound my suddenly anuric with hypervolemia patients with 100 IV lasix at a time??

Correct. In fact I consider a "lasix challenge" of anything less than 120mg to be farting around.

 

[jdh71]

in a situation like that, would you guys consider FeUrea and urine sodium early and maybe add on an inotrope? i'm on CHF now and from the cardiorenal pts i've seen, lasix has improved their creatinine assuming their baseline renal function was normal.

After/pre load reduce with nitrates, dobutamine, and lasix if you can get the patient to tolerate.

 

[jdh71]

We should get an @Instatewaiter opinion up in this bish. He trains in the temple of the most high heart failure gods.

 

[JacobSilge]

The big caveat here is making sure that you have the diagnosis right. If it is really cardiorenal syndrome (intravascular volume overload with venous congestion of the renal vasculature), then giving more Lasix really is the right way to go as the patient's threshold for effect is going to be higher given the AKI. The only way Lasix is going to make the creatinine progressively worsen in this situation is if the patient develops AIN from Lasix, but that would take a few days.

That being said, the situation you described sounds an awful lot like the patient might have been in cardiogenic shock given the rapid worsening of the creatinine and the fact that he died a few days later. In that case Lasix isn't going to do much unless you warm the patient up first with an inotrope, though I'd still tend to give a try with ~160mg or so of IV Lasix to see what you can do.

The third possibility is that the patient was actually intravascularly volume depleted with signs of extravascular volume overload. Exam can be difficult, especially when you have to differentiate JVD from TR in someone with a large neck to begin with. Peripheral and pulmonary edema can be present regardless of intravascular volume status. TTE should help differentiate. In this case, the Lasix could further exacerbate intravascular volume depletion and further worsen renal function.

 

[Instatewaiter]

We should get an @Instatewaiter opinion up in this bish. He trains in the temple of the most high heart failure gods.

Agree with JDH that it's not a stupid question and the cardiomyopathy folks have to deal with this quite a lot. In volume overload states, diuresis is going to help improve your creatinine by decreasing renovascular congestion. You should only see minimal increases in Cr unless they're not volume overloaded or you're diuresing too fast.

There are a few issues that can confuse the situation
1) First, the rate of diuresis can't far exceed the rate of reaccumulation from the periphery. In otherwords, you can't pull 7 liters of fluid off a day if the patient can only pull 2 liters out of their extravascular edema. You're going to run into problems and the kidney is going to act as if it is pre-renal. Occasionally we have to give people a diuretic holiday, let them reaccumulate intravascularly and hit them again with diuresis. This is one of the common mistakes we see on IM- you see the Cr going up and assume the patient is dry when they are still volume overloaded but you've been pulling more fluid than they can re-accumulate.

2) The second issue is in restrictive cardiomyopathy. These people have a very, very narrow therapeutic window where there is a gentle balance between volume overloaded and poorly filled. These guys need much higher filling pressures otherwise their cardiac output goes to crap. Often, you have to run them a smidge wet to have them survive. If you pull a little too much fluid and their preload drops below where they can fill. Their cardiac output goes to crap and they get worse. This makes the above issue of reaccumulation magnified.

In the patient from the OP there could have been a few things going on. First, the patient could actually not have been volume overloaded (Lots of TR causing big V waves on the JVP- you can still eval a JVP in the setting of TR, you just need to look for the mean JVP)? It's easy to play Monday Morning Quarterback but after that first day you should take a step back. A Cr bump from 1.7 --> 4 is higher than comfort. A slight increase would be expected if they were diuresing. If they became aneuric, you have to wonder if the volume status was what you thought it was. At this point, doing a right heart cath to confirm your volume is what you think it is would be appropriate. This will also give you cardiac output/index to tell you if they are in shock. Younger people can sometimes fool you. I've seen 30 years olds with an index of 1.1 who were walky-talky.

If the patient is volume overloaded, diuresis alone shouldn't cause the cr to rise unless the patient was severe restrictive CM. When the Cr rises that acutely, you need to re-eval your initial premise. Even in cold/wet cardiogenic shock, you shouldn't see the Cr rising unless they are getting much more shocky. In those situations it's not subtle- the liver function worsens, they develop a gap from lactic acidosis, the Cr rises, extremities become cold etc.

The second thought is that there was something else going on besides just HF. You'll see that in your patients with an acute GFR of 0 that their creatinine increases by only 1-2 mg/dl per day. To go from 1.7 --> 7 in 2 nights is a little brisk. I wonder if the patient didn't have any thing else which would have contributed (extra muscle breakdown causing more Cr excretion?).

Final thought is preload dependent states like acute right heart failure (PE, RV infarct) or tamponade can mimic HF with edema and elevated JVP but diuresing them makes them much worse.

 

[Instatewaiter]

A few words on diuretics for new interns-
The higher the Cr, the higher the dose of lasix needed. A Cr of 4 is going to require very high doses of lasix (120 is a good starting point but may not do it)

Loops have a threshold where they will work, which is patient dependent. If 40mg didn't work, another 40 wont either. You need to raise the dose to above the threshold to get effect.

Don't be afraid of the lasix drip. It is a great way to prevent fluid shifts which muddy the water.

If a person is coming in with frequent HF admisssions on lasix and is compliant, switch them to torsemide. When you get volume overloaded, your gut becomes edematous. The lasix is poorly absorbed, doesn't reach the threshold for diuresis and you get into this nasty cycle (less absorption, more fluid, more gut edema, less absorption). Torsemide is much better absorbed despite gut edema and can prevent these frequent hospitalizations.

For synergy, thiazides can be added to loops. Give the thiazide 30 min prior to hte loop. In all honesty it doesn't matter much which thiazide you use. Metolazone is pretty cheap and works well. Diuril is very expensive and works about the same. HCTZ actually works very well (doses of 50-100mg for booster) and is dirt cheap. Don't do this unless you're getting to pretty big doses of loops (lasix 100+). We see Mount Saint Elsewhere add metolazone to lasix 40mg daily all the time. Don't do that.

AIN from lasix is incredibly rarely (seen it about 2 times) usually from the sulfonamide group. In these cases ethacrinic acid can be used.

 

[Instatewaiter]

in a situation like that, would you guys consider FeUrea and urine sodium early and maybe add on an inotrope? i'm on CHF now and from the cardiorenal pts i've seen, lasix has improved their creatinine assuming their baseline renal function was normal.

FEurea isn't going to tell you too much. FEurea is going to be low in HF as well as dehydration. So it doesn't really help you distinguish. Urine sodium is going to be falsely high if you are actually diuresing them.

Inotropes are a mixed bag. You need to realize you are actually giving someone something that increases their mortality. Yes the numbers get better but to what end? You're literally killing a few of them. For those patients that really need it because they are in true cardiogenic shock (ie a cardiac index in the 1.5 range) fine. But a little cool HF with an index of 1.9ish can be turned around with afterload reduction and holding their BB. Afterload reduction should be the first step (captopril/isdn/hydral or nipride in the ICU).

Thansk for the answer...so are you saying we should have no qualms in DIRECTLY harming the kidneys with lasix itself? As in furosemide has no toxic effect on them the same way acyclovir does? Can I freely pound my suddenly anuric with hypervolemia patients with 100 IV lasix at a time??

As above, AIN with lasix is exceedingly rare. If you are sure they are volume overloaded, you occasionally need to give them very high doses to open them up. A good rule of thumb is that if they haven't put out urine in about an hour, you need to give them a higher dose.

 

[Instatewaiter]

Other cardiogenic shock pearls for interns:
- Get them in sinus rhythm

- If the patient doesn't have an appropriate HR compensation (ie they're rate is like 65 but are shocky) and they have an ICD or PPM, increase the backup rate to 80 or 90 bpm temporarily. Remember CO~ HR x SV.

- The caveat to the above is that people sometimes don't tolerate RV pacing very well especially in diastolic dysfunction, restriction and AS (things that need the atrial kick). So, if they just suddenly are tanking and their volume of RV pacing is increasing, it may be time to think about an atrial lead.

- Nipride is a wonderdrug. It should be your go to drug for cardiogenic shock. It will drastically raise your CO, lower your pulmonary pressures, reduce the regurgitant volume of MR and AI, improves output in AS, and unlike inotropes doesn't kill people. Basically it fixes most of the problems in cardiogenic shock.

- IABPs work great for cardiogenic shock as well. Don't be afraid to use them.

 

[jdh71]

Fantastic!

 

[jdh71]

IABPs work great for cardiogenic shock as well. Don't be afraid to use them.

We won't be putting them in 😉

 

[wamcp]

Thank you all for teaching me these things. It's all quite overwhelming to me. It seems on wards, anyone who gets truly sick are kicked up to a higher level o fcare (appropriately of course). But this means since I never had a CCU rotation I am woefully inexperienced and wish I could learn firsthand how to manage these patients.

I almost feel traumatized that this guy died because I didn't really know the pathophys going on for him (my senior never said anything about suspecting my patient being in cardiogenic shock, didn't think he was sick enough to transfer him to CCU, so we signed out that day and the next morning we found out he died).

I am very frustrated that there are lots of things that I don't even know that I don't know, and I am not sure how to address this. I have been reading Marini's Crit Care Essentials to try to get some more insight/'book knowledge' but it feels inadequate without being in the ICU (MICU rotation is later in the year). Do you guys have any books to recommend so I don't end up killing patients in the future?

 

[JacobSilge]

Do you guys have any books to recommend so I don't end up killing patients in the future?

I don't think a book is going to help with this - you are in residency precisely to learn these things! I would advise trying to follow along with what happens to your patients once they are transferred to the ICU.

 

[Bostonredsox]

Correct. In fact I consider a "lasix challenge" of anything less than 120mg to be farting around.

Agreed.
Hit them hard with diuretics, 40-60q8 or something of that nature. If no response by morning dialyse them. I don't even wait the second day. If 24 hours of lasix yielded a tripling of cr and more importantly, no uop, stick and ij in and run them.

 

[Bostonredsox]

We won't be putting them in 😉

I = we and thus we have put in 2 😉 actually a simple procedure even at bedside. I just have has xray tech come up and take pics once I'm in and readjust with the films at bedside. Poor mans fluoro in the icu. Most all times cardio handles but have had 2 that would have died in the 25 min it took cardio to get there

 

[jdh71]

I = we and thus we have put in 2 😉 actually a simple procedure even at bedside. I just have has xray tech come up and take pics once I'm in and readjust with the films at bedside. Poor mans fluoro in the icu. Most all times cardio handles but have had 2 that would have died in the 25 min it took cardio to get there

I'm sure it's not rocket science. But I've never been shown how and everywhere I've been cards guards this kind of thing very territorially. Comedy.

Anyway that's pretty cool you've put a few in. Basically "wire" over a fem stick?? Then X-ray to check the level??

 

[Instatewaiter]

I'm sure it's not rocket science. But I've never been shown how and everywhere I've been cards guards this kind of thing very territorially. Comedy.

Anyway that's pretty cool you've put a few in. Basically "wire" over a fem stick?? Then X-ray to check the level??

It's an easy procedure but can have a lot of complications if you chose your spot wrong, or are not used to femoral sticks etc. Also, you need the X-ray tech to stick around because if you turn the pump on and it's too far, you can cause some nasty complications.

Femoral stick- wire through the needle.
Put in a sheath over a wire.
Long Wire up to the aortic arch
Run the pump up the wire to the arch
Flush the pump
Attach the pump to the machine.

 

[Bostonredsox]

It's an easy procedure but can have a lot of complications if you chose your spot wrong, or are not used to femoral sticks etc. Also, you need the X-ray tech to stick around because if you turn the pump on and it's too far, you can cause some nasty complications.

Femoral stick- wire through the needle.
Put in a sheath over a wire.
Long Wire up to the aortic arch
Run the pump up the wire to the arch
Flush the pump
Attach the pump to the machine.

/nod. I premeasure the length I think it will take to reach the arch, stick, wire same as a fem art line, sheath, exchange introducer wire for long wire, run up pump, hold while X-ray tech snaps a shot, adjust if need to then take another pick, flush, connect, sew.

Were a small community shop and my cards guys don't care about guarding it as they know I'm doing it to save pt, I personally am not reimbursed for the procedure. And as with emergent tvp's, it saves them a trip in the middle of the night or atleast makes them not have to rush and call in cath team. Biggest concern is placement. Too high and you occlude carotids they stroke. Too low and you occlude renals and you fry the beans.