When you suspect kidney stones

[iaskdumbquestions]

When do you get a CT scan? I've heard and seen everything from: always, first time they've had stone, systemically ill, hydronephrosis on bedside ultrasound. I've also seen people with mild hydro and suspected stone go home.

The practice pattern varies wildly and I'm trying to gain a better understanding of what is important and what is not. What do you look for, what are your red flags, when do you scan?

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[WilcoWorld]

In suspected renal colic I order a CT for:
- First time stones
- Concern for co-existing infection
- Intractable severe pain
- History of needing Urosurgical intervention/having indwelling hardware
- When I'm not really sure it's a stone

Stated otherwise - I'll skip the CT for a patient with recurrent stones who has a non-toxic appearance and a clean UA (only shows blood), and whose pain is reasonably well controlled.

 

[iaskdumbquestions]

In suspected renal colic I order a CT for:
- First time stones
- Concern for co-existing infection
- Intractable severe pain
- History of needing Urosurgical intervention/having indwelling hardware
- When I'm not really sure it's a stone

Stated otherwise - I'll skip the CT for a patient with recurrent stones who has a non-toxic appearance and a clean UA (only shows blood), and whose pain is reasonably well controlled.

So for example, if someone with suspected stone comes in and they've had a stent before, you'll get the CT every time? What if the UA shows no blood/infection?

Thanks for answering!

 

[RustedFox]

In suspected renal colic I order a CT for:
- First time stones
- Concern for co-existing infection
- Intractable severe pain
- History of needing Urosurgical intervention/having indwelling hardware
- When I'm not really sure it's a stone

Stated otherwise - I'll skip the CT for a patient with recurrent stones who has a non-toxic appearance and a clean UA (only shows blood), and whose pain is reasonably well controlled.

The bolded/italicized/underlined is the most important. It'd be a bummer to have a "recurrent stone" turn out to be a AAA.

You do the scan to make the diagnosis and rule-out the other diagnoses.

 

[emergentmd]

When do you get a CT scan? I've heard and seen everything from: always, first time they've had stone, systemically ill, hydronephrosis on bedside ultrasound. I've also seen people with mild hydro and suspected stone go home.

The practice pattern varies wildly and I'm trying to gain a better understanding of what is important and what is not. What do you look for, what are your red flags, when do you scan?

CT is the New Xray right?

I would say I CT 95% of the time. The size and location matters for outpt management.

 

[WilcoWorld]

So for example, if someone with suspected stone comes in and they've had a stent before, you'll get the CT every time? What if the UA shows no blood/infection?

Thanks for answering!

No, not every time. For example, if it's a non-toxic appearing woman in the 1st trimester of pregnancy who has no signs of infection on UA, whose pain has resolved, and who has a reassuring ultrasound.

But a prior urologic procedure significantly increases my likelihood of scanning.

 

[GeneralVeers]

I only skip the scan on smart patients who have insight into their disease/symptoms and are reasonable.

For the other 98% I scan every single one, every time.

 

[gutonc]

I only skip the scan on smart patients who have insight into their disease/symptoms and are reasonable.

For the other 98% I scan every single one, every time.

98% seems generous.

 

[da8s0859q]

CT is the New Xray right?

I would say I CT 95% of the time. The size and location matters for outpt management.

I only skip the scan on smart patients who have insight into their disease/symptoms and are reasonable.

For the other 98% I scan every single one, every time.

+1 to both of these. I sleep better at night in the process.

 

[Venko]

For me, if based on history and physical or other I am confident that the diagnosis is a kidney stone and I simply want to evaluate for complications of stone, then I use ultrasound

If I am not confident in the diagnosis or because of other factors (age, illness, comorbidities, exam) I need to evaluate the abdomen beyond simply for stones, I get a ct.


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[EMDOC17]

So if frequent recurrent stones with no surgical intervention in the past and they say "this is exactly like my previous stones" than no CT if patient is on board if no concurrent UTI and no renal dysfunction. On board meaning worsening pain or new symptoms they are back for their CT. I also look to make sure they have had a ct before confirming an actual obstructing stone and not having frequent ED visits for pain conditions. This actually is a decent number. If they don't meet that than CT. Never US unless pregnant.

 

[Venko]

Ultrasound has a role in evaluation of a stone if no Ct is done as it can grade hydronephrosis which may alert you that the patient needs urgent urologic care to protect the kidneys long term functioning.


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[Angry Birds]

Almost always scan.

 

[turkeyjerky]

Ultrasound has a role in evaluation of a stone if no Ct is done as it can grade hydronephrosis which may alert you that the patient needs urgent urologic care to protect the kidneys long term functioning.


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Could you elaborate on this?

 

[Rendar5]

Could you elaborate on this?

If hydro it's been shown to have higher likelihood of interventional tx. I've seen some suggest hydro =auto follow-up and no hydro = PMD follow-up. That said all my urologists want CT so I CT.

 

[TooMuchResearch]

If hydro it's been shown to have higher likelihood of interventional tx. I've seen some suggest hydro =auto follow-up and no hydro = PMD follow-up. That said all my urologists want CT so I CT.

Sometimes I let them obtain CT in follow up.

 

[TooMuchResearch]

Could you elaborate on this?

NEJM 2014;371[12]:1100

 

[deleted109597]

There's the need to diagnose, and then the need to prognosticate. I mean, sick ones get scans, that's a no brainer. The relatively well? Who cares if it is 4mm vs 7mm. It will either pass or it won't, and when it doesn't pass, they'll get another scan. The patient needs to be on board of course, but it's not like we couldn't diagnose stones prior to the advent of CT scanners. And since IVPs were a pain to get, you only got them when you needed, unlike clicking the box for the donut of truth.

 

[Venko]

If severe hydronephrosis, a person may appear well if well functioning second kidney. The creatinine may be normal. However, it is believed that significant hydronephrosis can cause permanent impairment if not addressed in some people. To that end, once you know the diagnosis is an obstructing kidney stone...consider: (1) renal failure, (2) infection of stone, (3) significant structural impairment (i.e. Hydronephrosis), (4) intractable pain as reasons for very short urology follow up, potentially even in observation unit or in ED consultation (this will depend you your patient and your system).

So, if I know the diagnosis, then I check electrolytes, ultrasound / POCUS (not to diagnose, but to evaluate for severe hydronephrosis), urine, and manage pain.

In my experience, clinical appearance can be deceiving because of the functional second kidney....




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[deleted109597]

In my experience, clinical appearance can be deceiving because of the functional second kidney....

Hydro hurts, man. It's not renal colic anymore at that point. It's constant, unrelenting flank pain, more like pyelo.
You can diagnose it clinically as well. Maybe not as accurately as with US (which I do use instead of CT frequently), but it's like the painless MI. Everybody is going to miss those.

 

[Venko]

Hydro hurts, man. It's not renal colic anymore at that point. It's constant, unrelenting flank pain, more like pyelo.
You can diagnose it clinically as well. Maybe not as accurately as with US (which I do use instead of CT frequently), but it's like the painless MI. Everybody is going to miss those.

I have met many many people with moderate and severe hydronephrosis whose pain was controlled with narcotics and nsaids but were diagnosed via ultrasound or ct.

If you don't image everyone in one form or another, you're not in a position to know how many people may have hydronephrosis that went undiagnosed. You also won't know how many will have harm from not intervening because the other kidney will cover the needs until something else happens down the road which may be quite a long way down the road.



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[GTP]

I have this problem often. We have some frequent fliers with kidney stones and some are drug seekers. Some come few times a week or at least once a week. Some are legit some are not. right now we often play the game of if you have been Ct'd a lot recently, we will just do a UA and bedside ultrasound. In real life I wonder if I will just light these people up as an attending even though it's on a weekly basis. I've met people who have had no blood in the urine and had 1 cm stone and reasonable pain control that the ct scan was absolutely necessary. I've met people who look absolutely comfortable who have had hydro and a 5 mm stone. It seems silly to explain an entire paragraph in my MDM why I'm not getting a ct and potentially risk being sued when I could just save myself stress and time and just spin them every time and I'd be protected. Thoughts?

 

[TooMuchResearch]

I have this problem often. We have some frequent fliers with kidney stones and some are drug seekers. Some come few times a week or at least once a week. Some are legit some are not. right now we often play the game of if you have been Ct'd a lot recently, we will just do a UA and bedside ultrasound. In real life I wonder if I will just light these people up as an attending even though it's on a weekly basis. I've met people who have had no blood in the urine and had 1 cm stone and reasonable pain control that the ct scan was absolutely necessary. I've met people who look absolutely comfortable who have had hydro and a 5 mm stone. It seems silly to explain an entire paragraph in my MDM why I'm not getting a ct and potentially risk being sued when I could just save myself stress and time and just spin them every time and I'd be protected. Thoughts?

Well appearing, comfortable after analgesic, afebrile, normal renal function, blood on UA and no signs infection, discussed with patient, offered CT, pt opts for no imaging.

 

[Kuba]

I'm more likely to CT if older (more likely alternate dx,) sick appearing, low confidence in dx. I don't always scan first time stones, if young, typical presentation and mild to mod hydro on bedside US I dc. Otherwise, in the circle of truth they go. I'd say roughly 30% stones get CT with me.

 

[BoardingDoc]

NEJM 2014;371[12]:1100

That study just compares CT to US. The question was about the benefit of doing an US if you're already NOT doing the CT scan. If there's a study out there that took everyone with a suspected stone, ultrasounded all of them and then showed that detection of hydro was indicative of badness down the line... that would be useful.

 

[BoardingDoc]

I have this problem often. We have some frequent fliers with kidney stones and some are drug seekers. Some come few times a week or at least once a week. Some are legit some are not. right now we often play the game of if you have been Ct'd a lot recently, we will just do a UA and bedside ultrasound. In real life I wonder if I will just light these people up as an attending even though it's on a weekly basis. I've met people who have had no blood in the urine and had 1 cm stone and reasonable pain control that the ct scan was absolutely necessary. I've met people who look absolutely comfortable who have had hydro and a 5 mm stone. It seems silly to explain an entire paragraph in my MDM why I'm not getting a ct and potentially risk being sued when I could just save myself stress and time and just spin them every time and I'd be protected. Thoughts?

If you have frequent fliers with kidney stones who you're suspecting malingering, I would absolutely CT them to find out. If they are in fact having recurrent stones, I would be asking why they haven't seen a urologist about this yet. This way you've either caught them in a lie and they hopefully stop coming back when they get no narcotics, or you've found a real problem and referred them to a specialist for proper care. Win win.

 

[deleted109597]

Win win.

While it hasn't happened yet AFAIK, there were young women I saw in residency who had already had 40+ scans in their first 4 decades of life. One had 8 in a year. So at some point we probably are causing actual harm. But a single scan? I don't lose too much sleep over it.

 

[BoardingDoc]

While it hasn't happened yet AFAIK, there were young women I saw in residency who had already had 40+ scans in their first 4 decades of life. One had 8 in a year. So at some point we probably are causing actual harm. But a single scan? I don't lose too much sleep over it.

I'm not sure how you interpreted my "win win" statement based on your response. My point was that the patient either has recurrent stones and then gets the needed followup with urology (and hopefully a plan on avoiding more scans / ED visits in the future) or they're malingering and opiate seeking. In that case, they will probably stop coming to your ED after they stop getting opiates which is another win because A: they've stopped coming in with a presentation that likely merits abdominal radiation, and B: you're not feeding an addiction which is likely to kill them far faster than any side effect of those aforementioned scans.

 

[TooMuchResearch]

While it hasn't happened yet AFAIK, there were young women I saw in residency who had already had 40+ scans in their first 4 decades of life. One had 8 in a year. So at some point we probably are causing actual harm. But a single scan? I don't lose too much sleep over it.

I scanned someone a few days ago who has had 50+ chest/belly scans in the past few years. Of course I didn't know that until after the scan was done...the CT report was shockingly similar to the one done the previous day at another local ED (pt failed to mention this workup for exact same complaint 24 hours prior).

 

[deleted109597]

I'm not sure how you interpreted my "win win" statement based on your response. My point was that the patient either has recurrent stones and then gets the needed followup with urology (and hopefully a plan on avoiding more scans / ED visits in the future) or they're malingering and opiate seeking. In that case, they will probably stop coming to your ED after they stop getting opiates which is another win because A: they've stopped coming in with a presentation that likely merits abdominal radiation, and B: you're not feeding an addiction which is likely to kill them far faster than any side effect of those aforementioned scans.

I cannot force urology to follow up with these patients. Maybe you can. And I can't convince the other people that work at my ED to stop showering them with narcotics. Or to stop scanning them frankly. All my methods do is force the patients to ask who is working that day. I guess it's a win for me, but not for the system.

 

[Angry Birds]

I generally put the onus on the patients. I tell them, "I'm going to order a CT scan. If you have recurrent stones, you should talk to your urologist about whether or not you always need to get a CT scan, due to the issue of radiation. That way, if your Urologist says you don't always need a CT scan, then you can notify the ER doctor that you'd rather opt out of getting the scan. But, as an ER doctor, I need to err on the side of getting one, unless you and your Urologist tell me otherwise."

Then, I can document in the chart: "CT scan ordered but patient refused due to having recurrent stones and repeat CT scans, and understanding with their urologist that repeat CT scans not needed. This is reasonable given the patient's history and the concern about radiation burden and risk of cancer later in life, so patient's decision respected." Something along those lines.

If I see in the system that they've had a million scans, then I focus on this a bit more and say: "You've had a lot of CT scans. Have you talked to your Urologist about this? As a matter of routine, I order CT scans in the ER for kidney stone patients, but you should consider the radiation burden...." etc etc

 

[Angry Birds]

I scanned someone a few days ago who has had 50+ chest/belly scans in the past few years. Of course I didn't know that until after the scan was done...the CT report was shockingly similar to the one done the previous day at another local ED (pt failed to mention this workup for exact same complaint 24 hours prior).

You should scan the 51st time in order to diagnose the tumor.

 

[Petypet]

While it hasn't happened yet AFAIK, there were young women I saw in residency who had already had 40+ scans in their first 4 decades of life. One had 8 in a year. So at some point we probably are causing actual harm. But a single scan? I don't lose too much sleep over it.

darwinism

 

[turkeyjerky]

darwinism

Unfortunately natural selection doesn't work like that--usually these types are very successful at passing on their genes

 

[GeneralVeers]

Unfortunately natural selection doesn't work like that--usually these types are very successful at passing on their genes

Right. You have to eliminate them from the gene pool before they make welfare checks....I mean babies.

 

[Rendar5]

My last patient of my shift had bilateral ureteral stones but hydro and symptoms only on one side. Second time in my career. So ultrasound would've sent her home. Ct got her admitted and her stones treated the same day.

 

[Angry Birds]

My last patient of my shift had bilateral ureteral stones but hydro and symptoms only on one side. Second time in my career. So ultrasound would've sent her home. Ct got her admitted and her stones treated the same day.

I had my first patient with uretral stone with severe hydro on one side but who had zero RBCs in urine. I was surprised.

 

[Venko]

My last patient of my shift had bilateral ureteral stones but hydro and symptoms only on one side. Second time in my career. So ultrasound would've sent her home. Ct got her admitted and her stones treated the same day.

You're supposed to scan both kidneys because comparison can detect symmetrical hydronephrosis which is less likely to be ureterL stone based. This can be seen with other conditions like pelvic tumors or pregnancy. Having comparison is important. So if done right, both would've been imaged by POCUS and the patient would get intervention or advanced imaging.


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[Rendar5]

You're supposed to scan both kidneys because comparison can detect symmetrical hydronephrosis which is less likely to be ureterL stone based. This can be seen with other conditions like pelvic tumors or pregnancy. Having comparison is important. So if done right, both would've been imaged by POCUS and the patient would get intervention or advanced imaging.


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Actually the patient would've gone home and followed up outpatient with one sided hydro and clear suspicion of stone

 

[Venko]

Actually the patient would've gone home and followed up outpatient with one sided hydro and clear suspicion of stone

Whether done outpatient, via EDOU, admitted, or out of the ED will be dependent upon your location and your urology practice. But the point would be that a person with hydronephrosis even unilateral should get evaluation to ensure it resolves quickly and repeat creatinine measures over a short time.

In my current shop, I can use our EDoU. At the VA I previously worked we would have quick outpatient follow up with urology. At the county I previously worked, it was really hard to get follow up so these folks got urology consult in the ed or in the hospital.


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[Rendar5]

My point was that the disposition changed based on the Ct presence of stones in bilateral ureters. Ultrasound would've lead to an entirely different dispo pathway and given the wrong diagnosis (unilateral stone with hydro). This was a patient who could not afford to be sent home for close follow-up on Monday, and I work someplace where I can easily get that.

 

[TooMuchResearch]

My point was that the disposition changed based on the Ct presence of stones in bilateral ureters. Ultrasound would've lead to an entirely different dispo pathway and given the wrong diagnosis (unilateral stone with hydro). This was a patient who could not afford to be sent home for close follow-up on Monday, and I work someplace where I can easily get that.

I'm not going to scan every unilateral flank pain with history of stones to look for something that should cause bilateral pain and is a rare diagnosis. If creatinine is fine and no infection, still okay to go with strict come back if worse instructions.

 

[Rendar5]

I'm not going to scan every unilateral flank pain with history of stones to look for something that should cause bilateral pain and is a rare diagnosis. If creatinine is fine and no infection, still okay to go with strict come back if worse instructions.

My n of 2 had patients present with unilateral pain and hx of interventions. You're dealing with rare bad outcomes from either failing to scan or rare bad outcomes from excess radiation. I have no issues with people not scanning repeat kidney stone sufferers for situations as you specified above. I almost always scan them though because all my urologists want the scan and will get it if I don't.

 

[Venko]

[QUOTE="TooMuchResearch, post: I'm not going to scan every unilateral flank pain with history of stones to look for something that should cause bilateral pain and is a rare diagnosis. If creatinine is fine and no infection, still okay to go with strict come back if worse instructions.[/QUOTE]

Could i encourage you to put an ultrasound transducer on both flanks in addition? It won't take you much time and you could identify a person with significant hydronephrosis and get them more urgent attention either in ED, or outpatient?